First and second heart sound. Auscultation of the heart and blood vessels. Origin of heart sounds and murmurs. See what "Heart sounds" are in other dictionaries
Characteristics of heart sounds.
The opening of the valves is not accompanied by distinct fluctuations, i.e. almost silently, and the closure is accompanied by a complex auscultatory picture, which is regarded as I and II tones.
Itone occurs when the atrioventricular valves (mitral and tricuspid) close. Louder, longer lasting. This is a systolic tone, as it is heard at the beginning of systole.
IItone It is formed when the semilunar valves of the aorta and pulmonary artery close.
Itone called systolic and according to the mechanism of formation consists of 4 components:
main component- valvular, represented by amplitude oscillations resulting from the movement of the mitral and tricuspid valve cusps at the end of diastole and the beginning of systole, and the initial oscillation is observed when the mitral valve cusps are closed, and the final oscillation is observed when the tricuspid valve cusps are closed, therefore, the mitral and tricuspid components are isolated;
muscle component– low-amplitude oscillations are superimposed on high-amplitude oscillations of the main component ( isometric ventricular tension, appears in about 0.02 sec. to the valve component and layered on it); and also arise as a result asynchronous ventricular contractions during systole, i.e. as a result of contraction of the papillary muscles and the interventricular septum, which ensure the slamming of the cusps of the mitral and tricuspid valves;
vascular component- low-amplitude fluctuations that occur at the time of opening of the aortic and pulmonary valves as a result of vibration of the walls of the aorta and pulmonary artery under the influence of blood flow moving from the ventricles to the main vessels at the beginning of the ventricular systole (exile period). These oscillations occur after the valve component after about 0.02 seconds;
atrial component- low-amplitude oscillations resulting from atrial systole. This component precedes the valvular component of the I tone. It is detected only in the presence of mechanical atrial systole, disappears with atrial fibrillation, nodal and idioventricular rhythm, AV blockade (lack of atrial excitation wave).
IItone called diastolic and occurs as a result of the slamming of the cusps of the semilunar valves of the aorta and pulmonary artery. They begin diastole and end systole. Comprises 2nd components:
valve component occurs as a result of the movement of the valves of the semilunar valves of the aorta and pulmonary artery at the moment of their slamming;
vascular component associated with the vibration of the walls of the aorta and pulmonary artery under the influence of the flow of blood directed towards the ventricles.
When analyzing heart tones, it is necessary to determine them quantity, find out what tone is first. With a normal heart rate, the solution to this problem is clear: I tone occurs after a longer pause, i.e. diastole, II tone - after after a short pause, i.e. systole. With tachycardia, especially in children, when systole is equal to diastole, this method is not informative and the following technique is used: auscultation in combination with palpation of the pulse on the carotid artery; the tone that coincides with the pulse wave is I.
In adolescents and young people with a thin chest wall and a hyperkinetic type of hemodynamics (increased speed and strength, during physical and mental stress), additional III and IV tones (physiological) appear. Their appearance is associated with the fluctuation of the walls of the ventricles under the influence of blood moving from the atria to the ventricles during ventricular diastole.
IIItone - protodiastolic, because appears at the beginning of diastole immediately after the II tone. It is best heard with direct auscultation at the apex of the heart. It is a weak, low, short sound. It is a sign of good development of the myocardium of the ventricles. With an increase in ventricular myocardial tone in the phase of rapid filling in ventricular diastole, the myocardium begins to oscillate and vibrate. Auscultated through 0.14 -0.20 after the II tone.
IV tone - presystolic, because appears at the end of diastole, precedes the I tone. Very quiet, short sound. It is heard in persons with increased ventricular myocardial tone and is due to fluctuations in the ventricular myocardium when blood enters them in the atrial systole phase. More often heard in a vertical position in athletes and after emotional stress. This is due to the fact that the atria are sensitive to sympathetic influences, therefore, with an increase in the tone of the sympathetic NS, there is some lead in atrial contractions from the ventricles, and therefore the fourth component of the I tone begins to be heard separately from the I tone and is called the IV tone.
FeaturesIandIItones.
I tone is heard louder at the apex and on the tricuspid valve at the base of the xiphoid process at the beginning of systole, that is, after a long pause.
II tone is heard louder at the base - II intercostal space on the right and left at the edge of the sternum after a short pause.
I tone is longer, but lower, duration 0.09-0.12 sec.
II tone is higher, shorter, duration 0.05-0.07 sec.
The tone that coincides with the apex beat and with the pulsation of the carotid artery is tone I, tone II does not match.
I tone does not coincide with the pulse on the peripheral arteries.
Auscultation of the heart is performed at the following points:
the region of the apex of the heart, which is determined by the localization of the apex beat. At this point, a sound vibration is heard that occurs during the operation of the mitral valve;
II intercostal space, to the right of the sternum. Here the aortic valve is heard;
II intercostal space, to the left of the sternum. Here the pulmonary valve is auscultated;
region of the xiphoid process. The tricuspid valve is heard here
point (zone) Botkin-Erbe(III-IV intercostal space 1-1.5 cm lateral (to the left) from the left edge of the sternum. Here, sound vibrations are heard that occur during the operation of the aortic valve, less often - mitral and tricuspid.
During auscultation, the points of maximum sounding of heart tones are determined:
I tone - the area of \u200b\u200bthe apex of the heart (I tone is louder than II)
II tone - the region of the base of the heart.
The sonority of the II tone is compared to the left and right of the sternum.
In healthy children, adolescents, young people of asthenic body type, there is an increase in the II tone on the pulmonary artery (quieter on the right than on the left). With age, there is an increase in the II tone above the aorta (II intercostal space on the right).
On auscultation, analyze sonority heart tones, which depends on the summation effect of extra- and intracardiac factors.
To extracardiac factors include the thickness and elasticity of the chest wall, age, body position, and the intensity of pulmonary ventilation. Sound vibrations are better conducted through a thin elastic chest wall. Elasticity is determined by age. In the vertical position, the sonority of heart tones is greater than in the horizontal position. At the height of inhalation, sonority decreases, while exhalation (as well as during physical and emotional stress) it increases.
Extracardiac factors include pathological processes of extracardiac origin, for example, with a tumor of the posterior mediastinum, with a high standing of the diaphragm (with ascites, in pregnant women, with obesity of the middle type), the heart “presses” more against the anterior chest wall, and the sonority of heart sounds increases.
The sonority of the heart tones is influenced by the degree of airiness of the lung tissue (the size of the air layer between the heart and the chest wall): with increased airiness of the lung tissue, the sonority of the heart tones decreases (with emphysema), with a decrease in the airiness of the lung tissue, the sonority of the heart tones increases (with wrinkling of the lung tissue, surrounding the heart).
With cavity syndrome, heart tones can acquire metallic shades (sonority increases) if the cavity is large and the walls are tense.
The accumulation of fluid in the pleural streak and in the pericardial cavity is accompanied by a decrease in the sonority of heart tones. In the presence of air cavities in the lung, pneumothorax, accumulation of air in the pericardial cavity, an increase in the gas bubble of the stomach and flatulence, the sonority of heart tones increases (due to the resonance of sound vibrations in the air cavity).
To intracardiac factors, which determines the change in the sonority of heart tones in a healthy person and in extracardiac pathology, refers to the type of cardiohemodynamics, which is determined by:
the nature of the neurovegetative regulation of the cardiovascular system as a whole (the ratio of the tone of the sympathetic and parasympathetic divisions of the ANS);
the level of physical and mental activity of a person, the presence of diseases that affect the central and peripheral link of hemodynamics and the nature of its neurovegetative regulation.
Allocate 3 types of hemodynamics:
eukinetic (normokinetic). The tone of the sympathetic division of the ANS and the tone of the parasympathetic division of the ANS are balanced;
hyperkinetic. The tone of the sympathetic division of the ANS predominates. Characterized by an increase in the frequency, strength and speed of contraction of the ventricles, an increase in the speed of blood flow, which is accompanied by an increase in the sonority of heart tones;
hypokinetic. The tone of the parasympathetic division of the ANS predominates. There is a decrease in the sonority of heart tones, which is associated with a decrease in the strength and speed of contraction of the ventricles.
The tone of the ANS changes during the day. During the active time of the day, the tone of the sympathetic division of the ANS increases, and at night - the parasympathetic division.
With heart disease intracardiac factors include:
change in the speed and strength of contractions of the ventricles with a corresponding change in the speed of blood flow;
a change in the speed of movement of the valves, depending not only on the speed and strength of contractions, but also on the elasticity of the valves, their mobility and integrity;
leaf travel distance - distance from ?????? before?????. Depends on the size of the diastolic volume of the ventricles: the larger it is, the shorter the run distance, and vice versa;
the diameter of the valve opening, the condition of the papillary muscles and the vascular wall.
A change in I and II tones is observed with aortic defects, with arrhythmias, with violations of AV conduction.
With aortic insufficiency the sonority of the II tone decreases at the base of the heart and the I tone - at the top of the heart. The decrease in sonority of the second tone is associated with a decrease in the amplitude of the valvular apparatus, which is explained by a defect in the valves, a decrease in their surface area, as well as incomplete closure of the valves at the time of their slamming. Reducing sonorityItones associated with a decrease in valvular oscillations (oscillation - amplitude) of tone I, which is observed with severe dilatation of the left ventricle in aortic insufficiency (the aortic opening expands, relative mitral insufficiency develops). The muscle component of tone I also decreases, which is associated with the absence of a period of isometric tension, because there is no period of complete closure of the valves.
With aortic stenosis a decrease in the sonority of I and II tones in all auscultatory points is associated with a significant decrease in the movement of blood flow, which, in turn, is due to a decrease in the rate of contraction (contractility?) of the ventricles working against the narrowed aortic valve. With atrial fibrillation and bradyarrhythmia, an uneven change in the sonority of tones occurs, associated with a change in the duration of diastole and with a change in the diastolic volume of the ventricle. With an increase in the duration of diastole, blood volume increases, which is accompanied by a decrease in the sonority of heart tones in all auscultatory points.
With bradycardia diastolic overload is observed, therefore, a decrease in the sonority of heart tones in all auscultatory points is characteristic; with tachycardia diastolic volume decreases and the sound rises.
With pathology of the valvular apparatus an isolated change in the sonority of I or II tone is possible.
With stenosis,AVblockadeAVarrhythmias the sonority of the I tone increases.
With mitral stenosis I tone flapping. This is due to an increase in the diastolic volume of the left ventricle, and since. the load falls on the left ventricle, there is a discrepancy between the force of contractions of the left ventricle and the volume of blood. There is an increase in the distance run, tk. BCC decreases.
With a decrease in elasticity (fibrosis, Sanoz), the mobility of the valves decreases, which leads to sonority reductionItones.
With complete AV blockade, which is characterized by a different rhythm of atrial and ventricular contractions, a situation may arise when the atria and ventricles contract simultaneously - in this case, there is sonority increaseItones at the top of the heart - Strazhesko's "cannon" tone.
Isolated sonority attenuationItones observed with organic and relative mitral and tricuspid insufficiency, which is characterized by a change in the cusps of these valves (past rheumatism, endocarditis) - deformation of the cusps, which causes incomplete closure of the mitral and tricuspid valves. As a result, a decrease in the amplitude of the oscillations of the valvular component of the first tone is observed.
With mitral insufficiency, the oscillations of the mitral valve decrease, therefore sonority decreasesItones at the apex of the heart, and with tricuspid - on the basis of the xiphoid process.
Complete destruction of the mitral or tricuspid valve leads to extinctionItones - at the top of the heart,IItones - in the region of the base of the xiphoid process.
Isolated changeIItones in the region of the base of the heart is observed in healthy people, with extracardiac pathology and pathology of the cardiovascular system.
Physiological change II tone ( amplification of sonority) above the pulmonary artery is observed in children, adolescents, young people, especially during physical activity (physiological increase in pressure in the ICC).
In older people amplification of sonorityIIsounds over the aorta associated with an increase in pressure in the BCC with a pronounced compaction of the walls of blood vessels (atherosclerosis).
AccentIIsounds over the pulmonary artery observed in the pathology of external respiration, mitral stenosis, mitral insufficiency, decompensated aortic disease.
Weakening sonorityIItones over the pulmonary artery is determined with tricuspid insufficiency.
Change in the volume of heart sounds. They can occur in amplification or weakening, it can be simultaneously for both tones or in isolation.
Simultaneous weakening of both tones. The reasons:
1. extracardiac:
Excessive development of fat, mammary gland, muscles of the anterior chest wall
Effusive left-sided pericarditis
Emphysema
2. intracardial - a decrease in the contractility of the ventricular myocardium - myocardial dystrophy, myocarditis, myocardiopathy, cardiosclerosis, pericarditis. A sharp decrease in myocardial contractility leads to a sharp weakening of the first tone, in the aorta and LA the volume of incoming blood decreases, which means that the second tone weakens.
Simultaneous volume boost:
Thin chest wall
Wrinkling of lung edges
Increasing the standing of the diaphragm
Volumetric formations in the mediastinum
Inflammatory infiltration of the edges of the lungs adjacent to the heart, as dense tissue conducts sound better.
The presence of air cavities in the lungs located near the heart
An increase in the tone of the sympathetic NS, which leads to an increase in the rate of myocardial contraction and tachycardia - emotional arousal, after heavy physical exertion, thyrotoxicosis, in the initial stage of arterial hypertension.
GainItones.
Mitral stenosis - flapping I tone. The volume of blood at the end of diastole in the left ventricle decreases, which leads to an increase in the rate of myocardial contraction, and the leaflets of the mitral valve thicken.
Tachycardia
Extrasystole
Atrial fibrillation, tachy form
Incomplete AV blockade, when the P-th contraction coincides with the F-s contraction - Strazhesko's cannon tone.
WeakeningItones:
Mitral or tricuspid valve insufficiency. The absence of p-yes closed valves leads to a sharp weakening of the valve and muscle component
Aortic valve insufficiency - more blood enters the ventricles during diastole - increased preload
Stenosis of the aortic orifice - I tone weakens due to severe hypertrophy of the LV myocardium, a decrease in the rate of myocardial contraction due to the presence of increased afterload
Diseases of the heart muscle, accompanied by a decrease in myocardial contractility (myocarditis, dystrophy, cardiosclerosis), but if cardiac output decreases, then II tone also decreases.
If at the top of the I tone in volume it is equal to the II or louder than the II tone - weakening of the I tone. I tone is never analyzed on the basis of the heart.
Volume changeIItones. The pressure in the LA is less than the pressure in the aorta, but the aortic valve is located deeper, so the sound above the vessels is the same in volume. In children and in people under 25 years of age, there is a functional increase (accent) of the II tone over LA. The reason is a more superficial location of the LA valve and a higher elasticity of the aorta, lower pressure in it. With age, blood pressure in the BCC increases; LA moves backward, the accent of the second tone over LA disappears.
Reasons for amplificationIIsounds over the aorta:
Increase in blood pressure
Atherosclerosis of the aorta, due to sclerotic compaction of the valves, an increase in the II tone above the aorta appears - toneBittorf.
Reasons for amplificationIItones over LA- increased pressure in the BCC with mitral heart disease, chronic respiratory diseases, primary pulmonary hypertension.
WeakeningIItones.
Above the aorta: - insufficiency of the aortic valve - the absence of a closing period (?) of the valve
Aortic stenosis - as a result of a slow increase in pressure in the aorta and a decrease in its level, the mobility of the aortic valve decreases.
Extrasystole - due to a shortening of diastole and a small cardiac output of blood into the aorta
Severe arterial hypertension
Reasons for weakeningIItones on LA– insufficiency of LA valves, stenosis of the LA mouth.
Splitting and bifurcation of tones.
In healthy people, there is asynchronism in the work of the right and left ventricles in the heart, normally it does not exceed 0.02 seconds, the ear does not catch this time difference, we hear the work of the right and left ventricles as single tones.
If the time of asynchronism increases, then each tone is perceived not as a single sound. On FKG it is registered within 0.02-0.04 sec. Bifurcation - a more noticeable doubling of tone, asynchronism time 0.05 sec. and more.
The reasons for the bifurcation of tones and splitting are the same, the difference is in time. Functional bifurcation of tone can be heard at the end of exhalation, when intrathoracic pressure rises and blood flow from the ICC vessels to the left atrium increases, resulting in increased blood pressure on the atrial surface of the mitral valve. This slows down its closure, which leads to the auscultation of splitting.
Pathological bifurcation of the I tone occurs as a result of a delay in the excitation of one of the ventricles during the blockade of one of the legs of the His bundle, this leads to a delay in the contraction of one of the ventricles or with ventricular extrasystole. Severe myocardial hypertrophy. One of the ventricles (more often the left - with aortic hypertension, aortic stenosis) myocardium is excited later, more slowly reduced.
BifurcationIItones.
Functional bifurcation is more common than the first, occurs in young people at the end of inhalation or the beginning of exhalation, during exercise. The reason is the non-simultaneous end of the systole of the left and right ventricles. Pathological bifurcation of the II tone is more often noted on the pulmonary artery. The reason is the increase in pressure in the IWC. As a rule, amplification of the II tone on the LH is accompanied by a bifurcation of the II tone on the LA.
Additional tones.
In systole, additional tones appear between I and II tones, this, as a rule, a tone, which is called a systolic click, appears with prolapse (sagging) of the mitral valve due to prolapse of the mitral valve leaflet during systole into the LA cavity - a sign of connective tissue dysplasia. It is often heard in children. The systolic click may be early or late systolic.
In diastole during systole, III pathological tone appears, IV pathological tone and the tone of the opening of the mitral valve. IIIpathological tone occurs after 0.12-0.2 sec. from the beginning of the II tone, that is, at the beginning of diastole. Can be heard at any age. It occurs in the phase of rapid filling of the ventricles in the event that the myocardium of the ventricles has lost its tone, therefore, when the cavity of the ventricle is filled with blood, its muscle easily and quickly stretches, the wall of the ventricle vibrates, and a sound is produced. Auscultated in severe myocardial damage (acute myocardial infections, severe myocarditis, myocardial dystrophy).
PathologicalIVtone occurs before tone I at the end of diastole in the presence of crowded atria and a sharp decrease in ventricular myocardial tone. The rapid stretching of the wall of the ventricles that have lost their tone, when a large volume of blood enters them in the atrial systole phase, causes myocardial fluctuations and an IV pathological tone appears. III and IV tones are heard better at the apex of the heart, on the left side.
gallop rhythm first described by Obraztsov in 1912 - "a cry of the heart for help". It is a sign of a sharp decrease in myocardial tone and a sharp decrease in the contractility of the ventricular myocardium. So named because it resembles the rhythm of a galloping horse. Signs: tachycardia, weakening of I and II tone, the appearance of pathological III or IV tone. Therefore, a protodiastolic (three-part rhythm due to the appearance of the III tone), presystolic (III tone at the end of diastole about the IV pathological tone), mesodiastolic, summative (with severe tachycardia, III and IV tones merge, are heard in the middle of diastole summation III tone).
Mitral valve opening tone- a sign of mitral stenosis, appears after 0.07-0.12 seconds from the beginning of the second tone. With mitral stenosis, the leaflets of the mitral valve are fused together, forming a kind of funnel through which blood from the atria enters the ventricles. When blood flows from the atria into the ventricles, the opening of the mitral valve is accompanied by a strong tension of the valves, which contributes to the appearance of a large number of vibrations that form a sound. Together with a loud, clapping I tone, II tone on the LA forms "quail rhythm" or mitral stenosis melody, best heard at the apex of the heart.
pendulumrhythm- a heart melody is relatively rare, when both phases are balanced due to diastole and the melody resembles the sound of a swinging clock pendulum. In more rare cases, with a significant decrease in myocardial contractility, systole may increase and the pop duration becomes equal to diastole. It is a sign of a sharp decrease in myocardial contractility. Heart rate can be anything. If the pendulum rhythm is accompanied by tachycardia, this indicates embryocardia, that is, the melody resembles the heartbeat of a fetus.
Carrying out auscultation of the heart is usually carried out sequentially: in the supine (on the back), in the standing position of the patient, and also after physical activity (gymnastics). In order for breath sounds not to interfere with listening to sounds of cardiac origin, before listening, it is necessary to invite the patient to inhale, exhale completely and then hold the breath in the exhalation position. This technique is especially important for beginners in the study of auscultation.
Auscultation of the heart is preferable to produce a mediocre way, with a stethoscope. In view of the fact that the individual places of listening to the heart are located at a very close distance from each other, direct auscultation with the ear is used in exceptional cases to supplement the mediocre one. For a correct assessment of auscultation data, it is necessary to know the projection sites of the heart valves on the chest wall and the places of their best listening, since sound vibrations depend not only on the proximity of the valve apparatus, but also on the conduction of these vibrations through the blood flow.
The projection of the valves on the chest:
1. The valve of the pulmonary trunk lies behind the cartilage of the III left rib near the sternum itself and partly behind it;
2. The aortic valve lies behind the sternum directly below and deeper than the opening of the pulmonary trunk;
3. The mitral valve is projected at the site of attachment to the sternum of the cartilage of the IV left rib;
4. The tricuspid valve lies behind the sternum almost in the middle between the places of attachment of the cartilages of the V right and III of the left ribs.
In healthy people, during auscultation of the heart, two tones are well heard: the I tone that occurs during the systole period is systolic, and the II tone that occurs during the diastole period is diastolic.
Beginning clinicians need to accustom themselves to systematically paying attention to all the features of sound phenomena and pauses. The first task is the orienting definition of the first tone, since the sound cycle of cardiac contraction begins with it. Then, in sequential order, all four holes of the heart are heard.
Listening locations:
The mitral valve tone is heard most clearly at the apex of the heart (1.5 - 2.0 cm medially from the left midclavicular line), the pulmonary artery valve - in the II left intercostal space at the edge of the sternum, the aortic tone - at the edge of the sternum in the II right intercostal space, tricuspid valve - at the base of the xiphoid process of the sternum; the aortic valve is also auscultated at the site of attachment of the III-IV ribs - the Botkin-Erb point (V auscultation point). Listening to the valves is carried out in the indicated sequence, corresponding to the decreasing frequency of their defeat.
For each researcher, it is necessary to determine:
1. strength or clarity of tones;
2. timbre of tones;
3. frequency,
5. presence or absence of noise.
When listening to a healthy heart, two tones are heard, periodically replacing each other. Starting auscultation of the heart from the top, we hear:
1. short, stronger sound - first tone,
2. short first pause,
3. weaker and even shorter sound - second tone
4. second pause, twice as long as the first.
The first tone, unlike the second, is somewhat longer, lower in tone, stronger at the top, weaker at the base, and coincides with the apex beat. It is more convenient for beginners to distinguish the first tone from the second, focusing on a short pause, that is, guided by the fact that the first tone is heard before it, or, in other words, a short pause follows the first tone. In the case of a frequent heart rhythm, when it is not possible to clearly differentiate the tones, it is necessary, while listening, to attach the fingers of the right hand to the place of the apex beat (or to the carotid artery on the neck). The tone coinciding with the push (or with the pulse on the carotid artery) will be the first. It is impossible to determine the first tone by the pulse on the radial artery, since the latter is late in relation to the first heart sound.
First tone It is made up of 4 main components:
1. Atrial component- associated with fluctuations in the atrial myocardium. Atrial systole precedes ventricular systole, so normally this component merges with the first tone, forming its initial phase.
2. Valve component- fluctuation of the leaflets of atrioventricular valves in the contraction phase. The amount of oscillation of the leaflets of these valves is affected by intraventricular pressure, which in turn depends on the rate of contraction of the ventricles.
3. Muscular component - also occurs during the contraction of the ventricles and is due to myocardial fluctuations.
4. Vascular component- It is formed due to fluctuations in the initial sections of the aorta and pulmonary trunk during the period of expulsion of blood from the heart.
second tone,
arising at the beginning of diastole, is formed by 2 main components:
1. Valve component- slamming of the cusps of the aortic and pulmonary valves.
2. Vascular component- fluctuation of the walls of the aorta and pulmonary trunk.
Third tone due to fluctuations that appear with the rapid relaxation of the ventricles, under the influence of blood flow, pouring out of the atria. This tone can be heard in healthy people, mainly in young people and adolescents. It is perceived as a weak, low and muffled sound at the beginning of diastole after 0.12-0.15 s from the beginning of the second tone.
fourth tone precedes the first tone and depends on the fluctuations that occur during atrial contraction. For children and adolescents, it is considered physiological, its appearance in adults is pathological.
The third and fourth tones are heard better with direct auscultation, they are clearly identified when registering a phonocardiogram. The detection of these tones in the elderly, as a rule, indicates severe myocardial damage.
Changes in heart sounds
Muting both tones, observed with a decrease in the contractility of the heart muscle, can be both under the influence of extracardiac causes (excessive subcutaneous fat, anasarca, significant development of the mammary glands in women, pronounced development of the muscles of the chest, emphysema, accumulation of fluid in the cavity of the heart bag: and also as a result of lesions of the heart itself (myocarditis, cardiosclerosis, due to decompensation in various heart diseases).
Strengthening both tones of the heart depends on a number of extracardiac causes (thin chest, retraction of the pulmonary margins, tumors of the posterior mediastinum) and can be observed with thyrotoxicosis, fever and some intoxications, for example, caffeine.
More often there is a change in one of the tones, which is especially important in the diagnosis of heart disease.
Weakening of the first tone at the apex of the heart is observed with mitral and aortic valve insufficiency (due to the absence of a period of closed valves during systole), with narrowing of the aortic orifice and with diffuse myocardial lesions (due to dystrophy, cardiosclerosis, myocarditis) with myocardial infarction.
In case of insufficiency of the tricuspid valve and the valve of the pulmonary trunk, the weakening of the first tone is observed at the base of the xiphoid process due to the weakening of the muscular and valvular components of these valves. Weakened first sound on the aorta is one of the characteristic acoustic signs of insufficiency of the aortic semilunar valve. This occurs due to an increase in intraventricular pressure above the level of the left atrial at the end of diastole, which contributes to an earlier closure of the mitral valve and limits the amplitude of movement of its valves.
Amplification of the first tone(clapping tone) at the apex of the heart is observed with a decrease in the filling of the left ventricle with blood during diastole and is one of the characteristic signs of stenosis of the left atrioventricular orifice. The reason for its strengthening is the compaction of the leaflets of the mitral valve due to their fibrotic changes. These structural features of the valve determine the change in the frequency-amplitude characteristics of the first tone. Dense tissues are known to generate higher frequency sounds. The first tone ("Strazhesko's cannon tone") is especially loud with complete atrioventricular blockade of the heart, when there is a simultaneous contraction of the atria and ventricles. Strengthening of the first tone at the base of the xiphoid process is observed with stenosis of the right atrioventricular orifice; it can also be observed with tachycardia and extrasystole.
Weakening of the second tone above the aortic valve is observed with its insufficiency or due to partial or complete destruction of the aortic valve cusps (in the second case, the II tone may be completely absent), or with their cicatricial compaction. The weakening of the second tone on the pulmonary artery is noted with insufficiency of its valve (which is extremely rare) and with a decrease in pressure in the pulmonary circulation.
Amplification of the second tone on the aorta is observed with an increase in pressure in the systemic circulation in diseases accompanied by arterial hypertension (hypertension, glomerulonephritis, polycystic kidney disease, etc.). A sharply increased second tone (clangor) is observed in syphilitic mesaortitis. Strengthening of the second tone on the pulmonary artery is ascertained with an increase in pressure in the pulmonary circulation (mitral heart disease), difficulty in blood circulation in the lungs (pulmonary emphysema, pneumosclerosis). If this tone is louder over the aorta, they talk about the accent of the second tone on the aorta, if it is louder over the pulmonary trunk, they talk about the accent of the II tone on the pulmonary artery.
Bifurcation of heart sounds.
Heart sounds, terms t several components are perceived as a single sound. Under some physiological and pathological conditions, there is no synchronism in the sound of those components that take part in the formation of a particular tone. There is a split tone.
Bifurcation of tones is the selection of the components that make up the tone. The latter follow each other at short intervals (after 0.036 s or more). The mechanism of bifurcation of tones is due to asynchronism in the activity of the right and left halves of the heart: non-simultaneous closing of the atrioventricular valves leads to a bifurcation of the first tone, semilunar valves - to a bifurcation of the second tone. Bifurcation of tones can be physiological and pathological. Physiological bifurcation (splitting) of I tone occurs when the atrioventricular valves close asynchronously. This can be during a deep exhalation, when, due to an increase in pressure in the pulmonary circulation, blood enters the left atrium with greater force and prevents the mitral valve from closing in time.
Physiological split II tone It manifests itself in connection with various phases of respiration, since when inhaling and exhaling, the blood filling of the left and right ventricles changes, and, consequently, the duration of their systole and the closing time of the corresponding valves. The bifurcation of the second tone is especially well detected during auscultation of the pulmonary artery. Physiological bifurcation of the II tone is not permanent (non-fixed bifurcation), is closely related to the normal mechanism of respiration (it decreases or disappears during inspiration), while the interval between the aortic and pulmonary components is 0.04-0. Obs.
Pathological bifurcation of tones may be due to the following factors:
1. Hemodynamic (increase in systolic volume of one of the ventricles, increase in diastolic pressure in one of the ventricles, increase in diastolic pressure in one of the vessels);
2. Violation of intraventricular conduction (blockade of the legs of the bundle of His);
3. Weakening of the contractile function of the myocardium;
4. Ventricular extrasystole.
Pathological bifurcation of the I tone may be in violation of intraventricular conduction (along the legs of the bundle of His) due to a delay in the next contraction of one of the ventricles.
Pathological bifurcation II tone is observed with arterial hypertension, with stenosis of the aortic orifice, when the aortic valve flaps slam shut later than the pulmonary valve; in the case of an increase in pressure in the pulmonary circulation (with emphysema, mitral stenosis, etc.), when, on the contrary, the pulmonary valve lags behind.
From bifurcation of tones it is necessary to distinguish the appearance additional tones.
These include mitral valve opening tone, auscultated during narrowing of the left atrioventricular orifice. The mechanism of its occurrence is associated with a sudden tension of sclerosed valve cusps, unable to move completely to the walls of the ventricle during the passage of blood from the left atrium to the left ventricle. The tone of the mitral valve opening occurs immediately after the II tone after 0.07-0.13s, during the diastole period. It is best heard at the apex, combined with other auscultatory signs of mitral stenosis. In general, an additional third mitral valve opening sound, combined with a loud (clapping) first heart sound and a second heart sound, form a three-term rhythm resembling a quail cry, - quail rhythm.
The three-term rhythm also includes rhythm gallop reminiscent of the tramp of a galloping horse. There are presystolic gallop rhythm, which is caused by a pathological IV heart sound and a summation gallop rhythm, the occurrence of which is associated with the imposition of III and IV tones; an additional tone with this rhythm is usually heard in the middle of diastole. A gallop rhythm is heard in severe myocardial damage (myocardial infarction, myocarditis, chronic nephritis, hypertension, etc.).
With severe tachycardia, there is a shortening of the diastolic pause to the size of the systolic one. At the top of I and II, the tones become almost identical in sonority, which served as the basis for calling such an auscultatory picture pendulum rhythm or, similar to the fetal heartbeat, embryocardia. This can be observed in acute heart failure, paroxysmal tachycardia, high fever, etc.
Heart murmurs
Noises can occur both inside the heart (intracardiac) and outside it (extracardiac).
The main mechanisms for the formation of intracardiac murmurs are changes in the size of the openings of the heart and changes in the speed of blood flow. Their occurrence may depend on the rheological properties of the blood, and sometimes on the irregularities of the endocardial valves, as well as the state of the intima of the vessels.
Intracardiac murmurs are classified into organic, which are caused by anatomical changes in the openings and valve apparatus (acquired and congenital malformations) and inorganic or functional, arising from anatomically intact valves and associated with changes in the activity of the heart, with a decrease in blood viscosity
An intermediate position between organic and functional murmurs is occupied by murmurs of relative muscular insufficiency of valves. Relative valve insufficiency noise occurs during dilatation of the ventricles, and, consequently, the expansion of the atrioventricular orifice, and therefore even an unchanged valve cannot completely close it. With improvement in myocardial contractility, the noise may disappear. A similar mechanism occurs in violation of the tone of the papillary muscles.
According to the time of appearance of the noise in relation to the phases of cardiac activity, systolic and diastolic heart murmurs are distinguished.
Systolic murmurs are heard between I and D tones (in a short pause), and diastolic murmurs - between P and the next I tone (in a long pause). Noise can occupy the entire pause or only part of it. By hemodynamic origin, ejection murmurs and regurgitation murmurs are distinguished.
Systolic murmurs can be organic and functional, and are usually stronger than diastolic murmurs in intensity.
Systolic murmur It occurs when blood meets an obstacle in its path. It is divided into two main types:
1. Systolic ejection murmur(with stenosis of the mouth of the aorta or pulmonary trunk: since during the expulsion of blood from the ventricles, a narrowing of the vessel occurs on the path of blood flow);
2. Systolic murmur of regurgitation(with insufficiency of the mitral or tricuspid valves; in these cases, in the systole of the ventricles, the blood goes not only to the aorta and pulmonary trunk, but also back to the atria through an incompletely covered atrioventricular opening.) Diastolic murmur occurs either with stenosis of the atrioventricular openings, because during diastole there is a narrowing in the path of blood flow from the atria to the ventricles, or in case of insufficiency of the aortic valve or pulmonary valve - due to the reverse flow of blood from the vessels to the ventricles in the diastole phase.
According to their properties, noises are distinguished:
1. by timbre (soft, blowing; or rough, scraping, sawing);
2. by duration (short and long),
3. by volume (quiet and loud);
4. by intensity in dynamics (decreasing or increasing noise);
PLACES OF THE BEST LISTENING AND NOISE CONDUCTIVITY:
Noises are heard not only in the classical places of listening to tones, but also at some distance from them, especially along the path of blood flow. With aortic stenosis the murmur is conducted into the carotid and other major arteries and is even heard on the back at the level of I-III thoracic vertebrae. Murmur of aortic valve insufficiency carried out, on the contrary, to the ventricle, i.e. to the left down, and the place of listening passes along this line to the sternum, to its left edge, at the place of attachment of the third costal cartilage. In the initial stages of damage to the aortic valves, for example, with rheumatic endocarditis, a gentle diastolic murmur, as a rule, is not heard in the usual place (the second intercostal space on the right), but only at the left edge of the sternum in the third or fourth intercostal space - at the so-called fifth point. Noise due to bicuspid valve insufficiency carried up to the second intercostal space or to the left to the armpit. With ventricular septal insufficiency the noise spreads across the sternum from left to right.
All conduction noises lose strength in proportion to the square of the distance; this circumstance helps to understand their localization. In the presence of mitral valve insufficiency and stenosis of the aortic orifice, we, going from the top along the line connecting the places of their listening, will first hear a decreasing noise of moral insufficiency, and then an increasing noise of aortic stenosis. Only presystolic noise at a mitral stenosis has very small scope of distribution; sometimes it is auscultated in a very limited area.
Systolic murmurs of aortic origin (narrowing of the mouth, irregularities of the aortic wall, etc.) are well heard in the suprasternal fossa. With a significant expansion of the left atrium, the systolic murmur of mitral insufficiency is sometimes heard to the left of the spine at the level of the VI-VII thoracic vertebrae.
diastolic murmurs ,
depending on which part of the diastode occurs, they are divided into protodiastolic (at the beginning of the diastole, Greek protos - the first), mesodiastolic (occupying only the middle of the diastole, Greek mesos - middle) and presystolic or telediastolic (at the end of the diastole, increasing to noise of the first tone, Greek telos - end). The vast majority of diastolic murmurs are organic. Only in some cases they can be heard without the presence of organic damage to the valves and orifices.
Functional diastolic murmurs.
There are functional presystolic flint noise when, in aortic valve insufficiency, the reverse wave of blood lifts the leaflet of the moral valve, narrowing the left atrioventricular orifice, thereby creating relative mitral stenosis. mesodiastolic Coombs noise may occur at the beginning of an attack of rheumatism due to edema of the left atrioventricular orifice and the occurrence of its relative stenosis. When removing the exudative phase, the noise may disappear. Graham-Still noise can be determined in diastole over the pulmonary artery, when stagnation in the small circle causes stretching and expansion of the pulmonary artery, and therefore there is a relative insufficiency of its valve.
In the presence of noise, it is necessary to determine its relation to the phases of cardiac activity (systolic or diastolic), to clarify the place of its best listening (epicenter), conductivity, strength, variability and character.
Characteristics of murmurs in some heart defects.
mitral valve insufficiency characterized by the presence of a systolic murmur at the apex of the heart, which is heard along with a weakened I tone or instead of it, decreases towards the end of systole, is quite sharp, rough, well conducted into the armpit, better heard in the position of the patient on the left side.
At stenosis of the left atrioventricular orifice the noise occurs in the mesodiastole, is of an increasing nature (crescendo) is heard at the apex, is not conducted anywhere. Often ends with a clapping I tone. It is better defined in the position of the patient on the left side. Presystolic noise, clapping I tone and "double" II-nd give a typical melody of mitral stenosis.
At aortic valve insufficiency diastolic murmur begins immediately after tone II, in protodiastole, gradually decreasing towards its end (decrescendo), better heard at point 5, less pronounced in the 2nd intercostal space to the right of the sternum, carried out at the apex of the heart, the murmur is soft, better heard during breath holding after deep breath. It is best heard in the patient's standing position, especially when the torso is tilted forward.
In cases aortic stenosis systolic murmur is heard in the second intercostal space on the right at the edge of the sternum. It is very sharp, rough, muffles the I tone, is auscultated throughout the systole and is most conductive, well auscultated on the vessels of the neck, on the back along the spine.
At tricuspid valve insufficiency The maximum sound of the noise is determined at the base of the xiphoid process of the sternum. With organic valve damage, the systolic murmur is rough, clear, and with relative valve insufficiency, it is softer, blowing.
Of the rarer defects, in which systolic murmur is determined, indicate stenosis of the orifice of the pulmonary artery(the maximum of its sounding is in the second intercostal space to the left of the sternum, it is carried out to the left collarbone and to the left half of the neck); cleft of the Botallian duct(systole-diastolic murmur in 3-4 intercostal spaces); ventricular septal defect(in the 4th intercostal space, somewhat outward from the left edge of the sternum, it is carried out in the form of "wheel spokes" - from the epicenter of the noise in a circle, loud, sharp in timbre).
Extracardiac (extracardiac) murmurs.
Noises can occur not only inside the heart, but also outside it, synchronously with heart contractions. Distinguish between pericardial murmur or pericardial friction murmur and pleuropericardial friction murmur.
Pericardial murmur it is heard mainly due to inflammatory phenomena in the pericardium, in myocardial infarction, in tuberculosis with fibrin deposition, etc. Pericardial friction noise is characterized by:
1. It is either barely perceptible, or very rough, with direct auscultation sometimes even causes discomfort, as it is heard directly under the ear,
2. Noise is associated with the phases of cardiac activity, but not exactly: it goes from systole to diastole and vice versa (in systole it is usually stronger);
3. Almost never radiates,
4. Variable in location and time;
5. When leaning forward, when standing on all fours, and when pressing with a stethoscope, the noise increases.
Along with pericardial murmur, false pericardial (pleuropericardial) friction murmur is distinguished, associated with dry pleurisy of parts of the pleura adjacent to the heart, mainly on the left. Contractions of the heart, increasing the contact of the pericardium and pleura, contribute to the appearance of friction noise. The difference from the true pericardial murmur is that it is heard only with deep breathing, intensified during inspiration and localized mainly at the left edge of the heart.
Cardiopulmonary murmurs arise to the parts of the lungs adjacent to the heart, straightening out during systole due to a decrease in the volume of the heart. Air, penetrating into this part of the lungs, gives a vesicular noise in nature ("vesicular breathing") and systolic in time.
Auscultation of arteries and veins.
In a healthy person, you can listen to tones on medium-sized arteries (carotid, subclavian, femoral, etc.). As in the heart, two tones are often heard on them. The arteries are preliminarily palpated, then a stethoscope funnel is attached, trying not to compress the vessel, avoiding the occurrence of stenotic noise.
Normally, two tones (systolic and diastolic) are heard on the carotid and subclavian arteries. On the femoral artery, only the first, systolic tone can be heard. In both cases, the first tone is partially wired, partially formed at the site of auscultation. The second tone is completely conducted from the semilunar valves.
The carotid artery is heard at the level of the larynx from the inside m. Stemo-cleido-mastoidei, and subclavian - on its outer side, immediately above the clavicle or below the clavicle in its outer third. Listening to other arteries does not give tones.
In case of aortic valve insufficiency with a pronounced fast pulse (pulsus celer), tones can also be heard above the arteries, where they are usually not heard - above the abdominal aorta, brachial, radial arteries. Over the femoral artery with this defect, two tones are sometimes heard ( Traube double tone), due to sharp fluctuations of the vascular wall both in the phase of systole and in diastole. In addition, tones in the peripheral arteries can occur with pronounced left ventricular hypertrophy and thyrotoxicosis due to increased vascular pulsation.
Noises can also be heard above the arteries. This is observed in the following cases:
1. Wired blood flow in aortic stenosis, atherosclerosis with intima changes and aneurysms;
2. Systolic, associated with a decrease in blood viscosity and an increase in blood flow velocity (with anemia, fever, thyrotoxicosis;
3. Local - when the artery is compressed from the outside (for example, by pleural stitches around the subclavian artery), its sclerotic stenosis, or, conversely, with its aneurysm;
4. in case of insufficiency of the aortic valve on the femoral artery with a slight compression of it, it is heard double Vinogradov-Durozier noise, in the first phase caused by a squeezed stethoscope, in the second, probably by a reverse flow of blood.
When listening to the veins, they use exclusively auscultation of the bulb of the jugular vein above the clavicle, more often on the right. The stethoscope must be placed very carefully to avoid compression noise. With a decrease in blood viscosity, due to an increase in blood flow in patients with anemia, noise is heard here, continuously, almost regardless of heart contractions. By nature it is musical and low and is called "the noise of the top". This noise is heard better when turning the head in the opposite direction. This noise has no particular diagnostic value, especially since it can rarely be observed in healthy people.
In conclusion, it should be noted that in order to hear the heart, one must learn to listen to it. First, it is necessary to repeatedly listen to healthy people with a slow heart rate, then with tachycardia, then with atrial fibrillation, setting ourselves the task of distinguishing tones. Gradually, as experience is gained, the analytical method of studying the heart melody must be replaced by a synthetic one, when the totality of the sound symptoms of one or the other. another defect is perceived as a whole, which speeds up the diagnostic process. However, in complex cases, one should try to combine these two approaches to the study of acoustic phenomena of the heart. For novice doctors, a detailed verbal description of the heart melody of each patient, produced in a certain sequence, repeating the sequence of auscultation, is considered very useful. The description should include a description of the heart sounds at all listening points, as well as the main properties of the noise. It is advisable to use the graphical representation of the heart melody used in clinics. Both of these methods are aimed at cultivating the habit of systematic auscultation.
Self-education of auscultation should be practiced stubbornly, without being upset by the inevitable failures at first. It should be remembered that "the period of learning auscultation lasts a lifetime."
Heart sounds a sound manifestation of the mechanical activity of the heart, determined by auscultation as alternating short (percussion) sounds, which are in a certain connection with the phases of systole and diastole of the heart. T. s. are formed in connection with the movements of the valves of the heart, chords, cardiac and vascular walls, generating sound vibrations. The listened loudness of tones is determined by the amplitude and frequency of these oscillations (see Auscultation) .
Graphic registration T. with. with the help of phonocardiography showed that, in terms of its physical nature, T. s. are noises, and they are like tones due to the short duration and rapid damping of aperiodic oscillations. Most researchers distinguish 4 normal (physiological) T. s., of which I and II tones are always heard, and III and IV are not always determined, more often graphically than during auscultation ( rice.
). I tone is heard as quite intense over the entire surface of the heart. It is maximally expressed in the region of the apex of the heart and in the projection of the mitral valve. The main fluctuations of the I tone are associated with the closure of the atrioventricular valves; participate in its formation and movements of other structures of the heart. On FCG, as part of tone I, initial low-amplitude low-frequency oscillations associated with contraction of the muscles of the ventricles are distinguished; the main, or central, I tone, consisting of oscillations of large amplitude and higher frequency (arising from the closure of the mitral and tricuspid valves); the final part - low-amplitude oscillations associated with the opening and oscillation of the walls of the semilunar valves of the aorta and pulmonary trunk. The total duration of the I tone ranges from 0.7 to 0.25 With. At the apex of the heart, the amplitude of the I tone is 1 1/2 -2 times greater than the amplitude of the II tone. The weakening of the I tone may be associated with a decrease in the contractile function of the heart muscle in myocardial infarction, myocarditis, but it is especially pronounced with mitral valve insufficiency (may not be heard, being replaced by systolic murmur). Flapping I tone (increase in both amplitude and frequency of oscillations) is most often determined with mitral stenosis, when it is caused by compaction of the mitral valve cusps and shortening of their free edge while maintaining mobility. A very loud ("cannon") I tone occurs with complete atrioventricular block (see Heart block) at the time of coincidence in systole time, regardless of the contracting atria and ventricles of the heart. II tone is also auscultated over the entire region of the heart, as much as possible - at the base of the heart: in the second intercostal space to the right and left of the sternum, where its intensity is greater than the first tone. The origin of the II tone is mainly associated with the closure of the valves of the aorta and pulmonary trunk. It also includes low-amplitude low-frequency oscillations resulting from the opening of the mitral and tricuspid valves. On FCG, the first (aortic) and second (pulmonary) components are distinguished as part of the II tone. The amplitude of the first component is 1 1/2 -2 times greater than the amplitude of the second. The interval between them can reach 0.06 With which is perceived during auscultation as the second tone. It can be given with physiological asynchronism of the left and right halves of the heart, which is most common in children. An important characteristic of the physiological splitting of the II tone is its phases of respiration (non-fixed splitting). The basis of the pathological or fixed, splitting of the II tone with a change in the ratio of the aortic and pulmonary components can be an increase in the duration of the phase of expulsion of blood from the ventricles and a slowdown in intraventricular conduction. The volume of the II tone during its auscultation over the aorta and pulmonary trunk is approximately the same; if it prevails over any of these vessels, they speak of an accent of the II tone over this vessel. The weakening of the second tone is most often associated with the destruction of the aortic valve cusps in case of its insufficiency or with a sharp limitation of their mobility in severe aortic stenosis. Strengthening, as well as an accent of the II tone over the aorta, occurs with arterial hypertension in the systemic circulation (see Arterial hypertension) ,
above the pulmonary trunk - with hypertension of the pulmonary circulation (Hypertension of the pulmonary circulation) .
Ill tone - low-frequency - is perceived during auscultation as a weak, dull sound. On FKG it is determined on a low-frequency channel, more often in children and athletes. In most cases, it is recorded at the apex of the heart, and its origin is associated with fluctuations in the muscular wall of the ventricles due to their stretching at the time of rapid diastolic filling. Phonocardiographically, in some cases, a left and right ventricular III tone is distinguished. The interval between II and left ventricular tone is 0.12-15 With. The so-called mitral valve opening tone is distinguished from the III tone - a sign of mitral stenosis. The presence of the second tone creates an auscultatory picture of the “quail rhythm”. III tone appears with heart failure (Heart failure) and causes proto- or mesodiastolic (see Gallop rhythm) .
Ill tone is better heard with a stethoscopic head of a stethophonendoscope or by direct auscultation of the heart with an ear tightly attached to the chest wall. IV tone - atrial - is associated with atrial contraction. With synchronous recording, c is recorded at the end of the P wave. This is a weak, rarely heard tone, recorded on the low-frequency channel of the phonocardiograph, mainly in children and athletes. Pathologically enhanced IV tone causes a presystolic gallop rhythm during auscultation. The fusion of III and IV pathological tones in tachycardia is defined as "summation gallop". A number of additional systolic and diastolic tones (clicks) are determined with Pericarditis e ,
pleuropericardial adhesions ,
mitral valve prolapse. Bibliography: Kassirsky G.I. with congenital and acquired heart defects, Tashkent 1972, bibliogr.; Solovyov V.V. and Kassirsky G.I. Atlas of clinical phonocardiography, M., 1983; Fitileva L. M. Clinical, M., 1968; Holldak K. and Wolf D. Atlas and guide to phonocardiography and related mechanocardiographic research methods, with German, M., 1964. heart sounds; a - the initial component of the I tone, b - the central segment of the I tone; c - the final component of the I tone; A - aortic component of the II tone; P - pulmonary component of the II tone "\u003e Schematic representation of synchronously recorded phonocardiograms (below) and electrocardiograms (above) are normal: I, II, III, IV - corresponding heart sounds; a - the initial component of the I tone, b - the central segment of the I tone; c - the final component of the I tone; A - aortic component of the II tone; P - pulmonary component of the II tone.
1. Small medical encyclopedia. - M.: Medical Encyclopedia. 1991-96 2. First aid. - M.: Great Russian Encyclopedia. 1994 3. Encyclopedic dictionary of medical terms. - M.: Soviet Encyclopedia. - 1982-1984.
See what "Heart sounds" are in other dictionaries:
HEART TONES- heart sounds, sounds that occur during the work of the heart. Normally, during auscultation of the heart in animals, two clear constant tones are heard - the first and second. The first (systolic) tone occurs during systole when the atrio collapses ... ...
Heart sounds- (soni cordis, from lat. sonus sound, tone + cor, cordis heart) - sounds with a frequency of up to 1000 Hz; occur during the work of the heart; registered on the surface of the chest wall; 5 tones were set: 1st systolic, 2nd diastolic, 3rd ventricular, 4 ... Glossary of terms for the physiology of farm animals
See Heart ... - I Cardiac tamponade (synonymous with tamponade of the pericardial cavity) is a violation of cardiac activity and systemic hemodynamics caused by compression of the heart by fluid that has entered the pericardial cavity. It develops due to an increase in pressure in the cavity ... ... Medical Encyclopedia
Or heart sounds are caused by the slamming of the heart and arterial valves. See Heart for details. The significance of these tones in medicine is great, since with a change in the valves, with their defeat, the nature of Sh. of the heart also changes. Thus, according to ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron
EXPANSION OF THE HEART- (Dilatatio cordis), an increase in the cavities of the heart. It occurs as a complication of various myocardial diseases, as well as with nephritis, alveolar emphysema. Cardiac impulse is strengthened (rarely weakened), diffuse, short. The pulse is small, weak filling ... Veterinary Encyclopedic Dictionary
HEART BLOCK- (heart block; the unfortunate name “block” should be left), a break in excitation running through the heart from its sinus node up to the terminal branches of the atrioventricular bundle (see) His Tawara (His Ta wara) so-called ... ...
HEART ARRHYTHMIAS- HEART ARRHYTHMIAS. Contents: Sinus Rhythm Disturbances Tachycardia ................. 216 Bradycardia .................. 217 Sinus arrhythmias .............. ....... 217 Extrasystolic arrhythmia ......... 218 Arhythmia perpetua .............. 224 ... ... Big Medical Encyclopedia
Lecture number 10.
Auscultation of the heart. Heart sounds in norm and pathology.
Listening (auscultation) of sound phenomena formed during the work of the heart is usually performed using a stethophonendoscope. This method has a great advantage over direct listening, since it makes it possible to clearly localize various sounds and, thanks to this, determine places from the formation.
Listening to the patient should be carried out in a warm room and with a warm instrument. When working in a cold room or with a cold tool, the patient develops muscle tremors. In this case, a lot of side sounds arise, which greatly complicate the assessment of the auscultatory picture. Listening to the patient is carried out with his calm breathing. However, in many situations, when the doctor picks up weak sound phenomena, he asks the patient to hold his breath in the phase of maximum exhalation. At the same time, the volume of the air-containing lungs around the heart decreases, the respiratory noises that occur in the lungs disappear, and the sound picture of the beating heart is perceived more easily.
In what position of the body should the patient be listened to? It all depends on the auscultatory picture and the patient's condition. Usually, auscultation is carried out in the vertical position of the patient's body (standing, sitting) or lying on his back. However, many sound phenomena, such as a pericardial friction rub, are better heard when the patient is tilted forward or in a position on the left side, when the heart is closer to the anterior chest wall. If necessary, auscultation is carried out with a deep breath with straining (Valsalva test). In many cases, cardiac auscultation is repeated after physical exertion. For this, the patient is asked to sit or lie down, do 10-15 sit-ups, etc.
Along with listening to the sound phenomena that occur during the work of the heart, the phonocardiography technique is currently widely used. Phonocardiography is a graphic recording on a paper tape of sound phenomena that occur during the work of the heart, perceived by a sensitive microphone. Sound phenomena are depicted as oscillations of various amplitudes and frequencies. Simultaneously with the recording of sound phenomena, an electrocardiogram is recorded in one standard lead, usually in the second. This is necessary to determine in which phase of cardiac activity the recorded sound occurs. Currently, phonocardiography involves recording sounds in 3 to 5 different sound frequency ranges. It allows you to document not only the very fact of the presence of a particular sound, but also its frequency, shape, amplitude (loudness). With the undoubted diagnostic value of the technique, it should be taken into account that the sound picture perceived by ear sometimes turns out to be more informative than the graphically recorded one. In some situations, during phonocardiography, the sound energy is distributed over 3-5 recorded channels and is encrypted as background, while a clear, diagnostically significant sound picture is determined by ear. Therefore, phonocardiography, of course, should be attributed to a valuable, but additional research method.
When listening to the heart, tones and noises are distinguished. According to scientific terminology, those sound phenomena that are commonly called tones do not deserve this name, because. they, like heart murmurs, are produced by irregular, aperiodic sound vibrations (the intervals between vibrations of each tone are not equal). In this sense, even many heart murmurs (the so-called musical ones) are much closer to real tones.
Normally, physiologically, 2 tones are heard over the heart. Of these, in time, the 1st corresponds to the beginning of ventricular systole - the period of closed valves. It is called the systolic tone. The second corresponds in time to the very beginning of the diastole of the heart and is called diastolic.
Origin of the first tone complex. The formation of 1 heart sound begins at the very beginning of the systole of the heart. As you know, it begins with atrial systole, pushing the blood remaining in them into the ventricles of the heart. This component is 1 tone, atrial, quiet, low-amplitude on the phonocardiogram, short. If our ear could perceive separately sounds very close to each other, we would listen to a separate weak atrial tone and a stronger tone, which is formed in the phase of ventricular systole. But under physiological conditions, we perceive the atrial component of the 1st tone together with the ventricular one. In pathological conditions, when the time of atrial and ventricular systole are spaced more than usual, we listen to the atrial and ventricular components of the 1st tone separately.
In the phase of asynchronous contraction of the heart, the process of excitation of the ventricles, the pressure in which is still close to "0", the process of contraction of the ventricles covers all myocardial fibers and the pressure in them begins to increase rapidly. At this time, a long-term ventricular or muscle component of tone 1. The ventricles of the heart at this moment of the systole of the heart are 2 completely closed bags, the walls of which are tensed around the blood they contain and, due to this, come into oscillation. All parts of the walls vibrate, and they all give tone. From this it is clear that the complete closure of the ventricles of the heart from all sides is the main condition for the formation of the first tone.
The main loudness component of the 1st tone falls at the moment when the two- and three-leaf valves of the heart slam shut. These valves have closed, but the semilunar valves have not yet opened. The tone of that part of the walls that is most capable of vibrating, namely the tone of thin elastic flap valves, valve component 1 tone, will be dominant in volume. With significant valve insufficiency, the tone of the corresponding ventricle will completely disappear by ear.
The first tone is not only conducted from the ventricles and cuspid valves, but also occurs due to sudden tension and vibration of the walls of the aorta and pulmonary artery when the blood of their ventricles enters them. This component 1 vascular. Since this occurs already in the phase of the beginning of emptying of the ventricles, the first tone also captures the period of the beginning of the expulsion of blood from the ventricles.
So, 1 heart sound consists of 4 components - atrial, muscular, valvular and vascular.
The period of expulsion of blood from the ventricles of the heart consists of two phases - fast and slow expulsion of blood. At the end of the slow ejection phase, the ventricular myocardium begins to relax, and its diastole begins. The blood pressure in the ventricles of the heart decreases, and blood from the aorta and from the pulmonary artery rushes back into the ventricles of the heart. It closes the semilunar valves and arises second or diastolic heart sound. The first tone is separated from the second tone by a small pause, with an average duration of about 0.2 seconds. The second tone has two components, or two constituents. The main loudness is valve the component formed by the vibrations of the semilunar valve cusps. After the slamming of the semilunar valves, the blood rushes into the arteries of the systemic and pulmonary circulation. The pressure in the aorta and pulmonary trunk gradually decreases. All pressure drops and blood movement in the aorta and pulmonary artery are accompanied by vibrations of their walls, forming a second, less loud, component of 2 tones - vascular component.
The time from the onset of ventricular relaxation to the closing of the semilunar valves is called proto-diastolic period equal to 0.04 seconds. The blood pressure in the ventricles at this time drops to zero. The flap valves are still closed at this time, the volume of blood remaining in the ventricles, the length of the myocardial fibers have not yet changed. This period is called a period of isometric relaxation equal to 0.08 seconds. By its end, the cavities of the ventricles of the heart begin to expand, the pressure in them becomes negative, lower than in the atria. The cusp valves open, and blood begins to flow from the atria into the ventricles of the heart. Begins period of filling of the ventricles with blood, lasting 0.25 seconds. This period is divided into 2 phases of fast (0.08 seconds) and slow (0.17 seconds) filling of the ventricles with blood.
At the beginning of the rapid flow of blood into the ventricles, due to the impact of the incoming blood on their walls, third heart sound. It is deaf, best heard over the apex of the heart in the position of the patient on the left side and follows at the beginning of diastole approximately 0.18 seconds after 2 tones.
At the end of the phase of slow filling of the ventricles with blood, in the so-called presystolic period, lasting 0.1 seconds, atrial systole begins. Vibrations of the walls of the heart, caused by atrial systole and additional flow into the ventricles of blood expelled from the atria, lead to the appearance fourth heart sound. Normally, a low-amplitude and low-frequency 4th tone is never heard, but can be determined on FCG in individuals with bradycardia. In pathology, it becomes high, high-amplitude, and with tachycardia forms a gallop rhythm.
With normal listening to the heart, only 1 and 2 heart sounds are clearly audible. 3 and 4 tones are normally not audible. This is due to the fact that in a healthy heart, the blood entering the ventricles at the beginning of diastole does not cause sufficiently loud sound phenomena, and tone 4 is actually the initial component of tone 1 and is perceived inseparably from tone 1. The appearance of 3 tones can be associated both with pathological changes in the heart muscle, and without pathology of the heart itself. Physiological 3 tone is heard more often in children and adolescents. In people over 30 years of age, the 3rd tone is usually not heard due to a decrease in the elasticity of their heart. It appears in those cases when the tone of the heart muscle decreases, for example, with myocarditis, and the blood entering the ventricles causes vibration of the ventricular myocardium that has lost tone and elasticity. However, in cases where the heart muscle is not affected by inflammation, but simply its tone decreases, for example, in a physically very trained person - a skier or a football player of a high sports category, who is in a state of complete physical rest, as well as in young people, in patients with impaired autonomic tone, blood entering the relaxed ventricles of the heart can cause physiological 3 tones. The physiological 3rd tone is best heard directly with the ear, without the use of a phonendoscope.
The appearance of the 4th heart sound is unambiguously associated with pathological changes in the myocardium - with myocarditis, conduction disturbance in the myocardium.
Places for listening to heart sounds. Despite the fact that heart sounds occur in a limited space, due to their strength they are heard over the entire surface of the heart and even beyond. However, on the chest wall for each of the tones, there are places where they are heard better, and the sounds that occur in other places of the heart area interfere the least.
It could be assumed that the places of the best listening to heart sounds correspond to the points of their occurrence. However, this assumption is only valid for pulmonary artery tone. In reality, the points of best listening to the valves of the heart do not coincide with the points of their projection onto the chest wall. In addition to the proximity of the place of origin of sounds, the distribution of sounds along the blood flow, the density of adherence to the chest wall of that part of the heart in which sounds are formed, also plays an important role. Since there are 4 valve openings in the heart, there are also 4 places for listening to heart sounds and noises that occur in the valve apparatus.
The mitral valve is projected onto the area of attachment of the 3rd left costal cartilage to the sternum, but a relatively thick layer of lung tissue, which is characterized by poor sound conductivity, the proximity of the semilunar valves make it unprofitable to listen to the mitral valve, which forms 1 tone, in this place. First heart sound best heard at the apex of the heart. This is due to the fact that in the region of the apex of the heart, we put a phonendoscope on that part of the chest, behind which lies the apex of the heartformed by the left ventricle. The systolic stress of the left ventricle is stronger than that of the right ventricle. The chords of the mitral valve are also attached in the area close to the apex of the heart. Therefore, 1 tone is heard better in the area of \u200b\u200bfitting the apex of the left ventricle to the chest.
With the expansion of the right ventricle and the displacement of the left ventricle posteriorly, 1 tone begins to be heard better over the right ventricle of the heart. The tricuspid valve that generates the first tone is located behind the sternum on the line connecting the place of attachment to the sternum of the 3rd costal cartilage on the left and the 5th cartilage on the right. However, it is heard better somewhat below the projection of the atrioventricular tricuspid valve onto the chest wall, at the lower end of the body of the sternum, since in this place the right ventricle is directly adjacent to the chest wall. If the lower part of the sternum is somewhat depressed in a patient, it is not possible to firmly place the phonendoscope on the chest in this place. In this case, you should move the phonendoscope slightly to the right at the same level until it fits snugly against the chest.
Second heart sound best heard on the basis of the heart. Since the second tone is predominantly valvular, it has 2 points of the best auscultation - at the point of auscultation of the pulmonary valves and at the point of auscultation of the aortic valves.
The sound phenomena of the pulmonary valve, which form the 2nd heart sound, are best heard over that place of the chest wall, which is located closest to the mouth of the pulmonary artery, namely in the second intercostal space to the left of the sternum. Here, the initial part of the pulmonary artery is separated from the chest wall only by a thin edge of the lung.
The aortic valves are laid deeper than them, located slightly medially and below the valves of the pulmonary artery, and even closed by the sternum. The tone generated by the slamming of the aortic valves is transmitted along the blood column and the walls of the aorta. In the 2nd intercostal space, the aorta is closest to the chest wall. To assess the aortic component of tone 2, a phonendoscope should be placed in the second intercostal space to the right of the sternum.
Conducting auscultation of the heart, follow a certain order of listening. There are 2 rules (orders) for auscultation of the heart - the "eight" rule and the "circle" rule.
The "rule of eight" involves listening to the valves of the heart in descending order of the frequency of their defeat in rheumatic lesions. Listen to the heart valves according to the "eight" rule in the following sequence:
1 point - the apex of the heart (the point of listening to the mitral valve and the left atrioventricular orifice),
2nd point - 2nd intercostal space at the right edge of the sternum (auscultation point of the aortic valve and aortic orifice),
3 point - 2 intercostal space at the left edge of the sternum (the point of listening to the valve of the pulmonary artery and its mouth),
4 point - the base of the xiphoid process (the point of listening to the tricuspid valve and the right atrioventricular orifice).
5 point Botkin - Erb - 3rd intercostal space at the left edge of the sternum (additional auscultation point of the aortic valve, corresponding to its projection).
During auscultation, according to the "circle" rule, first listen to the "internal" heart valves (mitral and tricuspid), and then the "external" heart valves (aortic and pulmonary arteries), then listen to the 5th Botkin-Erb point. Listen to the heart valves according to the "circle" rule in the following sequence:
1 point - the top of the heart,
2 point - the base of the xiphoid process,
3 point - 2 intercostal space at the right edge of the sternum,
4 point - 2 intercostal space at the left edge of the sternum,
5 point Botkin - Erb - 3rd intercostal space at the left edge of the sternum.
Listening to heart sounds determine the correctness of the rhythm, the number of fundamental tones, their timbre, the integrity of the sound, the volume ratio of 1 and 2 tones. When additional tones are detected, their auscultatory features are noted: relation to the phases of the cardiac cycle, loudness and timbre. To determine the melody of the heart, one should mentally reproduce it using syllabic phonation.
Difference 1 from 2 heart sounds. 1 tone is longer and slightly lower than 2 tones. At the places of listening to the flap valves, it is usually stronger than 2 tones. The 2nd tone, on the contrary, is somewhat shorter, higher and stronger than the 1st at the places where the semilunar valves are heard. At the base of the heart, heart sounds are best conveyed in syllables. Bu" = tu" n,
and on the stomach Boo" = dumb.
It should be noted that in some perfectly healthy people, the 2nd tone is stronger than the 1st and at the places where the leaflets are auscultated. Sometimes, with rapid and, especially, irregular, arrhythmic activity of the heart, 1 tone can be difficult to distinguish from the 2nd.
Change in the strength of heart sounds.
Heart sounds can change in strength, character, bifurcate, additional tones can occur and peculiar heart rhythms are formed. Changes in heart tones may depend on the following main factors: 1. Changes in the contractile function of the ventricles, 2. Changes in the physical properties of the valves, 3. Changes in the level of blood pressure in the aorta and pulmonary artery, 4. From the non-simultaneity of the occurrence of individual components, 5. From external factors - changes in the properties of the sound-conducting medium - the lungs and chest wall, the state of organs adjacent to the heart.
Decreased heart sounds. The strength of heart tones is weakened, first of all, in healthy people with a thick chest wall, with powerful muscle development and, especially, with excessive development of subcutaneous fatty tissue, in patients with edema, subcutaneous emphysema in the region of the heart. The development of pulmonary emphysema is even more important for weakening the volume of heart sounds, since emphysematous lung tissue is characterized by low sound conductivity. With severe emphysema, heart sounds become barely audible. In patients with hydrothorax, pneumothorax, hydropericardium, there is also a sharp decrease in the volume of heart sounds.
The weakening of the heart sounds can be associated not only with external, in relation to the heart, causes, but also with cardiac pathology. Heart sounds weaken with a decrease in the speed and strength of contractions of the ventricles of the heart due to myocardial weakness. This can be observed in severe infectious diseases that occur with high myocardial intoxication, with myocarditis, in patients with hypertrophy and dilatation of the ventricles of the heart. Since the loudest component of any heart sound is the valvular component, if the closure of one or another heart valve is disturbed, the tone that forms during the operation of the valve weakens sharply, up to complete disappearance. In patients with insufficiency of the mitral or tricuspid valves, 1 tone sharply weakens. In patients with insufficiency of the valves of the aorta or pulmonary artery, a weakening of the 2nd tone is noted. The weakening of the 2nd heart sound is noted in patients with a drop in blood pressure in the large or in the pulmonary circulation, when the semilunar valves slam shut less than usual.
Amplification of all heart sounds observed with: 1) a thin chest wall, 2) when the heart is adjacent to the chest wall with a larger area than usual, for example, with wrinkling of the lungs, 3) with anemia, when, due to a decrease in blood viscosity, heart sounds become clapping, sharp, 4) in those cases when the speed and strength of myocardial contraction increases, for example, during physical exertion, in patients with thyrotoxicosis, with neuropsychic arousal. With insufficient filling of the ventricles with blood, for example, with narrowing (stenosis) of the mitral orifice, orifice of the tricuspid valve, with an extraordinary contraction of the heart (with extrasystole), contractions of the ventricles of the heart that are poorly filled with blood occur faster than usual. Therefore, in such patients, a sharp increase in tone 1 is also noted.
Gain 2 tones, or as they say more often, accent 2 tones over the aorta and pulmonary artery, is common and has significant diagnostic value. In children and people under the age of 20 years, the 2nd tone over the pulmonary artery is normally louder than over the aorta. In older people, the 2nd tone over the aorta becomes louder than over the pulmonary artery. Strengthening of the 2nd tone above the aorta, its accent, is noted with an increase in blood pressure. With the sealing of the aortic valve cusps and, especially, with sclerosis of the aorta itself, the 2nd tone reaches considerable strength and acquires a metallic hue. Similarly, there will be an accent of 2 tones on the pulmonary artery in patients with pulmonary hypertension of any origin - with heart defects, with acute or chronic pulmonary pathology, ranging from lobar pneumonia to emphysema.
splitting of tones. Bifurcation of tones is such a phenomenon when one of the two heart tones is decomposed into 2 parts, freely caught by our ear as separate sounds. If this gap is very small and is not perceived by ear as separate sounds, then one speaks of tone splitting. All transitions are possible between the bifurcation of the tone and its splitting, therefore there is no clear distinction between them.
Bifurcation 2 tones. Non-simultaneous closing of semilunar valves is the result of different duration of systole of the left and right ventricles. Systole ends the sooner the less blood the ventricle has to transfer to the aorta or pulmonary artery, the easier it is to fill them and the lower the blood pressure in them.
Above the base of the heart, a bifurcation of 2 tones can occur in a healthy person at the end of inhalation and at the beginning of exhalation as a physiological phenomenon. As a pathological phenomenon, bifurcation is often observed in mitral valve defects, and especially often in mitral stenosis. This bifurcation of 2 tones is best heard in the 3rd intercostal space on the left side of the sternum. With mitral valve stenosis, the left ventricle is poorly filled with blood in the diastolic phase and less than usual amount of blood is ejected into the aorta. Consequently, the systole of the left ventricle of the heart decreases in time against the usual value. At the same time, these patients have high pulmonary hypertension, which means that the systole of the right ventricle takes longer than usual. As a result of these changes in hemodynamics, non-simultaneous slamming of the valves of the aorta and the pulmonary trunk occurs, heard as a bifurcation of 2 tones. Thus, bifurcation of 2 tones on the aorta and on the pulmonary artery cause the following conditions: 1) pressure rise in one of the vessels and normal pressure in the other, 2) low pressure in one of the vessels and normal in the other, 3) high pressure in one vessel and low in the other, 4) increased blood supply in one of the ventricles, 5) reduced blood supply to one of the ventricles, 6) increased filling of one of the ventricles and reduced filling of the other ventricle of the heart.
Bifurcation of 1 tone. It is heard when a normal tone is always followed by a weak abnormal tone. This phenomenon can occur in 10% of healthy people with auscultation in the supine position. As a pathological phenomenon, bifurcation of the 1st tone occurs with aortic sclerosis and with increased blood pressure in the systemic circulation.
Mitral valve opening tone. In patients with mitral stenosis, with the correct rhythm of heart contractions (without atrial fibrillation), an increase in the number of heart tones is observed, resembling a bifurcation of 2 tones, since the third additional tone quickly follows after the 2nd normal heart sound. This phenomenon is best heard over the apex of the heart. In healthy people, in the phase of rapid filling of the ventricles of the heart with blood, the leaflets of the mitral valve are silently pushed aside by blood. In patients with mitral valve stenosis, at the beginning of the diastole phase, when the rapid filling of the ventricles with blood begins, the shortened and sclerotic leaflets of the mitral valve form a funnel-shaped diaphragm. They cannot open freely and move away to the walls of the ventricle, sharply tighten under the pressure of blood and generate a mitral valve opening tone. In this case, a kind of three-membered heart rhythm is formed, called quail rhythm. The first component of this three-term rhythm is the first tone. It is followed by a second tone at the usual time interval. Almost immediately after the second tone, the sound of the opening of the mtral valve follows at a short interval. There is a rhythm that can be transmitted by sounds Ta-tara, reminiscent, in the figurative expression of the old clinicians, the cry of a quail "sleep - in-ra." A quail rhythm is heard with normo- or bradycardia. Only in the absence of tachycardia by ear can one distinguish the difference in the intervals between the first - second and second - third components of the resulting three-term rhythm.
gallop rhythm. The bifurcation of the first tone is sometimes very sharp. The part split off from the main tone is separated from it by a certain interval, clearly perceived by ear, and is heard as a separate independent tone. Such a phenomenon is no longer called a bifurcation of tone, but a gallop rhythm, reminiscent of the clatter of the hooves of a galloping horse. This peculiar three-term rhythm appears against the background of tachycardia. The intervals between the first - second and second - third tones are perceived by the ear as the same, the interval between the third and the first sound following it of the next triad is perceived as somewhat larger. The emerging rhythm can be transmitted by sounds like ta-ra-ra, ta-ra-ra, ta-ra-ra. The gallop rhythm is best defined above the apex of the heart and in 3-4 intercostal spaces to the left of the sternum. It is heard better directly with the ear than with the help of a phonendoscope. The gallop rhythm intensifies after a slight physical effort, when the patient moves from a vertical to a horizontal position, as well as at the end of inhalation - at the beginning of exhalation in a slowly and deeply breathing person.
An additional third tone with a gallop rhythm usually sounds muffled and short. It can be located in relation to the main tones as follows.
An additional tone can be heard during a long pause closer to the first tone. It is formed by the separation of the atrial and ventricular components of the first tone. It is called the presystolic gallop rhythm.
An additional tone can be heard in the middle of a great pause of the heart, i.e. in the middle of diastole. It is associated with the appearance of 3 heart sounds and is called the diastolic gallop rhythm. Phonocardiography made it possible to distinguish protodiastolic (at the beginning of diastole) and mesodiastolic (in the middle of diastole) gallop rhythms. The proto-diastolic gallop rhythm is due to severe damage to the ventricular myocardium, most often insufficiency of the previously hypertrophied left ventricle. The appearance of an additional tone in diastole is caused by the rapid straightening of the flabby muscle of the left ventricle when it is filled with blood. This variant of the gallop rhythm can occur with normo- and even with bradycardia.
An additional tone can be heard immediately after the first tone. It is caused by simultaneous excitation and contraction of the left and right ventricles of the heart in case of conduction disturbances along the legs of the His bundle or along their branches. It is called the systolic gallop rhythm.
If, with high tachycardia, there are 3 and 4 heart sounds, then a short interval between them can lead to the fact that the four-membered heart rhythm recorded on the phonocardiogram is perceived by ear as a three-membered rhythm and a summed mesodiastolic gallop rhythm occurs (summation of 3 and 4 tones).
pendulum rhythm- This is a two-term rhythm with equal pauses between 1 and 2 heart sounds. It occurs due to the lengthening of the systole of the ventricles during their hypertrophy, with cardiosclerosis and myocarditis.
Embryocardia called pendulum rhythm, auscultated with tachycardia. Normally, this rhythm is heard in the fetus. When an adult develops, embryocardia is evidence of severe myocardial damage, primarily an inflammatory process.
Heart sounds are the sum of various sound phenomena that occur during the cardiac cycle. Usually two tones are heard, but in 20% of healthy individuals the 3rd and 4th tones are heard. With pathology, the characteristic of tones changes.
The 1st tone (systolic) is heard at the beginning of systole.
There are 5 mechanisms for the occurrence of the 1st tone:
- The valvular component arises from the sound phenomenon that occurs when the mitral valve closes at the beginning of systole.
- Oscillation and closure of the tricuspid valve leaflets.
- Fluctuations of the walls of the ventricles in the phase of isometric contraction at the beginning of systole, when the heart pushes blood into the vessels. This is the muscle component of the 1st tone.
- Fluctuations in the walls of the aorta and pulmonary artery at the beginning of the period of exile (vascular component).
- Vibrations of the walls of the atria at the end of atrial systole (atrial component).
The first tone is normally auscultated at all auscultatory points. The place of its evaluation is the top and the Botkin point. Assessment method - comparison with the 2nd tone.
The 1st tone is characterized by the fact that
a) occurs after a long pause, before a short one;
b) at the top of the heart it is more than the 2nd tone, longer and lower than the 2nd tone;
c) coincides with the apex beat.
After a short pause, a less sonorous 2nd tone begins to be heard. The 2nd tone is formed as a result of the closure of two valves (aorta and pulmonary artery) at the end of systole.
There is a mechanical systole and an electrical systole that does not coincide with the mechanical one. The 3rd tone can be in 20% of healthy people, but more often in sick people.
The physiological 3rd tone is formed as a result of fluctuations in the walls of the ventricles during their rapid filling with blood at the beginning of diastole. It is usually noted in children and adolescents due to the hyperkinetic type of blood flow. The 3rd tone is recorded at the beginning of diastole, not earlier than 0.12 seconds after the 2nd tone.
Pathological 3rd tone forms a three-membered rhythm. It occurs as a result of the rapid relaxation of the muscles of the ventricles that have lost their tone with the rapid flow of blood into them. This is the "cry of the heart for help" or gallop rhythm.
The 4th tone can be physiological, occurring before the 1st tone in the diastolic phase (presystolic tone). These are the fluctuations of the walls of the atria at the end of diastole.
Normally occurs only in children. In adults, it is always pathological, due to contraction of the hypertrophied left atrium with a loss of ventricular muscle tone. This is the presystolic gallop rhythm.
Clicks can also be heard during auscultation. A click is a high-pitched, low-intensity sound heard during systole. Clicks are distinguished by high tonality, shorter duration and mobility (inconstancy). It is better to listen to them with a phonendoscope with a membrane.
