Basic rules for conduction of auscultation of the heart
Mar 21, 2018
One of the oldest methods of diagnosing cardiac pathology is auscultation of the heart. Despite this, it still has not lost its relevance and allows an experienced specialist to deliver or clarify the diagnosis.
When performing a study such as auscultation of the heart, the points at which the valve works do not always correspond to their anatomical projection on the surface of the chest. There are rules that determine the sequence, which is determined by the frequency of damage to the valve apparatus:
- The second intercostal space to the right of the sternum.
- Parallel point to the left of the sternum.
- The lower third of the sternum.
- The site of attachment of 3 ribs at the left edge of the sternum( Botkin-Erbe point).
Heart auscultation is normal
Auscultation of the heart normally allows you to listen, most often, two tones, but sometimes the third and even the fourth can be determined.
The first tone occurs during contraction of the heart - systole. Therefore, it is called systolic. The first tone consists of several sound generators( components) - the muscular, which appears as a result of contraction of the ventricles, and the valve( when the valves of the two- and tricuspid valves slam shut).It also includes the atrial and vascular component( as a result of oscillation of the walls of the aorta and pulmonary artery).
The second tone is heard due to closure of the valves of the aortic and pulmonary valves. It coincides in time with the onset of relaxation of the heart muscle - the diastole, and is called diastolic.
Tones are best heard from thin patients, as the layer of adipose tissue has the ability to muffle sounds.
A third tone can be heard when the blood flow to the ventricles is sharply increased during diastole. It is best heard in the region of the apex of the heart, and in the supine position. It is difficult for an inexperienced person to catch this sound, because it is quiet enough.
The fourth tone occurs when the ventricles are filled with blood from the atria after the end of the diastole. The last two tones are well audited in young children and people with asthenic physique.
At auscultation, you can sometimes listen to noises. They are of organic origin and functional. Organic noise indicates the presence of cardiopathology, and can occur when blood passes through the constriction of the hole, as a result of the presence of stenoses and with regurgitation of blood during the development of defects in the valve apparatus.
Functional noises are most often in childhood and adolescence, unlike organic, they can take place under physical stress, they are listened to differently depending on the position of the body, variable in strength and duration. They do not require treatment and disappear with age.
Auscultatory pattern in hypertension
Auscultation of the heart in hypertensive disease has its own characteristics. As a result of constant high pressure, the load experienced by the left ventricle results in its increase. As hypertrophy increases, weaken the first tone when listening at the top. This means not a deterioration of myocardial contractility, but a degree of severity of sclerosis.
With increasing heart failure, with hypertension II-III degree begins to listen to the fourth tone. It is best heard on the basis of the xiphoid process and in the projection of the apex. It is better to listen to it when the patient is lying on his left side. This indicates the preservation of the active hemodynamic process with a decrease in the diastolic elongation of the enlarged wall of the left ventricle.
Approximately one in three patients may have a third tone. He is also best heard if a person lies on his left side. When the pressure decreases, it weakens or may completely disappear. Usually the appearance of a third tone indicates the development of insufficiency, but during an exacerbation of the pathological process, one can speak of a temporary increase in diastolic pressure in the left ventricle.
In most patients with essential hypertension, various noises can be detected with auscultation. Most often they are heard during systole on the right side in the second intercostal space and on the apex. Their appearance is associated with a relative narrowing of the aortic orifice, and sometimes with the formation of an asymmetric enlargement of the interventricular septum. If the noise is heard to the left of the sternum and from behind between the shoulder blades, this indirectly indicates coarctation of the aorta.
The marked dilatation of the left ventricular cavity can cause a relative insufficiency of the mitral valve, and also manifests itself in the form of systolic murmur. This usually happens after a heart attack or with severe heart failure with cardiosclerosis.
The second tone with pronounced hypertension has an emphasis on the aorta. It can be heard on the right side in the second intercostal space, which is explained by the displacement of the aorta in comparison with the physiological norm. Strengthening of the second tone, as well as tympanic( musicality) of its sound, speaks about the duration of the course of hypertension and the degree of its severity, because it happens because of sclerosing the walls of the aorta.
Rules for auscultation of the heart
Propaedeutics of internal diseases teaches proper auscultation of the heart. To correctly interpret the sound picture and obtain the most objective information, you must follow certain rules:
- For better perception of sounds that can be determined by listening to the heart, there should be silence in the room, sometimes the doctor may ask the patient to hold his breath. Auscultation of cardiac tones is performed in a standing position, lying on the back and on the left side.
- In the room where auscultation is performed, there should be a comfortable air temperature.
- Auscultation is performed with a phonendoscope, the doctor should be located during the diagnosis to the right of the patient.
- In the presence of hair, it is moistened with a special gel, or shaved at the listening position.
- Before the study, the patient should not use tea, coffee or other beverages that can increase the number of heartbeats, and thereby change the results of auscultation.
- Sometimes the patient, at the direction of the doctor, must perform a small physical load. It can be squats or walking on the stairs.
- Evaluation of the work of the heart should begin with the evaluation of tones - their audibility, rhythm, sound characteristics. And then go on to the characteristic of noise.