Heart sounds

As heart sounds is called the arising during the cardiac action audible oscillations ( 15-400 Hz), which are transmitted to the chest wall. With hook ear or the stethoscope are two of the four heart sounds perceptible ( auscultation, eg at the Erb's point).

• The first heart sound is dull and takes 0.14 s It arises from the fact that the ventricular muscle contracted at the end of the atrioventricular valves ( heart valve between the atrium and ventricle ) to the incompressible blood ( " Muskelanspannungston "). He is best heard over the apex. The former definition of the first heart sound as " the end of the atrioventricular valves " could not keep physiologically. In the normal heart, the closing or opening of AV valves itself is not audible.

• The second heart sound is brighter, louder and shorter ( 0.11 s ) than the first heart sound. It is created by the vibration of the column of blood in the vessels immediately after the conclusion of the pocket flaps of aorta and pulmonary trunk ( " Klappenschlusston "). He is best heard over the base of the heart.

In order to distinguish absolutely arrhythmic patients the first from the second heart sound, you can feel at the same time the pulse auscultation ( the wrist pulse at the radial artery, for example). The heart sound that can be heard simultaneously with the feeling the pulse, the first heart sound.

Physiological (normal ) heart sounds

In phonocardiogram four heart sounds can be differentiated:

• I. Heartbeat in the concentric phase of the heart ( R wave in the ECG)
• Second heart sound when closing the pocket flaps of the two arteries of the heart (shortly after the T wave in the ECG )
• III. Heartbeat in the early filling phase by the inflowing blood into the ventricle ( falls into the anterior third of TP line in the EKG)
• IV heart sound, which is only occasionally found as a sound of atrial contraction (shortly after the P wave on the ECG ).

The 3rd and 4th heart sound are physiologically only in children and adolescents, to a certain degree, in the elderly they are always to be regarded as pathological. The third heart sound comes about by the impact of the blood beam to the rigid wall of the ( insufficient ) ventricle; the presence of a third heart sound is of prognostic importance in heart failure and in acute myocardial infarction. The fourth heart sound is caused by the increased atrial contraction for ventricular filling more difficult. Are 3rd and 4th heart sound simultaneously present, with rapid heartbeat ( tachycardia), a " summation gallop " arise.

The mitral ( MOET ) s will be heard after the second heart sound in patients with narrowing of the mitral valve ( mitral stenosis ) possibly in early diastole 0.08-0.1. He usually closes the typical " low-frequency diastolic rumble " to.

Pathological ( abnormal ) heart sounds

Added to the heart sounds and murmurs, then these as opposed to the heart sounds usually indicate valvular heart disease. For example, a heart murmur during systole ( the working phase of the heart) usually on a stenosis ( narrowing) of the pocket flaps or insufficiency ( leakage ) due to the atrioventricular valves, a diastolic murmur ( during the resting phase of the heart ), however, mostly for leaking pocket flaps or narrowed atrioventricular valves. To listen to the normal and pathological heart sounds and murmurs a stethoscope is used. It should be noted that the pathological heart sounds, so the third and fourth heart sound, is a low frequency and thus are usually, but not to hear only the so-called funnel with the membrane of the stethoscope.