One of the simplest ways to assess the condition of the heart is to listen to it with a stethoscope.[9] Normally, only two sounds are heard in a healthy heart and they are called S1 and S2. The first sound, S1, is caused by the closing of the atrioventricular valves during the contraction of the ventricles and is usually described as a “pulp” sound. The second sound, S2, is the sound of the semilunar valves closing during ventricular diastole and is often described as a “bear”.[9] Each voice consists of two tones, reflecting the slight difference in the closing time of the two valves.[46] S2 may split into two distinct sounds, either as a result of inhalation or due to various cardiac or valvular problems.[46] Additional heart sounds can appear and give the clicker rhythms. The third heart sound, S3, usually indicates an increase in ventricular blood volume. As for the fourth heart sound, S4, it refers to the atrial murmur produced by the impingement of blood in the stiff ventricle. The presence of the third and fourth heart sounds gives a quadruple trot.[9]
A heart murmur is an abnormal heart sound that may or may not be pathological or benign.[47] One example of a heart murmur is Steele’s murmur, which appears as a musical sound in children, has no symptoms, and disappears in adolescence.[48]
Another type of sound that can be heard is the pericardial rubbing sound, which is heard in cases of pericarditis, where the inflamed membranes can rub against each other and the sound appears.[49]
