Page 103 - Clinical Pearls in Cardiology

Auscultation of the Precordium 91

Fig. 7: Genesis of S4

10. How will you differentiate a right ventricular S3 or S4
from a left ventricular S3 or S4?
Both S3 and S4 are low-pitched sounds. They are heard
well with the bell of the stethoscope with the patient in
the left lateral decubitus position. Any maneuver that
increases the venous return to the heart (like assuming
supine posture, elevation of legs, etc.) will help to
accentuate the intensity of these sounds by increasing
the intracardiac blood movements (Table 3 and Fig. 6).
Table 3: Difference between left and right ventricular S3/S4
Left ventricular S3/S4 Right ventricular S3/S4
Maximum intensity at the Maximum intensity at the left
apical area lower sternal border
Expiratory augmentation Inspiratory augmentation
Other signs of left ventricular Other signs of right ventricular
disease disease

11. What is a murmur?
A murmur is a series of audible vibrations due to the
disturbance of the normal laminar blood flow within the