But S2 tells stories of illness, too.
Caused by the closure of the pulmonic valve. Due to lower pressures on the right side of the heart (approx. 10 mmHg), P2 is softer and is typically only heard at the left upper sternal border. Physiologic Splitting what is the s2 heart sound
If the split is —meaning the valves close in reverse order (P2 before A2) and the split narrows on inspiration instead of widening—that could murmur of left bundle branch block or aortic stenosis . The left ventricle struggles to finish its squeeze, so A2 arrives late. But S2 tells stories of illness, too
$S_2$ occurs at the termination of ventricular ejection. As the ventricles begin to relax (isovolumic relaxation), the pressure within the ventricles falls below the pressure in the great arteries (aorta and pulmonary artery). 10 mmHg), P2 is softer and is typically
Auscultation of the heart remains a cornerstone of the physical examination. The second heart sound ($S_2$) is arguably the most informative of the heart sounds due to its sensitivity to changes in pressure gradients and ventricular function. $S_2$ is a high-frequency sound generated by the sudden deceleration of blood and the elastic recoil of the semilunar valves (aortic and pulmonic). Unlike the first heart sound ($S_1$), which is influenced by ventricular contractility, $S_2$ is primarily determined by the pressure dynamics of the systemic and pulmonary circulations.