What Is The S2 Heart Sound ✭

The , phonetically known as the " dub " in the "lub-dub" cardiac cycle, is a critical auditory marker signifying the end of ventricular systole and the onset of ventricular diastole. It is produced by the closure of the two semilunar valves—the aortic valve (A2) and the pulmonic valve (P2) .

The most famous S2 of all—the one taught in every medical school—is the heard during a heart attack affecting the left bundle branch. It defies nature: the “dub” splits as you breathe out , not in. A clue hidden in a heartbeat. what is the s2 heart sound

$S_2$ 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). The , phonetically known as the " dub

The S2 sound is actually a composite of two distinct events: Cardiac Second Heart Sounds - Stanford Medicine It defies nature: the “dub” splits as you

But S2 tells stories of illness, too.

The loudness (intensity) of $S_2$ components reflects the pressure behind the valve.