What Is The S2 Heart Sound //top\\ -

But S2 tells stories of illness, too.

Picture the instant. Ventricles have just finished squeezing. Their pressure plummets. For a fraction of a second, the aorta (high pressure) and the pulmonary artery (lower pressure) still hold blood that wants to surge backward into the heart. But the aortic and pulmonic valves snap shut like umbrellas blown inside out by the wind—only in reverse. Their cusps meet, tense, and vibrate. That vibration, transmitted through the chest wall, is S2. what is the s2 heart sound

S2 is the sound of closure. Not of all doors, but of the two great exit valves from the heart’s lower chambers: the aortic valve on the left, and the pulmonic valve on the right. But S2 tells stories of illness, too

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. Their pressure plummets