The S2 sound is not actually a single event but is composed of two distinct components:
If the split becomes —present on both inhale and exhale, never coming back together—that might whisper of an atrial septal defect , a hole between the heart’s upper chambers. Extra blood sloshes through the right side, always delaying P2. what is the s2 heart sound
When you breathe in, your diaphragm descends. The pressure inside your chest drops, drawing more blood into the right heart. That extra blood takes a little longer to eject through the pulmonic valve, so P2 is delayed. Meanwhile, the left heart receives slightly less blood during inspiration, so A2 happens a hair earlier. The result: on a good exhalation, “dub” sounds like one crisp note. On a deep breath in, the “dub” splits into two soft, fleeting clicks— tuh-dup . This is called of S2. It is normal, even beautiful, a sign of a flexible, responsive heart. The S2 sound is not actually a single
And then there is the of systemic hypertension , slamming shut like a heavy door in a storm. Or the soft A2 of aortic stenosis , where calcified valves cannot snap, only sigh shut. The pressure inside your chest drops, drawing more
In approximately 90% of healthy individuals, S2 is "split" during inhalation. This is known as : S2 Heart Sound Topic Review - Healio
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.