S1 Heart Sounds ★ Official & Recent

You’ll hear S1 loudest at the apex of the heart (5th intercostal space, mid-clavicular line). 🩺 Clinical Pearls S1 Heart Sound - Learn How to Auscultate (Part 8)

Would you like a similar review of S2, splitting patterns, or murmurs? s1 heart sounds

In a normal cardiac cycle, the sequence of heart sounds is: You’ll hear S1 loudest at the apex of

The first heart sound, , is the familiar "lub" in the heart’s "lub-dub" rhythm. It signals the official start of systole —the phase when your heart contracts to pump blood to the rest of the body. 💓 The Basics: What is S1? It signals the official start of systole —the

| Feature | S1 | S2 | |---------|----|----| | Timing | Start of systole | End of systole | | Best heard | Apex (mitral/tricuspid) | Base (aortic/pulmonic) | | Relation to carotid pulse | with upstroke | Follows pulse | | Effect of inspiration | Splits slightly (RBBB → wide) | Splits physiologically |

It’s produced by the closure of the Atrioventricular (AV) valves —the Mitral and Tricuspid valves. These valves slam shut to prevent blood from flowing back into the atria when the ventricles contract. Sound: Low-pitched and slightly longer in duration than S2.

Abnormalities in S1 heart sounds can indicate underlying cardiac issues, making it an essential component of cardiac assessment.