The S1 sound is often described as a "lub" and is the first of the two main heart sounds that can be heard with a stethoscope during auscultation.
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? s1 heart sounds
