Dub Heart Sound: Lub Dub

The normal heart sound is typically described as "lub-dub." The "lub" sound is caused by the closure of the atrioventricular (AV) valves, specifically the mitral and tricuspid valves, at the beginning of systole (contraction of the heart muscle). This sound is also known as S1.

The "dub" sound is caused by the closure of the semilunar valves, specifically the aortic and pulmonary valves, at the end of systole. This sound is also known as S2.

Lub. Dub. Dub. Listen close — it’s never just two. lub dub dub heart sound

In some cases, a third heart sound, often described as a "dub" sound, can be heard, making the sequence "lub-dub-dub." This third sound, also known as S3, is usually heard in younger individuals and athletes, but can also be a sign of certain heart conditions.

In many cases, an S3 sound is perfectly healthy and is referred to as a . It is commonly heard in: The normal heart sound is typically described as "lub-dub

A normal heartbeat consists of two primary sounds, medically termed S1 and S2. The Texas Heart Institute Heart Murmurs - The Texas Heart Institute

Lub — the start, the spark. Dub — the echo in the dark. Dub — the unexpected mark. This sound is also known as S2

The "lub dub dub" heart sound is an important indicator of a healthy heart, and any changes or abnormalities in the sounds can be a sign of an underlying medical condition. A healthcare professional can use a stethoscope to listen to the heart sounds and diagnose any potential issues.

The second normal sound. It happens when the aortic and pulmonary valves close after the heart has finished pumping blood out to the body and lungs.