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.
A normal heartbeat consists of two primary sounds, medically termed S1 and S2. The Texas Heart Institute Heart Murmurs - The Texas Heart Institute lub dub dub heart sound
The "lub dub" sound is the rhythmic signature of a healthy heart, but an extra beat—creating a "lub dub dub" pattern—often signals something more complex. This three-beat rhythm, known medically as a , can be a normal occurrence in specific groups or a critical warning sign of heart failure. The Anatomy of "Lub Dub" (S1 and S2) In some cases, a third heart sound, often
This third sound occurs shortly after S2 during the early phase of diastole (when the heart is resting and filling with blood). It is caused by a large volume of blood rushing rapidly into the ventricles, making the ventricular walls vibrate. When is it Normal? This three-beat rhythm, known medically as a ,