Lub Dub Heart Sounds |link| -

The "lub-dub" of the heart is a result of the valvular apparatus managing the unidirectional flow of blood. S1 marks the beginning of mechanical systole and the closure of the AV valves (mitral and tricuspid). S2 marks the beginning of diastole and the closure of the semilunar valves (aortic and pulmonic). By analyzing the nuances of these sounds, clinicians can non-invasively diagnose a wide array of structural and functional heart diseases.

The characteristic "lub-dub" rhythm represents the fundamental cycle of a beating heart, with each sound marking a critical mechanical event. Often described as , these sounds are the primary focus of cardiac auscultation—the process of listening to the heart through a stethoscope. The "Lub" (First Heart Sound - S1) lub dub heart sounds

Variations in the intensity, timing, or splitting of S1 and S2 can indicate specific diseases. The "lub-dub" of the heart is a result