What Causes The Lub Dub Sound Of The Heart Jun 2026

The pause between the "lub" and the "dub" is very short, representing the time it takes for the ventricles to empty. The longer pause occurs after the "dub" and before the next "lub," which is the period when the heart is resting and refilling. When the Sound Changes: Murmurs and Extra Sounds

Leads from the right ventricle to the lungs. what causes the lub dub sound of the heart

The vibration of these valves closing, combined with the sudden tension in the surrounding heart strings (chordae tendineae) and the turbulence of the blood hitting the closed valves, creates the "lub" sound. The Second Sound: The "Dub" (S2) The pause between the "lub" and the "dub"

The . Common lifestyle habits that keep heart valves healthy. The vibration of these valves closing, combined with

Blood in the arteries attempts to flow backward into the ventricles due to gravity and pressure gradients. The semilunar valves snap shut to prevent this regurgitation. The sudden cessation of this reverse blood flow and the impact of the blood against the closed valve cusps creates the sharp, high-frequency "dub."

After the upper chambers (atria) pump blood into the lower chambers (ventricles), the atrioventricular (AV) valves —the mitral and tricuspid valves—snap shut.