If you’ve ever listened to a healthy heart through a stethoscope, the sound you hear is a familiar, two-beat rhythm: lub-dub, lub-dub, lub-dub . This is not just a random noise; it is the acoustic signature of your heart valves snapping shut. It is the sound of life itself.
The order is based on the in the heart cycle. Systole (contraction) always comes before diastole (relaxation). The AV valves (lub) must close at the start of contraction. The semilunar valves (dub) close at the end of contraction. what is lub dub sound
A murmur is a valve closing. It is the sound of turbulent blood flow . If you’ve ever listened to a healthy heart
In short: (AV valves close). Dub (Semilunar valves close). Pause (Heart refills). Repeat 60–100 times per minute. That is the rhythm of life. The order is based on the in the heart cycle
LUB (ventricles squeeze, AV valves close) → DUB (ventricles relax, semilunar valves close) → pause (heart fills with blood) → LUB ... Part 4: Lub-Dub vs. Dub-Lub (A Common Confusion) People often ask: Why is it "lub-dub" and not "dub-lub"?