What Is Lub Dub Sound In Heart -

That silence was the heart’s rest—the brief moment when the chambers refilled with blood, waiting for the next order to beat.

Just like S1, the "Dub" is a composite of two sounds: A2 (Aortic closure) and P2 (Pulmonary closure). "Physiological splitting" is common here. During inhalation, pressure in the chest drops, drawing more blood into the right side of the heart. This delays the closure of the pulmonary valve slightly. Thus, you hear the Aortic valve close ("Dub"), followed a split second later by the Pulmonary valve (a second "b"). During exhalation, they merge back into a single sound. what is lub dub sound in heart

Every second of every day, these gates swung open and snapped shut in perfect sequence. Their job was to keep the river of blood flowing forward. When they worked well, no one in the body noticed them. But they always spoke. They spoke in two syllables. That silence was the heart’s rest—the brief moment