This two-part sound is a result of the heart's pumping action, and it's a sign that the heart is working properly. In medical terms, it's referred to as the "S1" and "S2" heart sounds, with "S1" being the "lub" sound and "S2" being the "dub" sound.
The first heart sound, the "lub," is technically known as . It is typically a lower-pitched, slightly longer sound that marks the beginning of systole , the phase when the heart's lower chambers (ventricles) contract. How the Heart Works - How the Heart Beats | NHLBI, NIH heart lub dub sound
Here’s a breakdown of the content behind that sound: This two-part sound is a result of the
The "lub-dub" sound is the normal sound of a healthy heartbeat, caused by the . It is typically a lower-pitched, slightly longer sound
One day, while beating away, Heartie noticed that she made a strange sound. It went like this: "Lub... dub... lub... dub..." She wasn't sure what it meant, but she liked the way it sounded.
Medical professionals refer to these as (the "lub") and S2 (the "dub"). Together, they represent the constant cycle of blood being received, pressurized, and ejected to the rest of the body. 1. The "Lub" (S1): Closing the Inlets