First Heart Sounds

First Heart Sound (Minimally Split)

On occasion the first heart sound can be made up of two separate sounds separated by a very small interval (20-30 milliseconds).

The Mitral component (caused by closure of the Mitral valve) comes first and is louder than the Tricuspid component (caused by closure of the Tricuspid valve).

A minimally split first heart sound is a normal variation of the first heart sound.

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Position: Tricuspid
Chestpiece: Diaphragm

Maneuver: Supine

Phonocardiogram

Cardiac Animation

Table of Contents

1	First Heart Sound - Loud
2	First Heart Sound (Minimally Split)
3	First Heart Sound (Markedly Split)
4	First Heart Sound - Decreased Intensity
5	Fourth Heart Sound Plus First Heart Sound
6	First Heart Sound plus Aortic Ejection Click

Practice Drill