First Heart Sounds

First Heart Sound (Minimally Split) Sounds

Unlock lessons, quizzes and more.

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.

play
pause

The recommended auscultation position for the stethoscope is the Tricuspid position. For this sound, use stethoscope's Diaphragm.

maneuver

The recommended patient position is Supine

Phonocardiogram

This waveform plots sound amplitude on the vertical axis against time on the horizontal axis.

Heart Animation

Lessons

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

Listening Tips
A synopsis of important sound features and timing for this abnormality.
S1: Minimal splitting.

CaseID	39
CourseID	22
CourseCaseOrder	2
ID	27