Third Heart Sound - Physiologic

The third heart sound is heard early in diastole. Along with the first and second heart sounds, this extra sound creates a gallop cadence and sounds like "Kentucky."

In this auscultation example the second heart sound is unsplit to make it easier for you to distinguish the third heart sound.

The third heart sound is very low frequency (between 25 hz and 50 hz). Listen with the bell of the stethoscope at the cardiac apex. Asking the patient to lie on his left side will frequently increase the intensity of the third heart sound.

A third heart sound is heard on occasion in normal individuals with no cardiac pathology.

Third Heart Sound - Physiologic
The recommended auscultation position for the stethoscope is the Mitral position. For this sound, use stethoscope's bell.


maneuver
The recommended patient position is Supine

Phonocardiogram

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

Heart Animation

Lessons
left button        right button



Listening Tips
A synopsis of important sound features and timing for this abnormality.
S2: Unsplit.
Diastole: S3 in early diastole. Low pitch. Galloping (S1,S2,S3) or intermittent sound.
CaseID35
CourseID22
CourseCaseOrder4
ID18