Sign in or Join to use this module.

Third Heart Sound - Physiologic Reference Guide

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 25Hz and 50Hz). 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.

Auscultation Sound From Lesson

auscultation sound from lesson

Patient Recording

patient heart or lung sound
Third Heart Sound - Physiologic

Patient Recording - Half Speed Playback

patient heart or lung sound
Third Heart Sound - Physiologic


Patient position
The patient's position should be supine.

Listening Tips

Diastole:S3 in early diastole. Low-pitch. Galloping (S1,S2,S3) or intermittent sound

Waveform (Phonocardiogram)

Observe Cardiac Animation

Authors and Sources

Authors and Reviewers


Return to Reference Guide Index Page

Third Heart Sound - Physiologic | Description, Audio and Animations | #35
An error has occurred. This application may no longer respond until reloaded. Reload 🗙