Heart and Lung Sounds Reference Guide

Third Heart Sound - Physiologic Auscultation Reference

Patient Normal Speed

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Patient Half Speed

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Simulated Full Speed

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Lesson

For heart sounds listen to the synthetic sound while reviewing this lesson.

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.

The waveform(s) seen above are a chart of sound amplitude (loudness) on the vertical axis against time on the horizontal axis.

Listening Tips

A summary of the key aspects of this heart or lung sound.
S2: Unsplit.
Diastole: S3 in early diastole. Low pitch. Galloping (S1,S2,S3) or intermittent sound.

Auscultation Method

The recommended patient position is supine

For this sound, use stethoscope's bell The recommended auscultation position for the stethoscope is mitral

Relevant Courses

If you wish to review a complete mobile concerning Third Heart Sound - Physiologic Auscultation Reference and related heart sounds, the modules(s) listed below may be useful. Each lesson includes text that explains the auscultatory sound and its clinical significance. The lesson also includes an audio track for playback. A waveform provides a great way to visualize the sounds. Finally, we also include an animation video. For heart sounds, the video illustrates heart muscle and valve movements along with blood flow. For lung sounds, the primary source of the sounds can be seen. Each module also includes a quiz.

Normal Heart Sounds

Third Heart Sound - Physiologic Auscultation Reference