Heart and Lung Sounds Reference Guide

Second Heart Sound and Late Systolic Click 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.

Certain heart sound configurations mimic a split second heart sound.

One of these conditions is a late systolic click plus a single second heart sound (S2). Since the late systolic click occurs just before the S2 it is easy to confuse the two with a split S2.

Listen carefully to the two sounds. If the first of the pair is of higher frequency and shorter duration than the second, it is a late systolic click followed by a single second heart sound.

Another way of distinguishing a late systolic click from a split S2 is to move the stethoscope head to the pulmonic area. The late systolic click will disappear and you will only hear the single S2.

A late systolic click is caused by degeneration of the mitral valve leaflets. This degeneration causes the closing of the leaflets to make a "clicking" sound during late systole.

On the Anatomy tab you will see prolapse of the anterior lateral mitral valve leaflet which is the cause of the late systolic click.

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.
Systole: Higher pitched click late in systole with short duration.

Auscultation Method

The recommended patient position is supine

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

Relevant Courses

If you wish to review a complete mobile concerning Second Heart Sound and Late Systolic Click 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.

Second Heart Sounds	24
EKG Basics	301

Second Heart Sound and Late Systolic Click Auscultation Reference