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Second Heart Sound and Late Systolic Click

Second Heart Sound and Late Systolic Click

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

Auscultation Sounds

auscultation sound from lesson

Patient Recording

patient heart or lung sound
Second Heart Sound and Late Systolic Click

Patient Recording - Half Speed Playback

patient heart or lung sound
Second Heart Sound and Late Systolic Click


Patient position
The patient's position should be supine.

Listening Tips

Systole:higher-pitched click late in systole with short duration

Waveform (Phonocardiogram)


//embedding heart animation


These authors contributed the audio recordings and text found in this reference guide: Jon Keroes, MD,Diane Wrigley, PA, and David Lieberman.
Medically reviewed by Dr. Barbara Erickson, PhD, RN, CCRN.



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