Second Heart Sounds

Second Heart Sound and Late Systolic Click Sounds

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.

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The recommended auscultation position for the stethoscope is the Mitral position. For this sound, use stethoscope's Diaphragm.

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The recommended patient position is Supine

Phonocardiogram

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

Heart Animation

Lessons

1	Second Heart Sound - Physiologically Split #2
2	Second Heart Sound with Persistent Splitting
3	Second Heart Sound with Fixed Splitting
4	Second Heart Sound: Fixed Splitting, Increased Aortic Intensity
5	Second Heart Sound: Fixed Splitting, Decreased Aortic Intensity
6	Second Heart Sound and Late Systolic Click
7	Second Heart Sound and a Tumor Plop
8	Opening Snap and Second Heart Sound

Practice Drill

Listening Tips
A synopsis of important sound features and timing for this abnormality.
Systole: Higher pitched click late in systole with short duration.

CaseID	49
CourseID	24
CourseCaseOrder	6
ID	37