First Heart Sound plus Aortic Ejection Click

A single first heart sound (S1) followed by an aortic ejection click (AEC) can also mimic a split first heart sound. An AEC follows S1 by 50 milliseconds. An aortic ejection click is caused by thickened aortic valve leaflets. This is commonly seen in a bicuspid aortic valve, a congenital abnormality where someone is born with two aortic valve leaflets instead of the normal three. Listen carefully to the second sound of the pair. If it is an AEC it will have a shorter duration and a higher pitch than the first sound of the pair (S1). The AEC is best heard at the Aortic valve area where splitting of S1 is not heard.

Auscultation Sounds

Patient Recording

First Heart Sound plus Aortic Ejection Click

Patient Recording - Half Speed Playback

Position

The patient's position should be sitting.

Listening Tips

Systole:high-pitched sound, early in systole, short duration

Waveform (Phonocardiogram)

Observe

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An aortic ejection click is caused by thickened aortic valve leaflets. This is commonly seen in a bicuspid aortic valve, a congenital abnormality where someone is born with two aortic valve leaflets instead of the normal three.

Authors

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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