Opening Snap and Second Heart Sound

An opening snap occurring early in diastole along with a single second heart sound can mimic a split second heart sound. An opening snap is caused by thickened valve leaflets. When they open, it produces a snapping sound. The more severe the thickening the earlier in diastole the opening snap occurs. In this example you are hearing an opening snap, which occurs 75 milliseconds after the start of the second heart sound.

Auscultation Sounds

Patient Recording

Patient Recording - Half Speed Playback

Position

The patient's position should be supine.

Listening Tips

Diastole:Snap early in diastole, higher-pitch than S2

Waveform (Phonocardiogram)

Observe

//embedding heart animation

An opening snap is caused by thickened valve leaflets. When they open it, produces a snapping sound. The more severe the thickening the earlier in diastole the opening snap occurs. In this example you are hearing an opening snap which occurs 75 milliseconds after the start of the second heart sound.

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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