Second Heart Sounds

Opening Snap and S2 Lesson #674

patient thorax when auscultating by stethoscope

The patient was supine during auscultation.

Description

In this recording, listen for an opening snap that begins about 75 milliseconds after the commencement of S2. Such opening snaps in early in diastole and a single S2 can mimic a split second heart sound.

The source of an opening snap is thickened valve leaflets which produce a snapping sound when opening. The more severe the thickening the earlier in diastole the opening snap occurs.

Phonocardiogram

Anatomy

Opening Snap and S2

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 and Sources

Authors and Reviewers

Heart sounds by Dr. Jonathan Keroes, MD and David Lieberman, Developer, Virtual Cardiac Patient.
Lung sounds by Diane Wrigley, PA
Respiratory cases: William French
David Lieberman, Audio Engineering
Heart sounds mentorship by W. Proctor Harvey, MD
Special thanks for the medical mentorship of Dr. Raymond Murphy
Reviewed by Dr. Barbara Erickson, PhD, RN, CCRN.
Last Update: 11/10/2021

Sources

Heart and Lung Sounds Reference Library Diane S. Wrigley
Publisher: PESI
Impact Patient Care: Key Physical Assessment Strategies and the Underlying Pathophysiology
Diane S Wrigley & Rosale Lobo
Practical Clinical Skills: Lung Sounds
Essential Lung Sounds Diane S. Wrigley, PA-C
Published by MedEdu LLC
PESI Faculty - Diane S Wrigley
Case Profiles in Respiratory Care 3rd Ed, 2019
William A.French
Published by Delmar Cengage
Essential Lung Sounds by William A. French
Published by Cengage Learning, 2011
Understanding Lung Sounds Steven Lehrer, MD
Clinical Heart Disease W Proctor Harvey, MD
Clinical Heart Disease
Laennec Publishing; 1st edition (January 1, 2009)
Heart and Lung Sounds Reference Guide
PracticalClinicalSkills.com