Second Heart Sounds

Second Heart Sound and Late Systolic Click | Auscultation #25 | Lesson with Audio

patient thorax when auscultating by stethoscope

The patient was supine during auscultation.

Description

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.

Phonocardiogram

Anatomy

Second Heart Sound and Late Systolic Click

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
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