Splitting Second Heart Sound Lesson
The patient was supine during auscultation.
Description
When the aortic and pulmonic valves close, sounds are created. Normally a combined sound is heard, which is the second heart sound (S2). If these two components can be individually distinguished, the condition is called a physiological split.
Careful analysis of the splitting and intensity of the second heart sound can indicate the presence of many cardiac abnormalities.
While listening to the audio recording, observe that splitting varies between zero and eighty milliseconds depending on the respiratory cycle phase.
In physiologic splitting, the maximum separation between aortic and pulmonic components of the second heart sound occurs at peak inspiration.
In paradoxical splitting, the maximum separation occurs at peak expiration. Paradoxical splitting can occur with left bundle-branch block (LBBB) and aortic stenosis, both of which cause the aortic valve closure to be delayed until after the pulmonic valve closure, reversing the normal sequence of events.
Phonocardiogram
Anatomy
Splitting 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
- 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
