Fourth Heart Sound Lesson #637
The patient was supine during auscultation.
Description
The fourth heart sound occurs in late diastole, just prior to the first heart sound. The fourth heart sound is a low-frequency sound best heard with a chestpiece bell pressed lightly onto the skin.
The fourth heart sound occurs during the diastolic filling phase, created by increased stiffness of the left ventricle, decreased ventricular compliance, or by increased volume. This may be a manifestation of heart disease. A fourth heart sound is never heard with atrial fibrillation because the contraction of the atria is ineffective in this condition. Review the anatomy video for an example.
The first heart sound is decreased in intensity and the second heart sound is increased in intensity.
Phonocardiogram
Anatomy
Fourth Heart Sound
Authors and Sources
Authors and Reviewers
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Heart sounds by Dr. Jonathan Keroes, MD and David Lieberman, Developer, Virtual Cardiac Patient.
- Lung sounds by Diane Wrigley, PA
- Respiratory cases: William French
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David Lieberman, Audio Engineering
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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.
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Last Update: 11/10/2021
Sources
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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
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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
