Third Heart Sound (S3) Gallop
Virtual Auscultation
The patient's position is supine.
Lesson
A third heart sound (S3) occurs early in diastole. In young people and athletes it is a normal phenomenon. In older individuals it indicates the presence of congestive heart failure. The third heart sound is caused by a sudden deceleration of blood flow into the left ventricle from the left atrium. In the anatomy video you will see a thin-walled, dilated left ventricle with generalized decreased vigor of contraction. In the presence of a third heart sound (S3) the first heart sound is decreased in intensity while the second heart sound is increased in intensity. The third heart sound is a low frequency sound best heard with the bell of the stethoscope pressed lightly on the skin of the chest.Waveform
Heart Sounds Video
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: 12/11/2022
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)
