Physiologic Third Heart Sound Lesson
The patient was supine during auscultation.
Description
The third heart sound (S3) can be heard early in diastole. Along with the first and second heart sounds, this extra sound creates a gallop cadence and sounds like Kentucky. The second heart sound is unsplit in this recording so that S3 is easier to hear.
Use the stethoscope bell at the apex because the third heart sound has a very-low frequency. If the patient lies on her left side, S3 will usually be louder.
The third heart sound is normal in children and young adults. Women lose S3 in their thirties, while men lose S3 in their twenties. After these ages, S3 can indicate heart disease, except for adults active in sports or fitness.
Phonocardiogram
Anatomy
Physiologic Third 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
- 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
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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
