Third Heart Sound - PhysiologicThe third heart sound is heard early in diastole. Along with the first and second heart sounds, this extra sound creates a gallop cadence and sounds like "Kentucky." In this auscultation example the second heart sound is unsplit to make it easier for you to distinguish the third heart sound. The third heart sound is very low frequency (between 25Hz and 50Hz). Listen with the bell of the stethoscope at the cardiac apex. Asking the patient to lie on his left side will frequently increase the intensity of the third heart sound. A third heart sound is heard on occasion in normal individuals with no cardiac pathology.
Half Speed Patient Sounds
The patient's position should be supine.
Diastole:S3 in early diastole. Low-pitch. Galloping (S1,S2,S3) or intermittent sound
Observe Cardiac Animation
Authors and Sources
Authors and Reviewers
- ECG heart rhythm modules: Thomas O'Brien.
- ECG monitor simulation developer: Steve Collmann
12 Lead Course: Dr. Michael Mazzini, MD.
- Spanish language ECG: Breena R. Taira, MD, MPH
- Medical review: Dr. Jonathan Keroes, MD
- Medical review: Dr. Pedro Azevedo, MD, Cardiology
- Last Update: 11/8/2021
Electrocardiography for Healthcare Professionals, 5th Edition
Kathryn Booth and Thomas O'Brien
ISBN10: 1260064778, ISBN13: 9781260064773
McGraw Hill, 2019
Rapid Interpretation of EKG's, Sixth Edition
Cover Publishing Company
12 Lead EKG for Nurses: Simple Steps to Interpret Rhythms, Arrhythmias, Blocks, Hypertrophy, Infarcts, & Cardiac Drugs
Create Space Independent Publishing
Heart Sounds and Murmurs: A Practical Guide with Audio CD-ROM 3rd Edition
Elsevier-Health Sciences Division
Barbara A. Erickson, PhD, RN, CCRN
The Virtual Cardiac Patient: A Multimedia Guide to Heart Sounds, Murmurs, EKG
Jonathan Keroes, David Lieberman
Publisher: Lippincott Williams & Wilkin)
ISBN-10: 0781784425; ISBN-13: 978-0781784429
- Project Semilla, UCLA Emergency Medicine, EKG Training Breena R. Taira, MD, MPH