On occasion the first heart sound can be made up of two separate sounds separated by a very small interval (20-30 milliseconds).
The Mitral component (caused by closure of the Mitral valve) comes first and is louder than the Tricuspid component (caused by closure of the Tricuspid valve).
A minimally split first heart sound is a normal variation of the first heart sound.
First Heart Sound (Minimally Split) Audio
First Heart Sound (Minimally Split) Sounds
Half Speed First Heart Sound (Minimally Split) Sounds
Technique
The patient's position should be supine.
Auscultation Tips for First Heart Sound (Minimally Split)
S1:Minimal splittingSound Wave
First Heart Sound (Minimally Split) Video
Authors and Sources
Authors and Reviewers
- EKG heart rhythm modules: Thomas O'Brien.
- EKG monitor simulation developer: Steve Collmann
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12 Lead Course: Dr. Michael Mazzini, MD.
- Spanish language EKG: Breena R. Taira, MD, MPH
- Medical review: Dr. Jonathan Keroes, MD
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Heart sounds and mentorship: W. Proctor Harvey, MD
- Medical review: Dr. Pedro Azevedo, MD, Cardiology
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Last Update: 1/8/2023
Sources
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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
Dale Dublin
Cover Publishing Company -
12 Lead EKG for Nurses: Simple Steps to Interpret Rhythms, Arrhythmias, Blocks, Hypertrophy, Infarcts, & Cardiac Drugs
Aaron Reed
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 - Clinical Heart Disease
W Proctor Harvey, MD
Clinical Heart Disease
Laennec Publishing; 1st edition (January 1, 2009) -
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
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