First Heart Sound (Markedly Split)

If the splitting of the first heart sound is large (about 50 milliseconds), it is an indication of an abnormal condition called Right Bundle Branch Block. The splitting is most clearly heard at the tricuspid area. In the mitral valve area, the mitral component is louder. At 50 milliseconds, the splitting of the first heart sound is clearly audible.

Auscultation Sounds

Position

The patient's position should be supine.

Listening Tips

S1:Splitting.
Features:Auscultate this sound over tricuspid and mitral areas

Waveform (Phonocardiogram)

Observe

//embedding heart animation

Authors

These authors contributed the audio recordings and text found in this reference guide: Jon Keroes, MD,Diane Wrigley, PA, and David Lieberman.
Medically reviewed by Dr. Barbara Erickson, PhD, RN, CCRN.

Sources

Heart Sounds and Murmurs Across the Lifespan (with CD)
by Dr Barbara Ann Erickson
Publisher: Mosby
ISBN-10: 0323020453; ISBN-13: 978-0323020459
Heart Sounds and Murmurs: A Practical Guide with Audio CD-ROM 3rd Edition
Elsevier-Health Sciences Division
Barbara A. Erickson, PhD, RN, CCRN
Heart Sounds Made Easy with CD-ROM: (with CD-ROM) 2nd Edition
Anthony P. Salmon
ISBN-13: 978-0443069079
NCBI Review of Heart Sounds and Murmurs: A Practical Guide
The Virtual Cardiac Patient: A Multimedia Guide to Heart Sounds And Murmurs Jonathan Keroes, David Lieberman
Publisher: Lippincott Williams & Wilkin)
ISBN-10: 0781784425; ISBN-13: 978-0781784429
Ventricular Function Curves in the Exercising Dog
JONATHAN KEROES , ROGER R. ECKER , and ELLIOT RAPAPORT
Circulation Research, Vol. 25, No. 5
Electrocardiographic changes associated with ritodrine-induced maternal tachycardia and hypokalemia
American Journal of Obstetrics Gynecology, VOLUME 154, ISSUE 4, P921-923, APRIL 01, 1986
Susan K Hendricks, MD, Jonathan Keroes, MD, Michael Katz, MD
A Multimedia Guide to Heart Sounds and Murmurs
January 2007 JAMA The Journal of the American Medical Association 297(2):217-218
DOI:10.1001/jama.297.2.217. M. Saleem Seyal, MD, Reviewer

Sources

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
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 Stevben Lehrer, MD

Return to Reference Guide Index Page