Normal Heart Sounds

Loud First Heart Sound Lesson #660

patient thorax when auscultating by stethoscope

The patient was supine during auscultation.

Description

The first heart sound is usually slightly louder than the second when auscultating at the mitral valve (apex).

The first heart sound is much louder than the second heart sound in this case. A thickened but still movable mitral valve is generating this particular sound. Look at the anatomy video to see the thickened mitral valve leaflets.

Loud first heart sounds can also be observed in patients with thin chests.

Phonocardiogram

Anatomy

Loud First Heart Sound

Notice the thickened mitral valve leaflets. The first heart sound is much louder than the second heart sound. This can be produced by a thickened, but still mobile, mitral valve.

Authors and Sources

Authors and Reviewers

Heart sounds by Dr. Jonathan Keroes, MD and David Lieberman, Developer, Virtual Cardiac Patient.
Lung sounds by Diane Wrigley, PA
Respiratory cases: William French
David Lieberman, Audio Engineering
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.
Last Update: 11/10/2021

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 Steven Lehrer, MD
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