First Heart Sound - Decreased Intensity | Auscultation #17 | Lesson with Audio
Where to Auscultate
 
            
The patient was supine during auscultation.
Description
A decreased intensity first heart sound can be produced by various heart abnormalities, such as a viral infection of the heart called a cardiomyopathy. Other conditions include a previous heart attack and decreased thyroid function. The decreased intensity first heart sound is due to a decrease in the vigor of contraction of the left ventricle. See the anatomy video.Phonocardiogram
Anatomy
First Heart Sound - Decreased Intensity
A decrease in the vigor of contraction of the left ventricle causes  decreased intensity first heart sound.
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
- 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




