First Heart Sound - Decreased Intensity
First Heart Sound - Decreased Intensity
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.Auscultation Sounds
Position
The patient's position should be supine.
Listening Tips
S1:Reduced intensityWaveform (Phonocardiogram)
Observe
//embedding heart animation
A decrease in the vigor of contraction of the left ventricle causes decreased intensity first heart sound.
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.
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