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 tab.

After reviewing the sound, use the waveform and anatomy tabs for more information about this sound.

First Heart Sound - Decreased Intensity
Position: Mitral
Maneuver: Supine
Chestpiece: Diaphragm