Third Heart Sound Gallop Reference Guide.
Third Heart Sound GallopA third heart sound occurs early in diastole. In young people and athletes it is a normal phenomenon. In older individuals it indicates the presence of congestive heart failure. The third heart sound is caused by a sudden deceleration of blood flow into the left ventricle from the left atrium. In the anatomy video you will see a thin-walled, dilated left ventricle with generalized decreased vigor of contraction. In the presence of a third heart sound (S3) the first heart sound is decreased in intensity while the second heart sound is increased in intensity. The third heart sound is a low frequency sound best heard with the bell of the stethoscope pressed lightly on the skin of the chest.
Auscultation Sound From Lesson
Patient Recording - Half Speed Playback
The patient's position should be supine.
Listening TipsS1: Reduced intensity
S2: Increased intensity
Diastole: S3 early in diastole, low pitched, heard during expiration
Third Heart Sound Gallop - Reference Page