Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
A gallop rhythm refers to a (usually abnormal) rhythm of the heart on auscultation. It includes three or four sounds, thus resembling the sounds of a gallop.
The normal heart rhythm contains two audible heart sounds called the first heart sound or (S1) and the second heart sound (S2) that give the well-known "lub-dub" rhythm. These two heart sounds are caused by the closing of valves in the heart.
A gallop rhythm contains another sound, called S3 or S4, dependent upon where in the cycle this added sound comes.
It can also contain both of these sounds forming a quadruple gallop, and in situations of very fast heart rate can produce a summation gallop where S3 and S4 occur so close as to be indistinguishable.
Gallop rhythms may be heard in young or athletic people, but may also be a sign of serious cardiac problems like heart failure.
- ↑ Tavel ME (1996). "The appearance of gallop rhythm after exercise stress testing". Clin Cardiol. 19 (11): 887–91. doi:10.1002/clc.4960191109. PMID 8914783. Unknown parameter
- ↑ Template:DorlandsDict
- Kuo PT, Schnabel TG, Blakemore WS, Whereat AF (1957). "Diastolic gallop sounds, the mechanism of production". J. Clin. Invest. 36 (7): 1035–42. doi:10.1172/JCI103499. PMC 1072690. PMID 13449156.