Gallop rhythm

Overview
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.

Associated conditions
Gallop rhythms may be heard in young or athletic people, but may also be a sign of serious cardiac problems like heart failure.