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 canter and gallop are variations on the fastest gait that can be performed by a horse or other equine. The canter is a controlled three-beat gait, while the gallop is a faster, four-beat variation of the same gait. It is a natural gait pos ...
.
The normal heart rhythm contains two audible
heart sounds called S
1 and S
2 that give the well-known "lub-dub" rhythm; they are caused by the closing of
valves
A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...
in the heart. The
first heart sound
Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stet ...
(S1) is closure of the valve at the end of ventricular filling (the tricuspid and mitral valves); the
second heart sound
Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stetho ...
(S2), is closure of the aortic and/or the pulmonary valves as the ventricles relax. Extra sounds, (
third
Third or 3rd may refer to:
Numbers
* 3rd, the ordinal form of the cardinal number 3
* , a fraction of one third
* Second#Sexagesimal divisions of calendar time and day, 1⁄60 of a ''second'', or 1⁄3600 of a ''minute''
Places
* 3rd Street (d ...
and/or
fourth heart sound
The fourth heart sound or S4 is an extra heart sound that occurs during late diastole, immediately before the normal two "lub-dub" heart sounds (S1 and S2). It occurs just after atrial contraction and immediately before the systolic S1 and is cau ...
, can be normal, especially in children, or with severe exercise, but are generally heard (on the left side) when ventricular function is impaired, e.g., in case of acute infarction or severe cardiac failure. The sounds are thought to be caused by the atrium, facing back-pressure, forcing volume into an incompletely emptied ventricle. Then, given tachycardia, a "gallop" is produced. With right-sided back pressure after pulmonary embolism, and therefore an incompletely emptied right ventricle, a right-sided gallop can occur.
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 as well as
pulmonary edema
Pulmonary edema, also known as pulmonary congestion, is excessive liquid accumulation in the tissue and air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia and respiratory failure. It is due t ...
.
Gallop rhythms may be associated with the following:
* Ventricular overload
*
Sinus tachycardia
Sinus tachycardia is an elevated sinus rhythm characterized by an increase in the rate of electrical impulses arising from the sinoatrial node. In adults, sinus tachycardia is defined as a heart rate greater than 100 beats per minute (bpm). The ...
References
Further reading
* http://circ.ahajournals.org/content/20/6/1053.short - American Heart Assoc., Gallop Rhythm of the Heart
*
External links
{{Cardiovascular system symptoms and signs
Cardiology