GALLOP RHYTHM

SALIENT FEATURES

History

· Dyspnoea and determine NYHA class.

· Paroxysmal nocturnal dysnoea.

· Swelling of the feet.

Examination

· Presence of an abnormal third or fourth heart sound with tachycardia (the presence of a normal third

or fourth heart sound does not connote a gallop rhythm unless there is associated tachycardia).

· Auscultate with the bell as third and fourth heart sounds are low pitched.

· Gallop rhythm due to third heart sound seems to sound like 'Kentucky', whereas that due to the

fourth heart sound sounds like 'Tennessee'.

Note

· A left ventricular--third heart sound is best heard at the apex, whereas the right ventricular third heart

sound is best heard along the left sternal border.

· In emphysematous patients the gallop is better heard when listening over the xiphoid or epigastric

area.

DIAGNOSIS

This patient has gallop rhythm (lesion) which indicates that he is in cardiac failure (functional status).

QUESTIONS

What is the expression used when both the third and fourth heart sounds are heard with

tachycardia ?

This is known as the summation gallop. It can sometimes be mistaken for a diastolic rumbling murmur.

ADVANCED-LEVEL QUESTIONS

What is the mechanism of production of the third heart sound?

It is caused by rapid ventricular filling in early diastole.

What is the mechanism of production of the fourth heart sound?

it is caused by vigorous contraction of the atria (atrial systole) and hence is heard towards the end of

diastole.

How do you differentiate between the fourth heart sound, a split first heart sound and an ejection

click?

The fourth heart sound is not heard when pressure is applied on the chest piece of the stethoscope, but

pressure does not eliminate the ejection sound or the splitting of the first heart sound.

What are the causes of a third heart sound?

Physiological: in normal children and young adults.

Pathological:

· Heart failure.

· kelt ventricular dilatation without failure: mitral regurgitation, ventricular septal

defect, patent ductus arteriosus.

· Right ventricular S3 in right ventricular failure, tricuspid regurgitation.

What are the implications of a third heart sound in patients with valvular heart disease?

· in patients with mitral regurgitation, they are common but do not necessarily reflect ventricular systolic

dysfunction or increased filling pressure (N Engl J Med 1992: 327: 458-62).

· In patients with aortic stenosis, third heart sounds are uncommon but usually indicate the presence

of systolic dysfunction and raised filling pressure.

What are the causes of a fourth heart sound?

Normal: in the elderly.

Pathological:

· Acute myocardial infarction.

· Aortic stenosis (the presence of S4 in individuals below the age of 40 indicates significant

obstruction).

· Hypertension. (It is a constant finding in hypertension.)

· Hypertrophic cardiomyopathy.

· Pulmonary stenosis.

Note. The fourth heart sound does not denote heart failure, unlike the S3 gallop.

Potain credited Jean Baptiste Bouillaud (1786-1881), Professor of Medicine in Paris, as being the first

person to describe gallop rhythm (Jean Baptiste Bouillaud. Proc R Sec Med 1931; 24: 1253-1931).

Pierre Carl Edouard Potain (1825 1901), Parisian physician, was the first to distinguish between various

types of gallop in a short account titled Theorie du Bruit de Gallop in 1885.