Abstract
The study of a large number of phonocardiograms from a series of patients with heart disease and from normal subjects suggests the tentative conclusions enumerated below. Two Einthoven galvanometers coupled in tandem were used to record the electrocardiogram and the heart sounds simultaneously and the electric stethoscope manufactured by the Western Electric Company was used to convert the sounds into electrical variations.
From the graphic standpoint gallop rhythm may be defined as a condition in which 3 sounds occur during each cardiac cycle; 3 or perhaps 4 varieties may be distinguished.
(a) Protodiastolic gallop rhythm in which the extra sound follows the second heart sound by a constant interval and occupies the same position in the cardiac cycle as the normal third heart sound.
(b) Presystolic gallop rhythm in which the extra sound precedes the first heart sound by a constant interval, and is almost certainly of auricular origin. The onset of the extra sound falls within the P-R interval of the electrocardiogram. This appears to be the most common type of gallop rhythm; it is particularly frequent in cases of arterial hypertension.
(c) Systolic gallop rhythm in which the extra sound falls within the limits of ventricular systole. This type of gallop rhythm is uncommon and apparently has no clinical significance.
(d) Gallop rhythm due to audible auricular sounds when the P-R interval of the electrocardiogram is increased beyond normal limits in which case the extra sound may fall in any part of diastole. This should probably be considered a variety of presystolic gallop rhythm since the extra sound is linked to the first heart sound which follows auricular systole by a constant interval so long as there is no dropping out of ventricular beats,
In 3 cases of bundle branch block with gallop rhythm the extra sound occurred in presystole and preceded the first heart sound by a constant interval.
Get full access to this article
View all access options for this article.