Ventricular fibrillation as its name implies, is fibrillation of the ventricle analogous to that of the auricle, but the condition is rarely observed as it is incompatible with life. It has been shown that hearts at the time of death at times enter a state of fibrillation of the ventricles and that cases of sudden death may be due to this condition. Recently G. Canby Robinson[12] has seen and made electrocardiograms of a case of ventricular fibrillation. (Fig. 44.) The case was that of a woman forty-five years old, "who had a series of attacks of prolonged cardiac syncope, closely resembling Stokes-Adams syndrome, from which she recovered." During an attack of unconsciousness in which there was no apex beat for about four minutes, the electrocardiogram was taken. Following this the tracings showed an almost regular heart beating at the rate of 85 to 100 per minute. The patient had three convulsions and died with edema of lungs about 30 hours after the attack of ventricular fibrillation.
Fig. 44.—Upper curve. Record obtained during period of cardiac syncopy at 2:48 p.m., Lead II. Lower curve from dog. Ventricular fibrillation observed in the exposed heart. Lead from right foreleg and left hind leg. (Courtesy of Dr. G. C. Robinson.)
Autopsy revealed chronic fibrous endocarditis of aortic and mitral valves, arteriosclerosis, bilateral carcinoma of the ovaries, and signs of general chronic passive congestion.
It is possible that the syncopal attacks in this case were the result of sclerosis of the vessels supplying the heart muscle although careful microscopical examination did not throw much light on the ultimate cause.
Extrasystole
Whenever there is a dropped beat or an intermittent pulse one may be sure that it is the result of an extrasystole. Such extrasystoles are produced in the ventricle at some point other than the regular path of conduction of impulses. The extrasystole may have its origin in either the auricle or the ventricle. If there is auricular extrasystole it can not usually be recognized except by graphic methods. (Fig. 45.) The ventricular extrasystole on the contrary is commonly seen and readily recognized. Most of those seen in the clinic have their origin in some part of the ventricular wall. Their two characteristics are that they occur too early and that they are followed by a pause longer than the normal diastolic pause. (Fig. 46.)
