Possible Role of the Fear Paralysis Reflex in Sudden Cardiac Death

Abstract

Sudden cardiac death is generally assumed to be due to ventricular fibrillation occurring in a setting of coronary heart disease [11]. The role of a neural factor in the mechanism of sudden cardiac death was first advanced by Mac William in 1887 [52], who also suggested that sympathetic discharges may be the important factor in initiating the fatal arrhythmia. More recently, evidence for the participation of the brain in inducing ventricular fibrillation through sympathetic discharges in emotional stress, in many instances also in the absence of coronary disease, has in particular been provided by Lown and associates [46, 47, 49, 50, 62], Corbalan et al. [8] and DeSilva [11], although psychical factors have been given much less attention than somatic ones. The traditional somatic risk factors fail to account for half of the mortality from coronary heart disease encountered on a worldwide basis [6]. There can be no doubt that higher nervous activity frequently is implicated in the altered ventricular ectopic activity. It has been estimated that sudden cardiac death may be preceded by acute psychical disturbances in 20%–40% of cases [11, 62]. Structural damage of the heart is not a prerequisite for the occurrence of ventricular fibrillation [11]. The latter may be caused by transient impulses to the heart which momentarily disorganize cardiac electrical activity [12, 45, 47, 48]. A dominant role of the left sympathetic nerves in arrhythmogenesis and,the antifibrillatory effect on its lesioning have been well documented [66].