Cardiac arrhythmias resulting from experimental head injury.

The cardiovascular events resulting from experimental head injury were studied to determine the incidence of cardiac arrhythmias and to define the autonomic mechanisms responsible for these changes. Electrocardiograms and arterial blood pressure were recorded in anesthetized monkeys before and after the animals were subjected to temporoparietal head impact. Cardiac arrhythmias and hypotension occurred immediately following impact in every animal studied. Various atrioventricular nodal and ventricular arrhythmias were seen. Cholinergic blockage was found to prevent arrhythmias induced by head injury whereas adrenergic blockage was found to be ineffective.