The nervous system and cardiac arrhythmias.

The nervous system has marked influence on the electrophysiological state of the heart and in certain circumstances may lead to serious cardiac arrhythmias. Electrocardiographic waveform abnormalities that occur in association with central nervous system disease suggest disturbances of ventricular repolarization. Disorders of ventricular depolarization have been implicated in vulnerability to and occurrence of ventricular arrhythmias, including fibrillation. Experimental studies have demonstrated localized influences of cardiac sympathetic nerves and have provided suggestive evidence that regional cardiac disorders due to inappropriate sympathetic influence occur in disease. Clinical observations suggest that such autonomic abnormalities occur in a variety of conditions, including the idiopathic prolonged QT interval syndromes, acute myocardial infarction, and in association with central nervous system disease.