Cardiac Arrhythmias, Increased Intracranial Pressure, and the Autonomic Nervous System

¹ Department of Internal Medicine, Section on Cardiology, Ochsner Clinic and Ochsner Foundation Hospital, New Orleans

Dysfunction of the autonomic nervous system has been implicated in the development of changes in electrocardiographic wave forms and cardiac arrhythmias in both patients and laboratory animals with intracranial lesions. In this study various cardiac arrhythmias occurred following a rapid increase in intracranial pressure or instantaneous release of previously elevated intracranial pressure in anesthetized dogs. Even with a modest elevation in intracranial pressure, arrhythmias occurred following injection of isoproterenol. The same dose of isoproterenol with normal intracranial pressure resulted in either no arrhythmia or one of much shorter duration. Both the administration of atropine and vagotomy eliminated or prevented arrhythmias after either an increase in intracranial pressure or a combination of an increased intracranial pressure and injection of isoproterenol. These results suggest that cardiac arrhythmias occurring with intracranial lesions may be successfully managed by appropriate pharmacologic intervention. The hazard of treating such patients with catecholamines is emphasized.