Cardiac electrophysiology of patients with spinal cord injury.

Spinal cord injury is a clinical syndrome encountered frequently in trauma centers and is accompanied by both acute and chronic heart rhythm abnormalities. The injury is characterized by sympathetic nervous system impairment with preservation of parasympathetic output via the vagus nerve. Severe bradycardia in the form of life-threatening sinus arrest or complete heart block may be observed in the acute recovery phase. Therapy for arrhythmias in the acute phase includes atropine, intravenous chronotropes, methylxanthines for the prevention of episodic bradycardia, and pacemaker implantation in severe cases. In the chronic recovery phase, autonomic dysreflexia in the form of paroxysmal hypertension is often induced by visceral organ distension or other stimuli and can be accompanied by bradycardia or tachycardia. The prognosis for survivors of spinal cord injury is expected to improve with further advances in surgical and medical care, and electrophysiologists will likely be called upon more frequently to help manage heart rhythm disorders in this setting.