Persistent atrial fibrillation associated with syncope due to orthostatic hypotension: a case report.

A 40-year-old man was referred to our Cardiology Unit because of three syncopal episodes. The ECG showed atrial fibrillation with a mean heart rate of 104 bpm. The patient was unable to maintain the upright position because of marked orthostatic hypotension associated with bradycardia and presyncope. Two days later the patient underwent direct current shock with sinus rhythm restoration. After the procedure both symptoms and orthostatic hypotension disappeared. A tilt test induced marked hypotension and bradycardia only after nitroglycerine. This is the first report of a patient with persistent atrial fibrillation associated with syncope caused by orthostatic hypotension and bradycardia. The patient's clinical features and positive tilt test only after nitroglycerine lead us to hypothesize that the arrhythmia plays a more important role in the etiology of symptoms with respect to autonomic impairment and that the pathophysiological mechanism responsible for these symptoms could be mainly the baroreceptor reflex.