What is the cause of syncope?

A 64-year-old man with severe ischemic cardiomyopathy, who also had permanent atrial fibrillation (AF) for over a year, presented with sudden loss of consciousness. The patient had no prior episode of syncope. He denied prodromal symptoms. The patient did not remember how long he was unconscious. He suffered facial and spinal cord contusions but no fractures. The patient had a prophylactic biventricular pacemaker and cardioverter-defibrillator (ICD) implanted 2  years before but after spontaneous recovery from the episode of syncope, he did not report experiencing an ICD shock.
Source: Journal of Electrocardiology - Category: Cardiology Authors: Source Type: research