The Longer the Block, the Harder You Fall: Extrinsic Idiopathic Atrioventricular Block Masquerading as Seizures.

History and physical examination are the diagnostic cornerstones of transient loss of consciousness (TLOC). However, details can be scarce and examination unrevealing, thus making the diagnosis elusive. In a case of convulsive TLOC, the initial diagnosis was incorrect, but a fortuitously captured event on telemetry yielded the diagnosis: extrinsic idiopathic atrioventricular block. ().