A 71-year-old man presented with a 6-month history of fainting. Consciousness was quickly regained without clouding or confusion. Ancillary investigations were inconclusive and he was treated with carbamazepine. The fainting spells did not cease and he was referred for a tilt-table test exam. In the head-up position (table tilted at 60°), massage of the carotid sinus was immediately followed by asystole, unconsciousness, and a sharp drop in arterial pressure for 5 seconds. The same procedure in the lying position did not elicit clinical symptoms or hæmodynamic imbalance. A diagnosis of carotid sinus hypersensitivity with a cardio-inhibitory response pattern was made. Carbamazepine was withdrawn and a double-chamber pacemaker was implanted in his right ventricle. He remained symptom-free for the ensuing 18 months. This case supports the diagnostic utility of carotid sinus massage during the head-up tilt test in patients with unexplained non-convulsive loss of consciousness.
syncope; faintness; carotid sinus hypersensitivity; tilt test
