Deglutition syncope with coexistent carotid sinus hypersensitivity.

A 63-year-old man had symptomatic deglutition-induced atrioventricular (A-V) block. There was also a coexistent mixed type carotid sinus hypersensitivity presenting as A-V block. No A-V nodal dysfunction was revealed during electrophysiologic studies. The vasodepressor response to carotid massage implies a central vagal hyperresponsiveness, which can also explain the cardioinhibitory responses to swallowing and carotid sinus massage, both possibly unmasked by posterior myocardial infarction.