Laryngocardiac Reflex: A Case Report and Review of the Literature

The vagus nerve has sensory and motor function in the larynx, as well as parasympathetic function in the thorax and abdomen. Stimulation of the superior laryngeal nerve can cause reflexive bradycardia.

We describe a case of a 45-year-old man with pre-syncopal symptoms while exercising, and bradycardia found during cardiology workup. Radiography and flexible laryngoscopy showed evidence of a right-sided, vascular laryngeal mass. Exercise testing before and after superior laryngeal nerve block showed reversal of the symptoms with the block. Subsequent resection of the lymphovascular malformation with CO₂ laser eliminated the patient's symptoms.

This is the first case reported of the laryngocardiac reflex producing symptomatic bradycardia as a result of exercise-induced engorgement of a supraglottic lymphovascular malformation, which was then cured by surgical excision. We discuss this case and the literature regarding lymphovascular malformations in the airway and the neural pathways of the laryngocardiac reflex.