Excessive vagal response during left atrial ablation in a patient with paroxysmal atrial fibrillation.

Vagal reflexes can be induced by stimulation of select epicardial and endocardial areas of the left atrium. The present report describes the case of a 54-year-old woman with a history of recurrent symptomatic episodes of paroxysmal atrial fibrillation. During radiofrequency application around the left superior pulmonary vein, the patient exhibited an excessive vagal response with a sinus pause of 17 s.