Swallowing-induced atrial tachycardia arising from superior vena cava: Significant involvement of parasympathetic nerve activity

A 64-year-old man who complained of palpitations brought on by swallowing was found to have short runs of paroxysmal supraventricular tachycardia (SVT) induced by swallowing. Electrophysiology studies suggested that the SVT was an automatic atrial tachycardia. An esophageal manometric study demonstrated that the tachycardia was coincident with relaxation of the upper esophageal spincter and preceded peristaltic activity in the esophageal body. Atropine and bethanechol did not affect the swallow-induced tachycardia. The patient's symptoms were controlled by verapamil and quinidine. After five months, these medications were discontinued, with no recurrence of symptoms. Based on analysis of ten prior cases and the present case, it appears that swallow-induced SVT generally occurs in men between the ages of 45-75 years who have no evidence of structural heart disease or an esophageal disorder. The SVT is usually either a nonsustained automatic atrial tachycardia or atrial fibrillation. The mechanism is conjectural, but the most likely possibility is a vagally-mediated neural reflex, probably involving a neurotransmitter other than acetylcholine.

A 47-year-old man underwent slow pathway ablation for slow-fast atrioventricular nodal reentrant tachycardia. Following the procedure, he felt palpitations while swallowing, and swallowing-induced atrial tachycardia was diagnosed. Swallowing-induced atrial tachycardia arose from the right atrium-superior vena cava junction and was cured by catheter ablation. After the procedure, the patient's heart rate variability changed significantly, indicating suppression of parasympathetic nerve activity. In this case, swallowing-induced atrial tachycardia was related to the vagal nerve reflex. Analysis of heart rate variability may be helpful in elucidating the mechanism of swallowing-induced atrial tachycardia.

We present a case of a 49-year-old man who experienced invariably reproducible paroxysmal supraventricular tachycardia during swallowing. Because beta-blockers and multiple antiarrhythmic drugs failed to prevent the episodes of this tachycardia, we performed catheter mapping and ablation. After placing multiple decapolar catheters, when the patient swallowed a few sections of an orange, intracardiac mapping revealed atrial premature beats and atrial tachycardia that lasted for a few seconds and arose from an ostial site of the right superior pulmonary vein. After the right superior pulmonary vein antrum was completely isolated, the patient became free from the swallowing-induced tachycardia.