Swallowing-induced tachycardia; three modalities of autonomic nervous effects.

Three cases are reported who have short runs of atrial premature contractions (APCs) induced by swallowing and cough. The occurrence of the APCs were affected by autonomic nervous system in all cases. The precipitating factor is considered to be the increase of vagal tone in case 1, sympathetic tone in case 2 and both of them in case 3. The autonomic mechanism of swallowing-induced tachycardia could be divided into three categories and the treatment of these arrhythmias might be different in each group. Pharmacological autonomic blockade with atropine and propranolol is useful to reveal the underlying autonomic mechanisms.