[Atrial fibrillation induced by massage of the carotid sinus in patients with orthodromic reciprocal supraventricular tachycardia and Wolff-Parkinson-White syndrome].

A 46 years old man with WPW syndrome, due to a posteroseptal accessory pathway, was admitted because of orthodromic reciprocating tachycardia, 210/m'in frequency. At the end of the carotid sinus massage, for accomplish the conversion of tachycardia to sinus rhythm, the orthodromic reciprocating supraventricular tachycardia degenerated into atrial fibrillation associated with high ventricular rate and the presence of hemodynamic instability, reverted to sinus rhythm by intravenous propafenone. Vagal stimulation, induced by carotid sinus massage, probably caused dispersion of atrial refractorines and intraatrial reentry, converting the orthodromic tachycardia into atrial fibrillation. The transesophageal electrophysiologic study, executed in treatment with propafenone, not documented the accessory connection and atrial fibrillation or reciprocating tachycardia were not inducible.