Clinical and electrophysiologic characteristics of patients with antidromic circus movement tachycardia in the Wolff-Parkinson-White syndrome.
 Antidromic circus movement tachycardia was documented in 36 of 345 consecutive patients with Wolff-Parkinson-White syndrome undergoing detailed electrophysiologic evaluation.
 Twenty-six patients were men and 10 were women (mean age +/- standard deviation 26 +/- 12 years [range 12 to 45]).
 Multiple accessory pathways were identified in 12 of these 36 patients (33%).
 Ten of the patients (67%) with clinically documented antidromic tachycardia had multiple accessory pathways.
 Dizziness and syncope occurred in 61 and 50% of patients with antidromic circus movement tachycardia.
 Six patients had clinical documentation of atrial fibrillation, and 4 patients (11%) were resuscitated from ventricular fibrillation.
 In the 36 patients, 56 distinct antidromic tachycardias were recorded and several different pathways were observed.
 Orthodromic tachycardia was the most frequently associated arrhythmia (72%).
 Dual atrioventricular nodal pathways were present in 12 patients (33%); however, atrioventricular nodal tachycardia could be initiated in only 2 of them.
 Interruption of the accessory pathway was successfully performed in all 20 patients undergoing surgery.
