Latent Clerc-Levy-Cristesco syndrome as an electrophysiologic basis for paroxysmal reciprocal atrioventricular nodal tachycardia

An intracardiac electrophysiological investigation was performed in 15 patients with frequent episodes of supraventricular tachycardias (SVT) which are regarded, in terms of the present electrophysiological criteria, as episodes of reciprocal atrioventricular nodal tachycardia. It was demonstrated that accessory atrionodal junctions functioning only in the retrograde direction formed the basis for arrhythmias in 6 patients. This electrophysiological phenomenon was proposed to be termed the latent Clerc-Lery-Cristesco (CLC) syndrome. The main electrophysiological criteria for diagnosing the syndrome are the following: a) during a SVT episode, retrograde atrial excitation is recorded before or concomitantly with the initiation of ventricular excitation; b) during a SVT episode, H-A interval is no greater than 5 ms; c) during programmed ventricular stimulation, H2-A2 interval values remain constant. The latent CLC syndrome was shown to be commonly associated with discrete conduction in the antegrade atrioventricular junctions. Rhytmilen and gilurytmal (ajmaline) are the most potent antiarrhythmic agents for patients with reciprocal SVT due to the latent CLC syndrome.