Successful radiofrequency catheter ablation of right sided accessory pathways during sustained XXXX .

@entity1 @entity3153 @entity1009 @entity955
Up to now there have been no descriptions in the literature of endocardial catheter mapping and successful radiofrequency catheter ablation of the right sided accessory pathway during sustained @entity955 . We attempted ablation of a right posterolateral and a right lateral accessory pathway during sustained @entity955 with rapid anterograde conduction over the accessory pathway in two @entity1 with @entity3153 . In both @entity1 (aged 47 and 52 years), sustained @entity955 occurred during the electrophysiological study to assess accessory pathway conduction properties. The mean ventricular rate during @entity955 was 180 and 170 beats. @entity1009 , respectively. Both @entity1 were successfully ablated with a single radiofrequency impulse. At the successful ablation sites, a potential of the accessory pathway was consistently recorded preceding the onset of preexcitation in the surface electrogram, by 25 ms in @entity1 1 and 30 ms in @entity1 2. The unipolar electrogram recorded from the ablation catheter showed a QS morphology and the accessory pathway potential preceded the intrinsic deflection by 10 ms in both @entity1 . Onset of the ventricular electrogram ( @entity1 1: -20 ms; @entity1 2: -15 ms) and its activation time ( @entity1 1: -15 ms; @entity1 2: +5 ms) in relation to the onset of preexcitation in the surface electrocardiogram also indicated the close proximity of the ablation catheter to the accessory pathway. Preexcitation disappeared within 2 s after energy application in both @entity1 . Thus, radiofrequency catheter ablation of right sided accessory pathways during sustained @entity955 is feasible and may obviate the need for medical or electrical cardioversion.(ABSTRACT TRUNCATED AT 250 WORDS)
