Initial results of linear duty-cycled radiofrequency for atypical flutter and atrial tachycardia.

BACKGROUND: Duty-cycled radiofrequency (DCRF) is increasingly used for ablation of atrial fibrillation (AF). Many patients also have atrial flutter (AFL). Recently, a linear multielectrode has been shown to create linear block at the cavotricuspid isthmus and in the left atrium (LA).
OBJECTIVE: To map and ablate atypical AFL and atrial tachycardias (ATs) in the right and LA using a linear multielectrode with DCRF.
METHODS: The linear multielectrode delivers DCRF at 20-45 W maximum in 1:1 unipolar/bipolar temperature-controlled mode. Target temperatures were manually titrated to 60 °C in the LA, if power >5W indicated adequate passive cooling.
RESULTS: A total of 76 AT/AFL were targeted in 57 patients. Acute success was reached in 14/15 (93%) right AT, in 17/22 (77%) left atrial roof AFL, in 5/6 (83%) septal AFL, in 9/9 (100%) other left atrial AT, but only in 8/23 (35%) AFL from the mitral isthmus (which rose to 13/23 [57%] with additional use of irrigated radiofrequency). Nevertheless, freedom of AF/AFL 10 ± 6 months after a single procedure was documented in 92% of right AT, 71% of roof AFL, 73% for mitral AFL, and 60% of septal or other LA AT/AFL. No char formation was noted. However, frequent induction of AF and one case of asystole occurred during delivery of DCRF in a pacemaker patient.
CONCLUSION: The linear multielectrode allows mapping and ablation of atypical AFL/AT. Freedom of AF/AT was reached in 60%-92% depending on localization and number of arrhythmias. Technical modifications will improve safety and efficacy. ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.