Acute safety and efficacy of a novel multipolar irrigated radiofrequency ablation catheter for pulmonary vein isolation.

INTRODUCTION: "Single shot" ablation devices to treat symptomatic atrial fibrillation have been engineered over the last years. Safety and efficacy also includes subclinical complications only detected with esophageal endoscopy or cerebral MRI in asymptomatic patients. We studied the acute efficacy and safety profile of a novel multipolar irrigated RF ablation catheter (nMARQ™). METHODS AND RESULTS: Forty-three patients underwent pulmonary vein isolation (PVI) using the novel ablation device. Patient baseline and procedural characteristics were documented. Efficacy of PVI was identified using only the nMARQ™ catheter. All patients underwent postablation endoscopic evaluation of the esophagus to document thermal damage and cerebral MRI (diffusion weight imaging, attenuated diffusion coefficient-map) to document incidence and number of silent cerebral lesions (SCL). Effective PVI was achieved in 98% of targeted PVs in a mean procedure time of 133 minutes. A mean of 4.8, 60-second RF applications, per PV was needed for effective PVI. No clinical procedure-associated complications were noted. Esophageal temperature increase >40.5 °C was noted in 22 (51%) patients and 14 of these had thermal esophageal lesions on endoscopic evaluation. A total of 26 SCLs were noted in 14 patients (33%; 1.9/patient; mean diameter of 2.3 mm, 88% of lesions were ≤3 mm). CONCLUSIONS: PVI using the novel irrigated RF multipolar ablation device (nMARQ™) appears to be acutely effective. No clinical complications were identified. A high incidence of SCL (33%) and thermal esophageal lesions (33%) bears caution and further studies on long-term efficacy and safety are needed.

Predictors of Recurrence After Catheter Ablation of Persistent Atrial Fibrillation.

Catheter ablation of atrial fibrillation (AF) has been increasingly used to treat symptomatic patients.Within the last years a growing interest in ablation of persistent AF forms has evolved.Factors that may influence outcome of these procedures to treat persistent AF may be patient-specific (pre-procedural),procedure-related or may involve different post-ablation followup strategies. In this review potential factors predicting recurrence of AF after ablation of persistent AF have been evaluated.In essence, data is limited mostly due to incongruent definitions of persistent AF.Left atrial dimensions, duration of continuous AF and AF cycle length may be patient-specific predictors of outcome. Intra-procedural parameters involved in recurrence prediction may be extent of ablation (effective pulmonary vein isolation appears mandatory) and termination of AF during ablation. Timing and number of cardioversion if persistent AF recurs may predict outcome, as well. Many studies have identified strators for higher recurrence rates in rather small patient groups and need to be further evaluated in larger patient collectives.