Does the number of simultaneously activated electrodes during phased RF multielectrode ablation of atrial fibrillation influence the incidence of silent cerebral microembolism?

• Published in: Heart rhythm Vol. 10; no. 7; pp. 953 - 959
• Main Authors: Wieczorek, Marcus, MD, Hoeltgen, Reinhard, MD, Brueck, Martin, MD, FESC
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2013
• Subjects: Adult; Aged; Aged, 80 and over; Anticoagulation; Atrial Fibrillation - complications; Atrial Fibrillation - physiopathology; Atrial Fibrillation - surgery; Cardiovascular; Catheter Ablation - instrumentation; Electrodes; Equipment Design; Female; Follow-Up Studies; Germany - epidemiology; Humans; Incidence; Intracranial Embolism - epidemiology; Intracranial Embolism - etiology; Intracranial Embolism - prevention & control; Magnetic Resonance Imaging; Male; Middle Aged; Multielectrode phased ablation; Prospective Studies; Pulmonary vein isolation; Silent cerebral microembolism; Treatment Outcome; Ultrasonography, Doppler, Transcranial; Young Adult; Germany; asymptomatic cerebral embolism; magnetic resonance imaging; PVI; MRI; PV; radiofrequency; Silent cerebral microembolism; Anticoagulation; diffusion weighted; INR; international normalized ratio; PVAC; atrial fibrillation; DW; transcranial Doppler; FLAIR; Multielectrode phased ablation; fluid-attenuated inversion recovery; pulmonary vein ablation catheter; ACE; AF; pulmonary vein isolation; RF; TCD; microembolic cerebral signals; pulmonary vein; MES; Pulmonary vein isolation
• ISSN: 1547-5271; 1556-3871
• DOI: 10.1016/j.hrthm.2013.04.005

Background Asymptomatic cerebral embolus (ACE) detected by diffusion-weighted magnetic resonance imaging (DW-MRI) following atrial fibrillation (AF) ablation has been reported at varying rates with different ablation techniques. Objective To evaluate the incidence of ACE after phased radiofrequency ablation for AF with procedural modifications that potentially reduce the embolic load. Methods One hundred twenty consecutive patients with AF underwent MRI before ablation, 24 hours after ablation, and at 4–6 weeks. In all patients, simultaneous activation of pulmonary vein ablation catheter electrode pairs 1 and 5 was forbidden. While in 60 group 1 patients, a maximum of 4 electrode pairs could be activated at a time, and in 60 group 2 patients, ablation was limited to a maximum of 2 pairs. All patients were on uninterrupted phenprocoumon, with an attempted activated clotting time of >300 seconds during ablation. Results Both patient groups were comparable. A total of 28 DW-positive lesions were detected in 24 of 120 patients (20%). Seventeen group 1 patients (28.3%) were positive for new asymptomatic DW cerebral lesions compared with 7 group 2 patients (11.7%) ( P = .039). During MRI follow-up, 3 patients (2.5%) were diagnosed with a small T2-positive asymptomatic glial scar. Procedure time was longer in group 2 patients than in group 1 patients (159 ± 39 vs 121 ± 15; P < .001). Conclusions Limiting the number of simultaneously activated electrode pairs to 2 significantly reduces the rate of ACE in patients treated with a multielectrode duty-cycled phased radiofrequency catheter system for AF. This reduction corresponds with a significant prolongation of the total procedure time.