Do the ongoing rhythm and target vein during energy delivery affect microembolic signal generation during PVAC ablation for atrial fibrillation?
During PVAC ablation for atrial fibrillation, ablating left-sided pulmonary veins and ablating during atrial fibrillation at temperatures >56°C significantly increases cerebral microembolization.
BACKGROUND: Pulmonary vein isolation with phased radiofrequency current and use of a pulmonary vein ablation catheter (PVAC) has recently been associated with a high incidence of clinically silent brain infarcts on diffusion-weighted magnetic resonance imaging, and a high microembolic signal (MES) count detected by transcranial Doppler. We investigated the potential effects of the ongoing rhythm and the target vein during energy delivery (ED) on MES generation during PVAC ablations. METHODS AND RESULTS: A total of 735 EDs during 48 PVAC ablations were analyzed. MES counts were recorded for each ED and time-stamped for correlation with the ongoing rhythm and the target vein for each ED. Significantly higher MES counts were observed during ablations of the left-sided as compared with the right-sided pulmonary veins (P = 0.0003). Similarly, higher MES counts were detected during EDs in atrial fibrillation as compared with sinus rhythm when the temperature was >56°C (P < 0.0001). The ongoing rhythm had no effect on the number of MESs at lower temperatures during ablation. CONCLUSIONS: Both the ongoing rhythm during ED and the site of ablation influence microembolus generation during PVAC ablation procedures.
Nagy-Baló et al. (Tue,) studied this question.