Background: Pulmonary vein isolation is associated with silent cerebral ischemic lesions detected by diffusion-weighted magnetic resonance imaging (MRI), with an incidence between 1% and 40%. Recent studies have shown that these cerebral lesions can occur after radiofrequency ablation for left ventricular extrasystole.
Objective: The aim of this study was to investigate silent cerebral ischemic lesions following left-sided conventional ablation.
Methods: In a prospective study, 296 consecutive patients scheduled for paroxysmal supraventricular tachycardia (PSVT) ablation were screened, and 26 patients meeting study criteria were enrolled. Participants underwent cerebral MRI 24 hours prior and after the ablation, in case of new ischemic lesions, a repeated MRI was planned within 3-6 months. Two sequences were used, a 3D T2-weighted fluid-attenuated inversion recovery and an axial diffusion-weighted sequence. Patients were planned to be divided into three groups: patients with and without silent cerebral ischemic lesions who underwent left-sided ablation, and a control group undergoing only right-sided ablation. Groups were compared based on clinical and procedural characteristics.
Results: The mean age was 43.9±17.3 years, 42% (n=11) were men. In all groups radiofrequency energy was used and the ablation was performed with a 4-mm tip non-irrigated catheter. Left atrium was approached by transseptal puncture controlled by intracardiac echocardiography. 14 left-sided ablations were performed including 13 left-sided pathways and 1 left-sided AVNRT ablation. None of the postprocedural MRI revealed any evidence of new cerebral ischemic lesions. Mean procedural time of left-sided ablations was 176.9±74.7 min. which was significantly longer (p=0.0077) compared to the right-sided procedures with 132±72 min. Mean left atrial procedural time was 69.1±7.8 min., average ACT was 265±28.2 seconds.
Conclusion: No silent ischemic cerebral lesions were detected by MRI after catheter ablation for left-sided PSVT substrate in comparison with the historical population undergoing ablation for atrial fibrillation or ventricular extrasystole. Presumably, cerebral lesions occur at a lower rate or might not appear at all after these less complex procedures.