Brain Emboli After Left Ventricular Endocardial Ablation
Background—Catheter ablation for ventricular tachycardia (VT) and premature ventricular complexes (PVCs) is common. Catheter ablation of atrial fibrillation is associated with a risk of cerebral emboli attributed to cardioversions and numerous ablation lesions in the low-flow left atrium, but cerebral embolic risk in ventricular ablation has not been evaluated.
Methods—We enrolled 18 consecutive patients meeting study criteria scheduled for VT or PVC ablation over a 9-month period. Patients undergoing left ventricular (LV) ablation were compared to a control group of those undergoing right ventricular (RV) ablation only. Patients were excluded if they had implantable cardiac defibrillators or permanent pacemakers. Radiofrequency energy was used for ablation in all cases and heparin was administered with goal activated clotting times of 300-400 seconds for all LV procedures. Pre- and post-procedural brain magnetic resonance imaging (MRI) was performed on each patient within a week of the ablation procedure. Embolic infarcts were defined as new foci of reduced diffusion and high signal intensity on fluid-attenuated inversion recovery brain MRI within a vascular distribution.
Results—The mean age was 58 years, half were men, half had a history of hypertension, and the majority had no known vascular disease or heart failure. LV ablation was performed in 12 patients (VT, n=2; PVC, n=10) and exclusively RV ablation in 6 patients (VT, n=1; PVC, n=5). Seven patients (58%) undergoing LV ablation experienced a total of 16 cerebral emboli, compared with zero patients undergoing RV ablation (p = 0.04). Seven of 11 patients (63%) undergoing a retrograde approach to the LV developed at least one new brain lesion.
Conclusions—More than half of patients undergoing routine LV ablation procedures (predominately PVC ablations) experienced new brain emboli after the procedure. Future research is critical to understanding the long-term consequences of these lesions and to determine optimal strategies to avoid them.
- Received September 16, 2016.
- Revision received November 16, 2016.
- Accepted December 21, 2016.