CONSISTENT SPATIOTEMPORAL VECTORS IN ATRIAL FIBRILLATION PREDICT RESPONSE TO ABLATION

Prasanth Ganesan, Neal K Bhatia, Thomas C Beck, Namita Ravi, Albert J Rogers, David Krummen, Paul J Wang, Wouter-Jan Rappel, Sanjiv Narayan

Abstract:

Background

It is unclear which mechanisms influence successful ablation for persistent atrial fibrillation (AF). Since AF is easier to treat when it is more organized in time (more regular and slower), we hypothesized that spatiotemporally organized AF would predict ablation response.

Methods

In n=102 AF patients (age 62±10 yrs, 79% male), n=49 had termination by ablation (“Term”), and n=53 were “Non-term”. Basket catheters (64 poles) recorded unipolar electrograms. Ablation targeted localized rotational/focal regions, then pulmonary vein isolation. Wavefront flow fields (WFF) of AF propagation were calculated each 1 ms. Spatiotemporal AF consistency (STAC) was calculated as the dot product of WFF to a reference, over time.

Results

Fig A shows organized AF vectors (left) that were consistent over 1 min (right) with a mean STAC of 0.7±0.1. Fig B shows organized AF vectors (left) that were not consistent over time (right; 0.2±0.2). STAC was higher in Term than in Non-term groups (0.42±0.27 vs 0.31±0.20, p=0.03, Fig C). Term patients had a bimodal distribution, with 32.6% having STAC≥0.5 vs 11.3% for Non-term (p=0.01). Positive and negative predictive values of STAC≥0.5 for AF termination were 72.7%, and 58.8%, with specificity 88.7%, sensitivity 32.6%, exceeding clinical risk scores.

Conclusion

Persistent AF shows consistent global activation for tens of seconds. Higher consistency predicted AF termination by ablation. Future studies should refine this index and identify its mechanistic bases.