Entry- and Exit Block Demonstrated by Rythmia™ Mapping Before and After Ablation through a Thermoreactive Implant into the Superior Vena Cava of Swine

Introduction: Atrial fibrillation is the most common arrhythmia in adults. Current therapies are hampered by high complication and recurrence rates. We investigated a thermo-reactive implant using contactless energy transfer to isolate pulmonary veins in pigs.

Methods: Nitinol self-expanding implants with a dedicated ring were positioned in the superior vena cava of pigs. Using electromagnetic wireless energy transfer principles, implants were heated in a controlled fashion. Using Rythmia mapping system, signals were checked before and after the ablation, and entry- and exit block were demonstrated.

Results: 7 animals were treated. Implantation and wireless energy transfer were performed in all animals. One animal died of perforation of the superior vena cava. Five animals showed succesfull entry and exit block, one animal had an incomplete block

Conclusion: Wireless energy transfer to a nitinol implant in the vena cava of swine is feasible. We demonstrate that the dedicated ring of the implant can be heated without effect on the overall tissue, and that local ablation can thus be performed. This ablation led to bidirectional block in the majority of cases. This opens pathways for treatment of the pulmonary veins. Safety issues need to be adressed since one animal died.