Abstract 8279: Avoiding Cerebral Embolism during Ablation of Atrial Fibrillation by the Use of Radiofrequency Hot Balloon Catheter

Abstract

Background Cerebral Embolism (CE) is a serious complication associated with conventional radiofrequency (RF) catheter ablation of atrial fibrillation (AF). It is partly because of non-uniform heating of the tissue due to direct resistive heating by RF current under regional cooling by changeable blood flow or irrigation, resulting in thrombus formation. To avoid non-uniform heating, we have developed a RF hot balloon catheter system. Methods and Results In this RF hot balloon catheter system, the balloon could be uniformly heated at the target temperature between 60 and 65°C, as the inner fluid of the balloon was heated by RF current (1.8 MHz), and agitated by a specially designed vibration generator (Fig). The tissue in contact with the hot balloon was ablated by heat conduction, where the lesion depth was determined by the temperature of the balloon and the delivery time of RF energy. We experimentally performed pulmonary vein (PV) isolation in 10 pigs and histological examination of serial sections of the atrial lesions and the brain after ablation. There was no thrombus formation at ablated lesion and no cerebral infarction in all 10 pigs. We treated 445 patients with AF (Paroxysmal AF (PAF), n=270; Persistent AF (Per-AF), n=77; Long persistent AF (Long-AF), n=98) by PV antral isolation or box isolation ( isolation of PV and left posterior atrium) using this system and randomly performed magnetic resonance imaging (MRI) of brains in 120 patients after ablation. Within 12 months after ablation, we have no new symptom of cerebral infarction in all patients, and no CE lesion detected by Brain MRI in 120 patients. During 12 months follow up, no AF episodes were detected without anti-arrhythmic drugs in 346 patients (PAF, n=238 (88%); Per-AF, n=53 (69%); Long-AF, n=55 (56%)). Conclusion PV antral isolation or box isolation using a RF hot balloon catheter system could be performed without complication of CE and successfully treat most of the patients with AF.