Histopathologic Effects of Radiofrequency Catheter Ablation in Previously Infarcted Human Myocardium

Abstract

Catheter-based RF ablation of ischemic VT in humans causes lesions that initially resemble coagulation necrosis. This is followed by the development of an inflammatory infiltrate and, finally, the development of fibrosis. Repeated application of RF ablation may result in much larger lesions than have been previously reported.

Role of Continuous Monitoring for Optimizing Management Strategies in Patients With Early Arrhythmia Recurrences After Atrial Fibrillation Ablation

“…3 The mechanism underlying early recurrence of atrial arrhythmias (ERA) remain poorly understood but have been attributed to stimulatory effect of radiofrequency energy, imbalance in the autonomic supply of the heart, a generalized inflammatory state, and so forth, all of which are considered transient. [3][4][5] Consistent with this hypothesis, up to 60% of patients manifesting ERA eventually become arrhythmia free without needing another ablation. 1,2 Thus, at the present time it is common practice to treat ERA conservatively.…”

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

“…Cardioversion and surgical ablation-related definitions Failed electrical cardioversion Failed electrical cardioversion is defined as the inability to restore sinus rhythm for 30 s or longer following electrical cardioversion. [465,466]; (2) a transient imbalance of the ANS ultimately acting as an arrhythmia trigger [91,467]; and (3) a delayed effect of RF ablation, as previously observed with other arrhythmic substrates [467][468][469][470], likely attributable to growth or maturation of the ablation lesions in the days immediately after the procedure.…”

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…253,254,255 Although its precise mechanisms have not been fully elucidated, the possible causes include (1) a transient stimulatory effect of the tissue inflammatory response to the application of RF 256 ; (2) a transient imbalance of the ANS 257 ; and (3) a delayed effect of the application of RF, likely due to the maturation of the ablation lesion soon after the procedure. 258 A “blanking period” of 3 months after the procedure, during which reintervention should be avoided, is recommended because up to half of the patients with early recurrence remain AF-free during long-term follow-up.…”