Silva et al Catheter ablation of atriofascicular Mahaim fibers

Objective- To determine whether recording of the activation potential may be used as an isolated criterion to guide catheter ablation of atriofascicular Mahaim fibers. Methods- We studied 6 patients (5 females, mean age of 26±7.3 years) with paroxysmal tachycardias with a wide QRS complex, whose electrophysiological study diag-nosed atriofascicular Mahaim fibers. Mapping and cathe-ter ablation were performed in sinus rhythm, guided only by the recording of the activation potential of the fiber. Results- Efficacy in ablation was achieved in all patients. The fibers were located in the right lateral region of the tricuspid ring in 3 patients, right posterola-teral region in 2, and right anterolateral region in 1. A mean of 5.3±3 radiofrequency applications was perfor-med. The mean fluoroscopy time was 46.6±25 minutes, and the mean duration of the procedure was 178.6±108 minu-tes. No complication occurred. In a mean 20-month follow-up, all patients were asymptomatic and receiving no anti-arrhythmic drugs. Conclusion- Catheter ablation of Mahaim fibers may be performed with good safety and efficacy by mapping the activation potential of the tricuspid ring in sinus rhythm