[10 years radiofrequency ablation of accessory conduction pathways]

Catheter ablation of the preexcitation syndrome is a curative treatment. Accessory pathways between structures of the specific conduction system or working myocardium are morphologic prerequisites for orthodromic or antidromic reentrant tachycardia of various frequency, duration, and rate. Detection of mechanisms of tachyarrhythmias and understanding the role of accessory pathways in tachycardia, mapping of accessory connections, function of nodal conduction system, and additional accessory pathways are necessary for successful catheter ablation. Anomalies of the tricuspid valve and coronary sinus and concomitant disease of the heart should be investigated prior to catheter ablation using echocardiography and contrast injection. Different variations of the preexcitation syndrome and the results of catheter ablation in 300 patients are demonstrated. Catheter ablation is indicated in refractory tachyarrhythmias on the basis of accessory pathways. The treatment is performed in a catheterization laboratory by two highly experienced cardiologists in the field of electrophysiology after training in 100 procedures. The investigators need experience in interventional treatment of coronary artery disease, in transseptal puncture, and in the management of complications (coronary and valvular problems, thromboemboly, and pericardial drainage). Catheterization needs careful protection of radiation. An ablation is possible at an atrial or ventricular insertion site of the accessory pathway or in between. Ablation is done during sinus rhythm, atrial stimulation, antidromic reentry, or atrial fibrillation or during ventricular pacing and orthodromic tachycardia. The procedure should end with bidirectional block of the accessory pathway in 90-95% of the patients. Complications occur in 2-4% of procedures. Recovery of accessory conduction is observed in 8%. Catheter ablation of the accessory pathway is the treatment of first choice in symptomatic patients with the pre-excitation syndrome. The procedure has limited risks and a high success rate.