NEW DEVELOPMENTS AND TREATMENT STRATEGIES IN PATIENTS WITH SUPRAVENTRICULAR TACHYARRHYTHMIAS

The mechanisms, clinical presentation and therapy of supraventricular tachycardias are discussed. The therapy has changed from palliation by means of anti-arrhythmic drugs into definitive cure by ablation of th e arrhythmia substrate. Radiofrequency energy causes tissue damage by heating and appears to be a safe method for catheter ablation of supra ventricular tachycardias. We report a 97% success rate for radiofreque ncy ablation of 195 accessory atrioventricular pathways thereby curing these patients from circus-movement tachycardia and paroxysmal atrial fibrillation. Complications occurred in 3% of patients. One hundred s eventy-two patients with atrioventricular nodal reentrant tachycardia, caused by reentry within dual AV-nodal pathways, were treated by sele ctively ablating one of the pathways with non-inducibility of the arrh ythmia afterwards in 97% of the cases. Nine percent of patients had a recurrence but were succesfully treated in a second session. The proce dure was complicated by complete AV-block in 4% of patients. The disap pointing medical treatment of atrial fibrillation and the fact that at rial fibrillation can be the cause of a reversible form of heart failu re (tachycardiomyopathy), induced the clinical application of alternat ive forms of treatment. Ablation of the normal atrioventricular conduc tion system by using radiofrequency energy was performed with a 100% s uccess rate in 121 patients. After implantation of a ventricular pacem aker it is possible to control and regularize the ventricular rhythm l eading to rate control and amelioration of ventricular performance.