Radiofrequency catheter ablation of tachycardia in patients with congenital heart disease.

Patients with anomalies of the heart frequently suffer from arrhythmias that either are associated with a congenital heart defect or result from the course of the disease. For most of the bradyarrhythmias, appropriate timing of the initiation of treatment is more challenging than its eventual execution. In the case of tachycardias, technical aspects of treatment require more attention because the often imperative impact such tachycardias have on quality of life, morbidity, and mortality determine intervention timing. Increasingly, interventional electrophysiology is turned to as a potentially definitive and substrate-related treatment because of antiarrhythmic drug therapy's failure to prevent arrhythmia recurrences and the potential detrimental side effects from drug therapy seen in this particular patient population. Using the experience gained during the past 10 years in the treatment of patients with arrhythmias but without associated structural heart disease, several groups reported their results and difficulties with the application of such therapy to patients with congenital heart defects. In this report, we summarize our hospital's experience with transcatheter radiofrequency current application for treatment of various types of tachyarrhythmias in 139 children and adults with congenital heart defects, emphasizing the current limitations of such therapy and addressing the potential benefits expected from future technology. Patient ages ranged from 5 months to 76 years (mean 25.3 +/- 17.7 years), including 56 children and adolescents less than 16 years of age. At least one attempt at surgical palliation or correction was made in 93 patients; the remaining 46 patients had no surgical intervention attempts. A total of 225 different tachycardias were found, 93 of which were based on a congenital arrhythmogenic substrate (e.g., an accessory pathway). Acquired substrates (e.g., scars or myocardial fibrosis) gave rise to the remaining 132 tachycardias. Radiofrequency current ablation (183 sessions) successfully treated 121 of 139 patients. Within a follow-up period of 21 months a recurrence of the intrinsically treated tachycardia was seen in 24 patients (10.7%); 13 of the 24 underwent a successful repeat session. There were no significant procedure-related complications. Young and adult patients with congenital heart disease can be safely and successfully treated for tachycardias with the use of radiofrequency current ablation. Because such treatment meets the specific needs of this patient group, early consideration for this therapy is recommended.