Radiofrequency catheter ablation of tachycardia in patients with congenital heart disease

Patients with anomalies of the heart frequently suffer from arrhythmias tha t either are associated with a congenital heart defect or result from the c ourse of the disease. For most of the bradyarrhythmias, appropriate timing of the initiation of treatment is more challenging than its eventual execut ion. In the case of tachycardias, technical aspects of treatment require mo re attention because the often imperative impact such tachycardias have on quality of life, morbidity, and mortality determine intervention timing. In creasingly, interventional electrophysiology is turned to as a potentially definitive and substrate-related treatment because of antiarrhythmic drug t herapy's failure to prevent arrhythmia recurrences and the potential detrim ental side effects from drug therapy seen in this particular patient popula tion. Using the experience gained during the past 10 pears in the treatment of patients with arrhythmias but without associated structural heart disea se, several groups reported their results and difficulties with the applica tion of such therapy to patients with congenital heart defects. In this rep ort, we summarize our hospital's experience with transcatheter radiofrequen cy current application for treatment of various types of tachyarrhythmias i n 139 children and adults with congenital heart defects, emphasizing the cu rrent limitations of such therapy and addressing the potential benefits exp ected from future technology. Patient ages ranged from 5 months to 76 years (mean 25.3 +/- 17.7 years), including 56 children and adolescents less tha n 16 years of age. At least one attempt at surgical palliation or correctio n was made in 93 patients; the remaining 46 patients had no surgical interv ention attempts. A total of 225 different tachycardias were found, 93 of wh ich were based on a congenital arrhythmogenic substrate (e.g., an accessory pathway). Acquired substrates (e.g., scars or myocardial fibrosis) gave ri se to the remaining 132 tachycardias. Radiofrequency current ablation (183 sessions) successfully treated 121 of 139 patients. Within a follow-up peri od of 21 months a recurrence of the intrinsically treated tachycardia was s een in 24 patients (10.7%); 13 of the 24 underwent a successful repeat sess ion. There were no significant procedure-related complications. Young and a dult patients with congenital heart disease can be safely and successfully treated for tachycardias with the use of radiofrequency current ablation. B ecause such treatment meets the specific needs of this patient group, early consideration for this therapy is recommended.