Ebstein's anomaly in adults. Arrhythmias: diagnosis and therapeutic approach.

UNLABELLED: Patients with Ebstein's anomaly (M.E.) are known to have a high potential for developing arrhythmia, in the vast majority, of the tachycardia type. Most of these tachycardias are based on accessory pathways (AP) located along the anomalous atrioventricular valve, found in up to 30% of this patient cohort. Next to this main representative for congenital arrhythmogenic substrates, various types of acquired tachycardia were found in patients with M.E., such as atrial ectopic tachycardia (AET), atrial flutter (A. Flutt.), atrial reentry tachycardia (ART), atrial fibrillation and ventricular tachyarrhythmia. Refractoriness to medical treatment and a higher potential for side effects in these patients resulted in an increasing referral to interventional electrophysiology recent years. A total of 37 patients with M. E. and tachycardia underwent an attempt for radiofrequency current (RFC) treatment at our institution, 30 of whom were adults aged 18 to 61 yrs (33 +/- 12.2. yrs). Just 4 patients under went surgery for reconstruction of the anomalous valve and closure of an ASD (2 patients), in whom a total of 6 cases of atrial tachycardia were found, 3 common A. Flutt. and 3 atriotomy-scar related ART. Of the 26 unoperated patients, one presented with typical AV-nodal reentry tachycardia and the remaining patients with atrioventricular reentry tachycardia, based on a total of 39 APs. 27/39 Aps had bidirectional conduction properties, causing the WPW syndrome in 16 patients, 8 APs were concealed and the remaining 4 were Mahaim fibers. Within 39 sessions, 26 of the 30 patients were successfully treated by RFC ablation of the arrhythmogenic substrates. Mean session duration lasted for 313 +/- 151 min (range 95 to 660 min), and a fluoroscopy time of 56.0 +/- 38.4 min (2.2 to 146.8 min) was required. There were no severe acute complications.

CONCLUSIONS: In patients with M. E. not only a high potential for the development of tachycardia, but also a tendency towards multiple arrhythmogenic substrates in the single patient can be ascertained. RFC ablation can be used safely and effectively for treatment for various types of tachycardias in patients with M. E.. Such therapy carries the potential for a definitive treatment and should be taken early into consideration as it meets the requirements this patient cohort.