Ablación de taquicardias auriculares macroreentrantes en pacientes con cardiopatías congénitas. Características y predictores de recurrencia

Abstract

Early diagnosis and improvement in surgical techniques of patients with congenital heart disease have provided a significant increase in its survival. This lower early mortality has led to an increase in the incidence of new complications in adult life of these patients. One of the most important complications is atrial re-entrant tachycardia (ART) secondary to atrial surgical scars and/or areas of fibrosis that facilitate slow intra-atrial conduction which is in turn basic mechanism of atrial re-entry. These patients can present both cavotricuspid isthmus (CTI) dependent ART and ART dependent on other atrial areas. These arrhythmias, unlike the general population, are associated with increased mortality in this population and also with higher rate of stroke and heart failure. Although the first line treatment is radiofrequency ablation, the acute and long-term success rate is lower than in the general population._x000D_ The aim of this study is to know the most common mechanisms of TAM in patients with congenital heart disease, predictors of severity and predictors of acute efficacy of ablation and maintenance of sinus rhythm. In our study population of 94 patients, 51% have only CTI related ART, 21.3% non-CTI dependent ART and 27.7% both types of ART. Detailed characteristics and illustrative activation maps are presented in the study. The highest complexity of the cardiac disease and ECG not suggestive of CTI-dependent ART during tachycardia are factors related to a higher proportion of non-ICT dependent ART. In 40% of the patients ART was accompanied by severe symptoms and up to 22% these symptoms were the first clinical ART manifestation. The great vessels transposition (GVT) cardiac disease and severe dilatation of the right atrium were associated with a greater likelihood of severe events. The acute success rate of the first ablation procedure was 74%. Predictors of acute lack of efficacy are GVT, previous atrial fibrillation, non-CTI dependent ART (whether presented isolated or associated with CTI-dependent ART) and systemic ventricular dilation. Finally, the rate of maintenance of sinus rhythm after the last ablation procedure with an average follow-up of more than 24 months is 78.3%, but rises to 87% if we exclude patients with only atrial fibrillation and non ART during follow-up. Factors related to loss of sinus rhythm are the presence of ART not ablated in the first procedure, no effective ablation in the first procedure, non-CTI dependent ART, atrial fibrillation (clinical or induced in any ablation procedure) and PR interval> 200 msec. These last tow factors have not been previously described in the literature. _x000D_ In summary, this study describes mechanisms of ART in patients with congenital heart disease and identifies predictors of non-CTI related ART, probability of severe clinical event, predictors of acute success and predictors of arrhythmia recurrence in long-term follow-up.

Date of Award	16 Nov 2016
Original language	Spanish
Awarding Institution	Vall d'Hebron University Hospital (HUVH)
Supervisor	Angel Moya Mitjans (Director), Jaume Casaldaliga Ferrer (Director) & Antonio David Garcia Dorado García (Tutor)