Introduction
Arrhythmias pose a significant challenge in the care of children with and without congenital heart disease (CHD), leading to increased morbidity and mortality. CHD could be structural, as well as electrical disturbances in heart conduction. This entity is common, the incidence of structural heart disease is about 0.8-1.2% of life births worldwide [1]. Due to their altered heart structure, those patients are prone to developing intrinsic rhythm abnormalities [2] reaching an incidence of 6.3% before any surgery and increased acquired risk to develop arrythmia reaching up to 12% in the post-operative period. Similarly, arrythmias in the pediatric population with normal heart structure is also common. Those could be congenital or secondary to prematurity, immunologic or iatrogenic causes, reaching 5% of the emergency hospital admissions in this population with Wolff-Parkinson-White syndrome (WPW) being the most common [3].
The complex arrhythmogenic substrate in this mixed subtype (i.e., structural and electric heart condition) encompasses both arrhythmias commonly seen in the general population, and acquired arrhythmias associated with longstanding hypertrophy, fibrosis, and surgical scarring [4]. The clinical consequences of arrhythmias in those patients range from clinically occult arrhythmia to sudden death [4]. Thrombosis and thromboembolic events are additional complications [4]. Long-term anti-arrhythmic drug therapy has significant limitations in this group, and prospective studies of its efficacy are lacking[5]. Ablation strategies established in adults with normal hearts has been modified and adopted to treat the pediatric population especially those with congenital heart disease. The treatment is safe and effective with acceptable long-term results [5]. The use of radiofrequency energy for ablation of accessory pathways, atrioventricular node reentry tachycardia, and arrythmias has been showing marked success in pediatric and adult patients with congenital heart disease [6-8].
The decision to undergo catheter ablation in the pediatric population has been well established and follows specific indications depending on arrhythmia type, patient age and weight, and the presence or absence of congenital heart disease. Those indications have been outlined by the Pediatric and Congenital Electrophysiology Society (PACES) [9]. For instance, ablation is indicated in patients diagnosed with either atrioventricular reentrant tachycardia (AVRT) or atrioventricular nodal reentrant tachycardia (AVNRT), when supraventricular tachycardia (SVT) is frequently recurring or persistent, when there is inadequate response to medical therapy or intolerable side effects, or when there is family preference to avoid long-term therapy with antiarrhythmic drugs. Moreover, ablation is warranted for patients experiencing recurrent hemodynamic compromise necessitating electrical cardioversion. For instance, in patients with WPW weighing above 15 kgs, ablation is recommended for those having either syncopal episodes, high risk of cardiac arrest, or both. Asymptomatic patients weighing above 15 kgs and are at low risk for cardiac arrest may opt for ablation after understanding the risks entailed. While Premature Ventricular Contraction (PVC) patients with reduced Ejection fraction or a PVC burden of 20% or more are candidates for ablation based on patient/family consent. Ablation is also considered for patients with other kinds of arrhythmia substrates or in small patients weighing less than 15 kg, if antiarrhythmic medications are ineffective [9, 10].
Unfortunately, data on using catheter ablation for arrythmias in the Middle East region remains scarce. This study aimed to describe our experience in a tertiary care center with ablations of arrythmias in pediatric population who had structural, or electrical congenital heart diseases. Variables including procedural techniques applied, outcome in terms of acute success and recurrence, complications, and need for medications on discharge were explored.