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.