Our extensive experience among children with tachyarrhythmias has substantially contributed to the scientific literature progress in order to revisit current guidelines particulary in asymptomatic children with ventricular preexcitation.

In our center pediatric arrhythmias are diagnosticated treated and could be definitively ablated by radiofrequency. Usually we have a conservative approach until 5 years of age and perform catheter ablation in older children, preferable after 10 years. However, in children who have tachyarrhythmias associated with a risk of sudden death, cardiac arrest, syncope or heart failure catheter ablation is  mandatory and can be performed evn in the first months of life or during the earlier childhood.

Supraventricular arrhythmias

Catheter ablation is frequently performed to treat definitively tachyarrhythmias involving a single or multiple accessory pathway in high symptomatic children or in asymptomatic WPW children found  at a high risk of sudden death. The incidence of   atrioventricular  reciprocating is 85 % of the arrhythmias in fetal life and 82% of the arrhythmias occurring during infancy. In most cases tachycardia will resolve spontaneously by the end of the infancy but late recurrency may occur. The incidence decrease to 65% in the 1-5 age group, 56% in the 6-10 age group and 68% in children over 10 years old age. Atrioventricular nodal re-entrant   tachycardia is uncommon during infancy with an incidence of 23% in the 1-5 age group, 34% in the 6-10 age group, and 20% in those over 10 years of age. Most cases do nort resolve spontaneously requiring catheter ablation. Less common arrhythmias include atrial flutter and atrial ectopic tachycardia with an incidence about 10-15% during childhood and most of them resolve spontaneously. If persistent radiofrequency ablation is required to definitively cure them.

Ventricular arrhythmias

Ventricular tachycardia is rare in  childhood and may be benign or malignant. The benign form normally is diagnosticated in children who have normal EKG, chest X-Ray,  Ecocardiography and a normal EP study (when performed). Ventricular tachycardia disappears during exercise and is usually refractory to drugs with a good long-term prognosis. Ventricular tachycardia although uncommon, occurs in children in association with hypertrophic cardiomiopathy, long QT syndrome and Brugada syndrome. Right ventricular outflow tachycardia is occasionally discovered in teenagers and is different from arrhythmogenic right ventricular dysplasia or cardiomiopathy. The ECG shows left bundle branch block with a vertical or right axis. This form of ventricular tachycardia is commonly induced by exercise or emotions and can be reproducibly induced by isoprenalin and is responsive to RF catheter ablation. Idipathic left ventricular tachycardia is rare arising from the posterior fascicle of the left bundle branch and is responsive to radofrequency ablation. Catecholaminergic ventricular tachycardia is also induced by emotion, exercise, or isoprenaline and may degenerate in atypical ventricular tachycardia (torsade de pointes) frequently causing syncope. Ventricular tachycardia may also occur in children with long QT-syndrome wich is a familial disease carachterized by prolonged and abnormal ventricular repolarization and by the risk of  life-treatening ventricular arrhythmias, cardiac arrest or sudden death. The mortality among untreated symptomatic children is up to 70% within 15 years after the first syncopal episode. Treatment approach includes  beta-blockade, antiarrhythmic drugs and automatic implantable cardiac defibrillator (AICD).  

Symptoms

The symptomatology of arrhythmias in children depends essentially on the underlying rhythm disturbance as well as on the age at presentation. Usually neonates and infants with arrhythmias present with congestive hearth failure due to tachycardiomyopathies. This sequence occurs following permanent junctional reciprocating tachycardia, incessant atrial ectopic tachycardia and ventricular tachycardia. Palpitations and/or syncope are the first clinical manifestation in older children. Complete hearth block is the most important bradyarrhythmia  in childhood. This arrhythmia may be either of congenital etiology or may occur after cardiac surgery. Sudden death is uncommon in children with arrhythmias but when it occurs,  is frequently caused by ventricular arrhythmias.