Our Center has a large experience of arrhythmias in children, even in neonates, particular in arrhythmias associated with congenital heart diseases. Our Group has also contributed substantially to the progress of treatment of tachyarrhythmias in children, with a major contribution to the scientific literature and to the current guidelines particularly for the treatment of asymptomatic children with ventricular preexcitation (Wolff-Parkinson-White Syndrome, WPW).
In our Center, pediatric arrhythmias are diagnosticated and treated, by implanting a pacemaker in cases of bradyarrhythmias (or slow arrhythmias), or by performing radiofrequency catheter ablation in cases of tachyarrhythmia (or fast arrhythmias), which can be definitively cured in most cases. Usually we have a conservative approach until the age of 5 years, and we perform catheter ablation in older children, preferable after 10 years. However, in children with tachyarrhythmias at risk of sudden death, cardiac arrest, syncope or heart failure, catheter ablation is mandatory and can be performed even in the first months of life or during the earlier childhood.
Supraventricular arrhythmias in children may occur either in presence of structural normal heart, or in presence of congenital heart disease.
The incidence of atrioventricular reciprocating arrhythmias associated to WPW is 85% of arrhythmias in fetal life and 82% of arrhythmias occurring during infancy. 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. In most cases, tachycardias will resolve spontaneously by the end of infancy, but late recurrency may occur. Catheter ablation is frequently performed to treat tachyarrhythmias involving a single or multiple accessory pathway in high symptomatic WPW children or in asymptomatic WPW children found at a high risk of sudden death.
Nodal reentrant 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 not 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 tachycardias are rare in childhood. Ventricular arrhythmias diagnosed in children with normal EKG, chest X-Ray, Echocardiograms and Electrophysiologic study or cardiac magnetic resonance (when performed) are generally benign, normally disappear during exercise and have a good long-term prognosis. Ventricular tachycardia occurring in children in association with hypertrophic cardiomiopathy, long QT syndrome (LQTS), Brugada syndrome (BrS), and arrhythmogenic right ventricular cardiomyopathy (ARVC) may have a worst prognosis, and must be studied with great care in the individual cases.
Right ventricular outflow tract (RVOT) tachycardia is occasionally discovered in teenagers and ARVC must be excluded. The EKG shows left bundle branch block (LBBB) 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.
Idiopathic left ventricular tachycardia arising from the posterior fascicle of the left bundle branch is rare and it responds to radiofrequency ablation. Catecholaminergic ventricular tachycardia is also induced by emotion, exercise, or isoprenaline and may degenerate in polymorphic ventricular tachycardia (torsade de pointes) frequently causing syncope if terminates spontaneously, or cardiac arrest and sudden death if degenerates into ventricular fibrillation. Torsade de point may also occur in children with long QT-syndrome, a familial disease characterized by prolonged and abnormal ventricular repolarization and risk of life-threatening 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 includes beta-blockade, antiarrhythmic drugs, left cardiac ganglionectomy and implantable cardiac defibrillator (ICD).
Complete atrioventricular block is the most important bradyarrhythmia in childhood. This arrhythmia may be congenital or may occur after cardiac surgery in congenital heart diseases. The symptom is usually a syncope (loss of consciousness) due to the bradycardia, and the therapy generally is a pacemaker implant.
The symptoms of arrhythmias in children depends essentially on the underlying cardiac conditions, as well as on the age at presentation. Usually neonates and infants with fast supraventricular or ventricular arrhythmias present with congestive heart failure due to tachycardiomyopathy. This symptom may occur in permanent junctional reciprocating tachycardia, incessant atrial ectopic tachycardia and ventricular tachycardia. Palpitations are the generally the first clinical manifestation of tachyarrhythmias in older children, and require clinical investigation, generally with ECG and Holter recording. Syncope (loss of consciousness) may be due either to bradyarrhythmias or to ventricular tachyarrhythmias, and always requires a complete diagnostic work-up. Sudden death is uncommon in children, but when it occurs, it is generally caused by ventricular arrhythmias degenerating into ventricular fibrillation. In case of sudden death in children, a familial diagnostic work-up is generally recommended.
Our Experience with Pediatric Arrhythmias
Our Center has a specific experience with pediatric arrhythmias, and younger patients will be assisted by dedicated Personnel throughout their clinical course, will be hospitalized with a parent and will have dedicated leisure areas.