Treatment of arrhythmias by radiofrequency ablation.

The Jtournal of the British Paediatric Association Annotations Treatment of arrhythmias by radiofrequency ablation Cardiac arrhythmias in children are often caused by the presence of an anatomical connection between the atria and ventricles known as accessory pathways. When these pathways conduct impulses antegradely, they manifest themselves as Wolff-Parkinson-White syndrome on the surface electrocardiogram (ECG) but some only conduct retrogradely, in which case the ECG is normal when in sinus rhythm, although they still carry the potential for a re-entrant circuit manifesting in tachycardia. Accessory pathways occur in around 1-5 per thousand population and two thirds are symptomatic. Apart from accessory pathways, there are other forms of re-entrant tachycardias involving the atrioventricular node or the ventricles. In addition, some patients have tachyarrhythmias as a result of an irritable focus either in the atria or ventricles. These mechanisms, once identified and located, can be removed and the risk of tachycardia abolished. Presentation can be in fetal life, at birth, later on in childhood, or adulthood. Some lose the potential to develop arrhythmias as they grow older but may recur later. Less than 3% of arrhythmias in children are fatal or accompanied by major com- plications, unless associated with congenital or structural heart defects or after cardiac surgery. They are, however, disturbing to the patients and their unpredictability under- mines patient and family confidence. Individual attacks may respond to vagal manoeuvres but sustained or recur- rent tachycardias require treatment with prophylactic antiarrhythmic drugs with the occasional need for intra- venous treatment or direct current (DC) cardioversion for an acute episode. Patents and children find antiarrhythmic drug treatment undesirable and procedures to cure arrhythmias, especially in children are, therefore, very welcome.