Predictors of Refractory Tachycardia in Preschool Children

Aim: To analyze the results of antiarrhythmic therapy (ATT) in preschool children with arrhythmias.

Methods and materials: 100 patients with arrhythmias got prolonged AAT. They were 42 pts with WPW syndrome, 38 children with atrial tachycardias, 11 with ventricular tachycardias, 9 with extrasystole. Children were till one year old – 41 pts, from 1 till 3 - 23, from 3 till 7 - 36. Reasons for drug therapy were heart attacks prevention, sinus rhythm recovery or heart rate control at the level of normosystole with permanent and incessant tachycadias; depression and decrease of ectopic activity of arrhythmia focus. The therapy duration varied from 10 days till 12 months. The most children were prescribed monotherapy. When it was ineffective, in 19 patients, they got combined treatment. With the aim of assessment of Holter and EchoCG during prolonged AAT their comparison analysis was carried out initially, at 5-8 day after efficiency criteria appearance, and also in 6 months after therapy withdrawal.

Results: Prolonged AAT was effective in 38% of pts and ineffective in 62% of children. The assessment of results of antiarrhythmic therapy using discriminative analysis allows defining factors influencing on its effectiveness, they were age and presence of echocardiographic signs of thachyinduced cardiomyopathy (TICMP). Children under one year old with WPW syndrome, paroxysmal tachycardia and without TICMP signs have greater chance of effective AAT.

Conclusion: Patients of early age with tachyarrhythmias which aren’t accompanied by heart structural changes expect effective result of drug therapy. Patients after one year old with echocardiographic signs of tachyinduced cardiomyopathy should expect ineffective AAT result and perform RFA.