A 12-year old boy from Armenia presented with chronic permanent ventricular tachycardia (150/min) and reduced left ventricular shortening fraction (< 30%). Tachycardia was present > 20 h/day on several 24-h Holter monitorings. Diagnosis of ventricular tachycardia could be established on surface ECG by identification of atrioventricular dissociation and a right bundle branch block pattern with a R/S ratio < 1 in lead V6. Antiarrhythmic therapy with mexiletine and sotalol alone or in combination did not influence the presence of the dysrhythmia. During electrophysiological study, the dysrhythmia could not be terminated by administration of adenosine, ventricular extrastimuli, overdrive stimulation or direct current cardioversion. Endocardial mapping identified a region on the left ventricular surface of the anterior upper interventricular septum as the origin of the dysrhythmia. At this location stimulation at a cycle length shorter than the tachycardia produced a QRS complex nearly identical to the tachycardia QRS complex. Local ventricular electrogram preceded the onset of the tachycardia QRS complex on surface ECG by 23 ms. Radiofrequency current application with 30 W for 30 s resulted in permanent termination of the tachycardia. No complications occurred. Six months after the intervention, the boy is still in normal sinus rhythm. Left ventricular function normalized.
Conclusion: Radiofrequency catheter ablation should be considered in young patients with drug-refractory chronic permanent ventricular tachycardia.