Four children (age range 3 weeks to 15 years) with tachycardia induced cardiomyopathy due to permanent junctional reciprocating tachycardia (PJRT) underwent successful catheter ablation of the tachyarrhythmia circuit without any complications during or after the procedure. In all four patients, the left ventricular fractional shortening improved to normal within 2 weeks of the procedure. These results argue for a more aggressive approach to the therapy of PJRT when associated with tachycardiomyopathy at a young age.