Objective: Permanent junctional re-entrant tachycardia (PJRT) is a rare arrhythmia due to a concealed accessory pathway with decremental retrograde conduction properties. The arrhythmia, often incessant, may cause dilated cardiomyopathy, especially in infants. The objective was to analyze PJRT incidence, response to medication and catheter ablation results.

Methods: Thirteen PJRT patients under 15 years of age were identified for a retrospective study.

Results: The incidence of PJRT in Finland is approximately 1/100 000 children/year. PJRT was diagnosed prenatally or during neonatal period in 7 patients (54%). The tachycardia was incessant in three infants causing cardiomyopathy, which resolved in two after conversion to sinus rhythm. One infant died of neurological complications after treatment with an LV assisting device one week after presenting with arrhythmia and severe heart failure. The remaining 6 patients were diagnosed at median 12 years (range 2-14) and had normal LV function.

In five infants, 3-8 medications or combinations were needed before achieving arrhythmia control. At least 2 antiarrhythmic agents were needed in 9/13 patients. Flecainide, propafenone and sotalol were the most effective drugs.

Nine patients (median age 12.7 years, range 5.4-15.6) underwent catheter ablation. Accessory pathway location was right posteroseptal in 6, left lateral in 2, and left posterolateral in 1. The primary procedure was successful in 7/9 patients. A redo ablation was needed in one case after arrhythmia recurrence.

Conclusions: PJRT often manifests in infancy with incessant arrhythmia and tachycardia induced cardiomyopathy. The response to antiarrhythmic medication can be unsatisfactory. Older children benefit of catheter ablation.