RESUMEN
A mother presented with a fetus at 22±1 weeks of gestation with a sustained supraventricular tachycardia (SVT) at initially 186 beat per minute (bpm). The fetal M-mode echocardiography showed a 1/1 atrio ventricular ratio (with short atrioventricular (AV) interval and a long ventriculo-atrial (VA) interval, suggesting a Persistent junctional reciprocating tachycardia (PJRT) . Upon initial present no signs of heart failure or hydrops were noted and treament was initiated with amiodarone and digoxin . Fetus heart rate slowed .Postnatal electrocardiogram Confirmed the diagnosis of PJRT New born was put on amiodarone and proparonal). Sinus rhythm was rapidly achieved 9 days later .The patient doing well at 10 months of age with maintain of sinus rhythm. Conclusion: our case report illustrates a particular form of JRT diagnosed prenatal PJRT , characterized by a good clinical tolerance, its absence of evolution towards cardiomyopathy and its rapid and unusual response to antiarrhythmics.