Unusual course of outflow tract tachycardia and cardiac decompensation in childhood: a case report and review of the literature.

Outflow tract tachycardia (OT) is the most common form of idiopathic ventricular tachycardia (VT) in children. It is usually an incidental finding and presents only with mild symptoms. If affected patients have impaired left ventricular (LV) function, recovery usually progresses quickly after termination of the VT. To the best of the authors' knowledge, this is the first description of a 9-year-old female patient who presented with incessant right ventricular OT and LV dysfunction that was initially assumed to be tachycardiomyopathy and later diagnosed to be related to underlying laminopathy. The VT was successfully treated by radiofrequency ablation, and electroanatomical mapping demonstrated no signs of endocardial scarring. The VT had most likely been present for a prolonged period since the patient and initially presented with only mild symptoms of cardiac congestion despite severely impaired LV function. It seems probable that the laminopathy somehow influenced the unusual course of impaired LV function in this patient, who had either idiopathic VT combined with incidentally proven laminopathy or, less likely, outflow tract VT related to the laminopathy mimicking idiopathic VT.