Reversible cardiomyopathy after radiofrequency ablation of lateral free-wall pathway-mediated incessant supraventricular tachycardia.

Incessant supraventricular tachycardia leading to reversible cardiomyopathy has been reported. Cardiomyopathy usually only develops after prolonged episodes of tachycardia at a significant heart rate. Left ventricular free-wall pathways rarely cause fast and incessant tachycardia. Therefore cardiomyopathy has not been reported with left ventricular free-wall pathway-mediated supraventricular tachycardia. We report on two cases of left ventricular free-wall-mediated supraventricular tachycardia leading to reversible cardiomyopathy after radiofrequency ablation. These cases illustrate the difficulty in diagnosing tachycardia-mediated cardiomyopathy, as the tachycardia may be clinically silent. In addition, they emphasize the importance of making this diagnosis, as the cardiomyopathy is reversible.