Tachycardia-induced cardiomyopathy is an unusual cardiac disease that is life-threatening if tachycardia is not controlled. We report a 12-year-old boy who suffered from ectopic left atrial tachyarrhythmia that was refractory to medications and caused tachycardia-induced cardiomyopathy with severe heart failure. The patient required a left ventricular assist device (ABIOMED BVS5000 [ABIOMED Inc, Danvers, MA]) as a bridge to recovery. Tachycardia was finally controlled with flecainide while the patient was on left ventricular assist device support. The device was successfully explanted after 28 days of support. The temporary use of a left ventricular assist device was necessary to maintain a good hemodynamic status during the treatment of pharmacological refractory tachycardia, and it allowed a successful bridge to recovery.