Tachycardia, conventionally, but arbitrarily, defined as an atrial and/or ventricular rate of >100 beats per minute, is encountered commonly and can be physiological or pathological in origin. Various adverse consequences from tachycardia have been recognized, and an important one is the association between persistent tachycardia and cardiomyopathy. In this article, we provide an up-to-date review on the etiology of tachycardia, management strategies, and the prognosis of patients presenting with tachycardia and cardiomyopathy.