Tachycardia-induced cardiomyopathy, often referred to as tachycardiamyopathy, is a condition where prolonged episodes of rapid heart rate (tachycardia) lead to weakened heart muscle function. This can result from various types of arrhythmias, most commonly atrial fibrillation or ventricular tachycardia. If the fast heart rate is controlled or corrected, the heart's function may improve over time, often reversing the cardiomyopathy. Prompt diagnosis and treatment are essential to prevent long-term damage to the heart.