Tachycardia-induced cardiomyopathy: mechanisms of heart failure and clinical implications.

The prognosis of dilated cardiomyopathy is generally poor. The cause of ventricular dysfunction often cannot be identified. In most cases, the clinical history of cardiomyopathy is irreversible but, in some cases, potentially curable causes may be identified. The development of cardiomyopathy may be correlated to atrial or to ventricular arrhythmias. In this scenario, atrial fibrillation is the most frequent cause of ventricular dysfunction, even if it may also be secondary to heart failure. The diagnosis of tachycardia-induced cardiomyopathy can be made only after the improvement of the left ventricular function once the cardiac frequency has slowed down.