Learning Cardiology

Q. Most common cause of tachycardia induced cardiomyopathy is? A. Atrial flutter B. Atrial fibrillation C. Ventricular tachycardia D. Ventricular fibrillation Answer: B Explanation: Tachycardia induced cardiomyopathy (TIC) is defined as systolic and/or diastolic ventricular dysfunction resulting from a prolonged elevated heart rate which is reversible upon control of the arrhythmia or the heart rate. It is a rate dependent cardiomyopathy and those patients with higher tachycardia rates develop TIC earlier. Abnormal calcium handling, reduced cellular energy storing, and abnormal energy use have been proposed as the underlying mechanisms responsible for this syndrome. Pathologic changes start as early as 24-48 hours after onset of tachyarrhythmia in experimental models. Most common cause is supraventricular tachycardia and of them most common sustained tachycardia is atrial fibrillation.