The infant's EKG showed tachycardia to 180 and SVT.  Echo showed mildly depressed systolic function.  Viral studies for enterovirus, parvo, and echovirus were negative. She was started on amiodarone, after which cardiac function improved rapidly. She was discharged home after four days with the diagnosis of tachycardia-induced cardiomyopathy. Follow up echo 2 weeks later was normal.

Tachyarrythmias are uncommon cause of reversible cardiomyopathy. The precise pathophysiology is unclear, though likely involves remodeling of the myocardium in response to persistent tachycardia. This phenomenon may be seen with a variety of tachyarrhythmias, most commonly atrial fibrillation, atrial flutter, and SVT. There is no definite genetic predisposition or autosomal inheritance.

Patients typically present with symptoms of heart failure. Infants, as in this case, may develop signs of heart failure within days of onset of tachycardia. The prognosis is generally favorable with normalization of cardiac function once the arrhythmia is treated.

This case was submitted with supervision and input from:

Soni C. Chawla, M.D.
Associate Professor
Department of Radiological Sciences
David Geffen School of Medicine at UCLA
Olive View - UCLA Medical Center