A High-Level Athlete With Tachycardia-Induced Cardiomyopathy: A Can't Miss Diagnosis.

BACKGROUND: Pediatric athletes with tachycardia and ventricular dysfunction are often assumed to have dilated cardiomyopathy or myocarditis, but a broad differential should be maintained. CASE SUMMARY: An 18-year-old competitive athlete presents to the emergency room with tachycardia and chest pain. Electrocardiogram was thought to show high right-atrial tachycardia consistent with sinus tachycardia, and echocardiogram demonstrated diminished left ventricular systolic function without dilation. Viral myocarditis and cardiomyopathy genetic testing were negative. Further observation and workup demonstrated ectopic atrial tachycardia, which was treated, and the patient returned to sports. DISCUSSION: Tachycardia-induced cardiomyopathy is a rare, but reversible, cause of tachycardia and ventricular dysfunction. Exercise stress test can be useful in risk stratification. If returning to sport activity, an emergency action plan must be discussed with the patient and athletic training staff. TAKE-HOME MESSAGE: Tachycardia-induced cardiomyopathy can be a subtle diagnosis but should not be missed, as this disease can be reversible with appropriate treatment.