The authors reported a rare case of ectopic atrial tachycardia (EAT) with reversible myocardial dysfunction associated with enterovirus 71 (EV71) infection. A previously healthy 11-year-old boy presented with progressive heart failure. An initial ECG revealed a regular narrow QRS tachycardia with abnormal P wave morphology. Echocardiography showed severely impaired left ventricular function (LVEF 20%). Viral study (PCR) in stool was positive for EV71. Treatment with inotropic support, amiodarone, and carvedilol resulted in gradual restoration of sinus rhythm over 10 days. Cardiac function returned to normal within three months. EV71 can cause EAT along with other complications and should be considered in patients with persistent tachycardia and cardiac dysfunction. Recognizing this arrhythmia led to proper management to control ventricular rate, then termination of the tachycardia and gradual restoration of ventricular function to normal.

Keywords: Enterovirus 71; Ectopic atrial tachycardia; Myocardial dysfunction; Myocarditis; Heart failure

DOI: 10.35755/jmedassocthai.2023.02.13772

Received 16 August 2021 | Revised 14 November 2022 | Accepted 2 December 2022