Abstract: The characteristic of atypical atrial flutter episodes on electrocardiogram is different from the typical atrial flutter. Due to the poor diagnosis awareness about atypical atrial flutter, which is easily misdiagnosed as other arrhythmia, for example sinus arrhythmia, atrial fibrillation, and Ⅲ°atrioventricular block. Here we reported a case of atypical atrial flutter in child. In addition to the characteristics of typical atrial flutter, such as regular and more fixed atrial rhythm, fluctuated ventricular rate, faster atrial rate than the ventricular rate, the patient was found equipotential line, slow atrial rate, and uprighted F wave on the inferior wall leads and V1 lead of electrocardiogram, which were different from typical atrial flutter.

Key words: atrial flutter, tachycardia, ectopic atrial, atrioventricular block, electrocardiogram, child, atypical atrial flutter