Mirror-image dextrocardia: why is the apex impulse not on the right?

This article presents the case of an 11-year-old girl with a history of Fortan surgery who presented to the authors' department with shortness of breath, orthopnea, and cyanosis. Electrocardiography (ECG) was indicative of mirror-image dextrocardia despite location of the apex impulse on the left. Echocardiography suggested mirror-image dextrocardia accompanied by levoversion, a large atrial septal defect and left ventricular atresia (functional single atrium and single ventricle), and right ventricular hypertrophy. ECG with corrected leads placement showed a sinus rhythm, biatrail enlargement, and right ventricular hypertrophy. Based on echocardiography and medical history, the case was rediagnosed as mirror-image dextrocardia with levoversion.