Introduction:
Conjoined twins are a rare anomaly with severe complications. The incidence is about 1 in 50000 births and female predominant. We describe the conjoined twins with the conjugated heart receiving various examinations.

Methods:
The thoracopagus conjoined twins were born by a 27 year-old mother. The gestational age of the conjoined twin was 27 weeks and 2 days, and the birth body weight was 1770 gm. They were born via cesarean section (CS) due to the fetal distress. Electrocardiography (EKG), prenatal and postnatal echocardiography, and three-dimensional reconstruction computerized tomography (3DCT) were done for the further heart evaluation. Unfortunately, the patients expired 1 month later due to cardiopulmonary failure. Autopsy was done after patient died.

Result:
Heart anomaly of sharing one heart was noted prenatally. After birth, postnatal echocardiography showed a relative normal heart structure in twin A and double outlet of right ventricle, mitral valve atresia, hypoplastic left ventricle (LV) with underdeveloped ascending aorta in twin B. The connection of ventricles between twin A’s LV and twin B’s right ventricle were also noted. EKG showed shifting QRS axis and intermittent supraventricular tachycardia. The 3DCT confirmed the diagnosis and also revealed the abnormal venous returns.

Discussion:
Echocardiography can show the major structures of the conjoined twins’ heart. The 3DCT can reveal the more accurate and clear heart structure, especially the systemic and pulmonary venous returns. In conjoined twins with abnormal heart structure, the 3DCT is an exam of choice for anatomically evaluation even under the consideration of radiation burden in infancy.