We present a rare case of two chambered heart (common atrium with common ventricle) in situsambiguous in a two month old male childview of dyspnea,fatigue and central cyanosis ,the patient was reffered to us with provisional diagnosis of congenital cyanotic heart disease. The baby had a body weight of 3.0 kg and an oxygen saturation of 80 % at room air. The auscultatory findings included a single first and second heart sound and soft grade II/VI ejection systolic murmur . Plain radiograph of chest in posterior-anterior view revealed the cardiac silhouette on the midline of thorax with base to apex axis to left suggestive of mesocardia.Trachea bifurcating into morphologically similar bronchi (bronchi are long and more vertical ?right sided), liver is transverse with absent fundic bubble shadow on left side.Chestradiogramradiograph goes in favour of right isomerism.Echocardiogram revealed inferior vena cava on left and aorta on right,a common atrium , single ventricle of left ventricular morphology ,common atrioventricular valve with moderate regurgitation,inferior vena cava opening into right side of common atrium,aorta on left and anterior,pulmonary atresia, left sided aortic arch with large PDA. Again these anomalies are commonly associated with right isomerism. Ultasonography of abdomen showed absence of spleen with midline liver and IVC and aorta on same side of spine favourig right isomerism.The patient was posted for a palliative Blalock-Taussig shunt surgery but died suddenly.
Key words: Cyanotic heart disease, heterotaxy, mesocardia, right isomerism, situs ambiguous.