Truncus arteriosus communis is a rare CHD, accounting for only 1% of all congenital cardiac abnormalities. It has been associated with other malformations of the heart, mainly truncal valve (bicuspid/quadricuspid) and aortic arch abnormalities such as right, interrupted, and hypoplastic aortic arch. Cor tratriatrum sinistrum is another rare CHD, and it has been associated with other cardiac defects such as anomalous pulmonary venous drainage, ventricular septal defect, coarctation of the aorta, and tetralogy of Fallot. The combination of truncus arteriosus communis and cor tratriatrum sinistrum has not been reported so far. This case study describes the diagnosis of a unique case, including these two very rare cardiac defects and the successful surgical treatment thereafter.

Syncope has never been described as the presenting symptom of divided left atrium (cor triatriatum sinistrum). We have now encountered this mode of presentation in an otherwise asymptomatic patient. An upright tilt test elicited syncope prior to surgical correction, but failed to induce any symptom, even subsequent to infusion of isoproterenol, after surgery.

From January 1996 to April 2001, we treated eight patients with subdivided left atrium. Their ages at diagnosis ranged from newborn to 6.4 years. Prominent clinical symptoms were failure to thrive, respiratory symptoms, demand for oxygen, and congestive cardiac failure. Diagnosis was made by transthoracic echocardiography in all cases. Cardiac catheterization was necessary only in those patients who had associated cardiac anomalies, or suspected signs of pulmonary hypertension. In 7 patients, surgery was performed immediately after diagnosis, but one preterm infant died before operation due to neonatal sepsis and respiratory distress syndrome. In the postoperative period, one patient developed a severe capillary leak syndrome, and died due to irreversible congestive cardiac failure. The other 6 patients have all been followed up, with good results in the short- and intermediate-term at a mean of 34.3 ± 20.2 months. The infants were thriving, had a reduction in the frequency of infections of the respiratory tract, no significant arrhythmias, and showed early recovery from pulmonary hypertension and right ventricular hypertrophy.