Divided right atrium associated with extensive coronary vein abnormalities

This report describes a case of a divided right atrium associated with coronary vein abnormalities. An 18-year-old woman who had a past history of surgery for repair of a divided right atrium and atrial septal defect developed exertional dyspnea 8 years after the surgery. Selective coronary angiography showed a dilated right coronary artery with a fistulous communication to the right atrium, tortuous coronary veins draining directly into the cardiac chambers, and the absence of the coronary sinus. Embryologically, regression failure of the right venous valve is hypothesized to have created both the divided right atrium and extensive coronary vein abnormalities.