Mitral atresia with premature closure of foramen ovale. A rare hemodynamic cause for failure of Blalock-Taussig anastomosis to relieve inadequate pulmonary blood flow.

The clinical, hemodynamic, and surgical findings encountered in the management of a hypoxic male infant with a rare and complex variety of cyanotic congenital heart disease associated with inadequate pulmonary blood flow are described. A poor clinical response to creation of a Blalock-Taussig anastomosis led to the discovery of mitral atresia complicated by premature closure of the foramen ovale and partially relieved by the presence of a levoatriocardinal vein. The subsequent creation of an atrial septal defect enhanced the function of the subclavian artery to pulmonary artery anastomosis and provided palliative relief of hypoxia. Some of the clinical and laboratory findings indicating the presence of additional lesions complicating the picture of a tetralogy of Fallot and requiring additional surgical considerations are discussed. The experience indicates that hemodynamic as well as surgical causes may explain the failure of a systemic artery to pulmonary artery anastomosis to function adequately and should be sought.