Two young patients with complex congenital heart disease developed congestive cardiac failure and unilateral pulmonary oedema following palliative Blalock-Taussig pulmonary artery to systemic artery shunts. Following the failure of medical therapy these shunts were constricted by using braided silk ligature material, after which the heart failure and pulmonary oedema resolved.A transient degree of congestive cardiac failure is not uncommon after a systemic artery to pulmonary artery shunt performed as a palliative procedure for complex congenital heart disease. Young patients who have such heart disease for example, Fallot's anomaly (or tetralogy), pulmonary atresia, or transposition of the great arteries with pulmonary stenosis-frequently benefit from these shunts prior to final corrective surgery. Albers and Nadas (1967) have recently reported three patients with chronic unilateral pulmonary oedema and pleural effusion after systemic pulmonary artery shunts for cyanotic congenital heart disease. These three were controlled with medical therapy. The contralateral pulmonary artery was hypoplastic in two patients and in the third it was completely occluded.We report two patients who had palliative systemic-pulmonary artery shunts performed for cyanotic heart disease and who subsequently developed chronic congestive cardiac failure and unilateral pulmonary oedema despite intensive medical therapy. Because these patients were not controlled by medical therapy the subclavian artery used for the systemic-pulmonary artery shunt was constricted (banded), with good effect.CASE REPORTS CASE 1 Hospital No. P.P. A 31-year-old boy, 14 kg. in weight, was referred to the Hospital for Sick Children, Great Ormond Street, London, with a diagnosis of transposition of the great arteries. Subsequent investigations confirmed this diagnosis and in addition demonstrated a ventricular septal defect and infundibular and valvar pulmonary stenosis. The child's exercise tolerance was limited. He was cyanosed and had clubbing of the fingers. The chest radiograph showed an enlarged heart with oligaemic lung fields (Fig. I a).On 25 May 1967 a Blalock-Hanlon atrial septostomy (Blalock and Hanlon, 1950) and a right Blalock-Taussig systemic-pulmonary artery shunt were performed (Blalock and Taussig, 1945), the latter giving an 8 mm. shunt at the anastomosis. Within 36 hours signs of congestive cardiac failure and unilateral pulmonary oedema were present (Fig. lb). The child was immediately digitalized and given chlorothiazide and a low salt diet, but this regime had little effect. The heart failure continued to increase and one month after the operation he was in intractable congestive cardiac failure despite rigorous antifailure therapy, which then included frusemide (Fig. lc). The jugular venous pressure was higher than the angle of the mandible when measured in the routine way, and there was pitting oedema of the legs up to the knees and a pad of sacral oedema. As the medical therapy had failed it was assumed that the flow through the Blaloc...