[Cardiac insufficiency caused by iatrogenic arteriovenous fistula]

Two cases of iatrogenic arterio-venous fistula complicated by heart failure are described. A 50 year-old woman was admitted to the hospital with congestive heart failure and a questionable diagnosis of congestive cardiomyopathy. A continuous murmur heard over the lumbar spine close to a surgical scar from an intervention on the L4-L5 disc that the patient had undergone six months before, led to the diagnosis of an arterio-venous fistula. Angiography demonstrated a direct communication between the right iliac artery and the right iliac vein. After surgical closure of the fistula normal cardiac function was restored. The second patient (a sixty-year-old woman) had undergone surgical mitral valve replacement with a Hancock bioprosthesis 18 months before the current admission. In the post-operative period the percutaneous insertion of an intravenous line through the left jugular vein had been unsuccessfully attempted. She had mild heart failure which was ascribed to incompetence of the bioprosthetic valve. A continuous murmur in the left supraclavear area suggested the presence of an arterio-venous fistula. Angiography showed a direct communication between the supraclavear branch of the left subclavian artery and the left subclavian vein. The fistula was successfully closed. Both cases confirm the potential harmfulness for the vascular bed of certain surgical interventions and intravascular monitoring techniques. When heart failure of uncertain etiology appears in patients previously submitted to the one of the above mentioned procedures, a careful clinical examination can lead to a correct diagnosis of iatrogenic arterio-venous fistula, whose surgical correction is usually followed by the restoration of a normal cardiac function.