Radionuclide findings in arteriovenous fistula between left pulmonary artery and vein.

Right-to-left extra cardiac shunts are usually congenital and are rarely due to trauma or complicating thoracic or vascular surgery. A case of a right-to-left cardiac shunt due to an arteriovenous fistula between the left pulmonary artery and the left pulmonary vein is reported. This may be the first report of this abnormality. The etiology is not clear. The case was investigated only by radionuclide procedures because the general condition of the patient was so poor that invasive procedures could not be undertaken.