CARDIAC CATHETERIZATION

procedure by which a flexible tube (catheter) is inserted into an artery or vein and passed along the course of that vessel into the heart. It is used for injecting drugs directly into the heart, for measuring the blood flow and the pressures in the heart and central blood vessels, in the diagnosis of congenital heart disease, in exploring narrowed passages and abnormal communications between heart chambers, and as a means of passing electrodes into the heart to restore or regulate the heartbeat. The procedure was originated by the German physician Werner Forssmann, who, in 1929, opened a vein in his own arm, inserted the tip of a catheter about 3.2 mm (0.125 inch) in diameter and 76 cm (2.5 feet) long, and passed it up his arm vein, along the intrathoracic veins, and on into the right atrium of his heart. More recent is the technique of left-heart catheterization, which involves passing a catheter up an artery, against the direction of blood flow; while somewhat more difficult and hazardous than venous passage, it is an extremely valuable diagnostic procedure. See also angiocardiography; diagnostic imaging.