This is a procedure involving the introduction of a catheter into the right side or the left side of the heart to study the pressures in the central vein, across the valves of the arteries and the chambers of the heart. The volumes in the cardiac chamber during the cardiac cycle and the patency of the coronary artery are also measured by observing the flow pattern of radiographic dye injected through the catheter. Right heart catheterization measures the right atrial, right ventricular, pulmonary artery and pulmonlary capillary wedge pressures, oxygen saturation, and cardiac output. The catheter is inserted through the femoral vein or subclavian vein. Left heart catheterization measures the aortic and mitral valve stenosis and regurgitations, global and regional left ventricular functions and coronary ateriography.The catheter is inserted through the femoral artery or the brachial artery. Alternative courses of action include: ultrasound, thallium scan, which can give an accurate idea of ventricular function, but neither can demonstrate the degree and location of obstruction of the coronary artery. Material effects, risks and side effects include: allergy to the radiography dye, bleeding, pneumothorax, arrhythmias, air emboli, pulmonary emboli, pulmonary artery rupture and infarction, cerebrovascular accident, myocardial infarction, perforation of the myocardium, infections, sepsis, vasovagal reactions. Local vascular complications at the site of puncture: arterial thrombosis, arterial laceration or dissection, pseudoaneurysm, hematoma, a-v fistula. mean pressure systolic pressure end diastolic pressure right atrium 0 - 8 - - right ventricle - 15 - 30 0 - 8 pulmonary artery 9 -16 15 - 30 3 - 12 pulmonary capillary wedge and left atrium 1 - 10 - - left ventricle - 100 - 140 3 -12 systemic arteries 70 - 105 100 - 140 60 - 90