heart and blood vessel disorders
Pulmonary Artery Catheterization
How pulmonary artery catheterization is done
As in right Cardiac Catheterization and Coronary Angiography , a catheter with a balloon at its tip is inserted into a vein, usually in the neck, under the collarbone, in the groin, or in an arm, and is threaded toward the heart. The tip of the catheter passes through the superior vena cava or inferior vena cava (the large veins that return blood to the heart from the upper and lower parts of the body) and through the right atrium and right ventricle to the pulmonary artery. The balloon at the catheter's tip is lodged in the pulmonary artery. A chest x-ray is taken or fluoroscopy (a continuous x-ray procedure) may be used to make sure the tip is placed correctly. The balloon is inflated to temporarily block the pulmonary artery, so that pressure in the capillaries of the lungs (pulmonary capillary wedge pressure) can be measured. This measurement is an indirect way to determine pressure in the left atrium. Blood samples can be taken through the catheter, so that the oxygen and carbon dioxide levels in the blood can be measured. 