1. Field of the Invention
This invention relates in general to medical equipment and procedures. In particular, the invention relates to a catheter assembly and a method of using the catheter assembly to perform coronary angiography and coronary angioplasty.
2. Description of Related Art
Coronary angiography and angioplasty are very common medical procedures. Angiography involves the insertion of a dye into certain arteries as a diagnostic aid. Angioplasty is a procedure to open a coronary artery which has become partially blocked by a stenotic lesion, an abnormal narrowing of an artery due to injury or disease. Both procedures involve the insertion of a catheter into the aorta, by way of the femoral artery, under local anesthesia. The tip of the catheter is inserted into the opening of the coronary artery. A dye can then be injected through the catheter into the coronary arteries for coronary angiography.
To perform coronary angioplasty, a dilating catheter is passed through the guiding catheter into the coronary artery. The tip of the dilating catheter is passed through the stenotic lesion in the coronary artery. A balloon on the tip of the dilating catheter is then inflated with a fluid. The balloon forces the blockage open and enlarges the lumen, or passage, through the artery.
A problem may develop during angiography and angioplasty. The guiding catheter, inserted into the lumen of the coronary artery, may occlude the flow of blood into the coronary artery. If the coronary artery is occluded and dye is injected through the catheter, life threatening cardiac arrhythmia, such as ventricular tachycardia, ventricular fibrillation, cardiac arrest, or myocardial infarction, may result.
One method of perfusing blood past the tip of the guiding catheter into the coronary artery is by providing a side hole in the catheter. However, if there is a side hole in the catheter, pressures at the tip of the catheter can no longer be monitored. Further, dye can no longer be injected through the catheter into the coronary artery, because most of the dye will pass through the side hole, rather than through the tip of the catheter.