What is Coronary Angiography?
The coronary angiogram is a commonly performed invasive procedure designed to assess the blood flow to the heart muscle through the coronary arteries. It is the gold standard test for accurate measurement of narrowing of the coronary vessels.
The technique involves the patient lying on an x-ray table and then being prepared by sterile cleansing of the access site (either the wrist or groin area) then the applications of a large sterile sheet across the patient to prevent any infection. Under local anesthesia a plastic introducing sheath (with 2mm x 20mm length is inserted into the artery and then plastic diagnostic tubes (catheters) are passed from the access site internally and positioned in the entrance of the coronary arteries. A special dedicated x-ray tube is then positioned above the patient and x-ray pictures are acquired whilst dye is injected internally through the patient’s coronary vessels making a discreet and clear image of the patient’s coronary artery dimensions. The x-ray tube can be adjusted to reduce the dose of radiation to the minimum amount and is able to be moved in all direction with precise control.
During the performance of an angiogram the patient has special plastic electrodes placed comfortably on the skin to monitor the heart beat during the performance of angiography. The catheter tubes are changed to different shapes and passed across a soft curved guide wire which prevents any damage to internal organs and is painlessly passed up to the entrance of the heart. Once the left and right coronary vessels have been fully assessed, then a final specially coiled plastic tube is passed painlessly into the center of the left heart pumping chamber and with injection of the dye, the pumping action can be accurately assessed and a warm sensation may be experienced at this point. The catheters are then gently extracted from the access site and discarded.
At the end of the angiographic study, the introducing sheath is then gently removed from the radial or femoral artery. A local pressure band is applied to the radial artery after sheath removal or if the femoral artery is used either a self dissolving collagen plug or simple stitch is placed in the wall of the femoral artery to minimize any bleeding and a pressure device maybe applied for up to 30 to 60 minutes if required. This test is usually performed as a day only investigation and patients will usually be allowed to return home on the same day with strict instructions to minimize their mobility for the next 24 hours.
PROCEDURAL RISKS: In order to obtain the gold standard diagnostic information regarding the arterial circulation of the heart, a coronary angiogram represents a very safe test with a very small risk of causing arterial damage or significant bleeding in rare circumstances.