Coronary angiography is the procedure by which we visualize the coronary arteries. Coronary arteries are the arteries which supply pure blood to the heart muscles. There are two coronary arteries one right coronary artery and the left coronary artery. The left coronary artery further divides into two. One goes anteriorly while the other posteriorly so it can be said that there are 3 arteries. These arteries supply blood to the front, lateral, posterior and inferior part of the heart. To visualize these coronary arteries is called coronary angiography.
Angiography is done when the cardiologist is suspecting there is block in the coronary artery based on the patient symptoms, ECG or Stress test result. Hence, to confirm the block angiography is performed.
The Angiography report gives a lot of information about the coronary artery and its branches. It helps to identify
- Whether there is block in one or more arteries.
- If the bock is in the multiple branches of these arteries
- It also helps identify the extent of the blockage. To check if the block is significant block or insignificant block.
IF the block is more than 70% of the artery diameter it is called a significant block while if the block is less than 70% it is considered an insignificant block. If the block is significant, only then do we perform an angioplasty and bypass surgery. If block is less than 70% we do not do any intervention. Angiography helps measure the severity of the block if its 10%, 20% or more. It helps measure the extent of the block. i.e. How long is the block. It also helps identify if there is any abnormality of the artery, or any abnormal origin of the arteries.
Angiography is done on a patient in a conscious state, no general anaesthesia. Patient comes by 4 hour fasting.
The Procedure of Angiography:
The patient is given a local anesthesia, no general anesthesia, patient is awake and conscious. There is no cut. We just puncture the artery using a needle. The puncture is made either at the radial artery in the hand or femoral artery of the groin. First the local anesthesia is given to anesthetise the skin area and subcutaneous tissue. Then the puncture is made. Through the puncture a very thin wire or rubber tube is passed. This tube goes under the fluoroscopy, X-ray guidance. That tube is introduced from the puncture location to the point from where the coronary arteries originate. The tube is kept at the mouth of the coronary artery. Once here, a die is injected through the tube which allows identify the flow of blood in coronary artery and its branches. This is also called cine angiography. This entire procedure is called coronary angiography
If the procedure is done from the hand patient can go in 1hrs time. If the procedure is done from the groin the patient is discharged after 8hrs. of the procedure. The whole procedure takes about 10-15minutes.
The angiography is a safe procedure if performed by experienced doctors. It is a very safe procedure with negligible side-effects.
Precautions to take before angiography:
Before angiography the doctor does a general check-up of the patient to check if the patient is not in failure. As the patient has to lie-down on the table. We do certain blood test to check the haemoglobin of the patient, platelet count, Check creatinine to check kidney function, If the patient has kidney problems opinion of kidney specialist is taken. as the die might adversely affect the kidney. Certain diabetic tablets must be stopped 48hrs before the procedure. Viral marker test.