Blockages prevent your heart from getting oxygen and important nutrients. This procedure is used to diagnose ischemic heart disease after chest pain, sudden cardiac arrest, or abnormal results from tests such as an electrocardiogram (EKG) of the heart or an exercise stress test. It is important to detect blockages because over time they can cause chest pain, especially with physical activity or stress, or a heart attack. If you are having a heart attack, coronary angiography can help your doctors plan your treatment.

Cardiologists, or doctors who specialize in the heart, will perform coronary angiography in a hospital or specialized laboratory. You will stay awake so you can follow your doctor’s instructions, but you will get medicine to relax you during the procedure. You will lie on your back on a movable table. Often, coronary angiography is done with a cardiac catheterization procedure. For this, your doctor will clean and numb an area on the arm, groin or upper thigh, or neck before making a small hole in a blood vessel. Your doctor will insert a catheter tube into your blood vessel. Your doctor will take x ray pictures to help place the catheter in your coronary artery. After the catheter is in place, your doctor will inject the contrast dye through the catheter to highlight blockages and will take x ray pictures of your heart. If blockages are detected, your doctor may use percutaneous coronary intervention, also known as coronary angioplasty, to improve blood flow to your heart.

After coronary angiography, your doctor will remove the catheter, possibly use a closure device to close the blood vessel, and close and bandage the opening on your arm, groin, or neck. You may develop a bruise and soreness where the catheter was inserted. You will stay in the hospital for a few hours or overnight. During this time, your heart rate and blood pressure will be monitored. Your movement will be limited to prevent bleeding from the hole where the catheter was inserted. You will need a ride home after the procedure because of the medicines or anesthesia you received.

Coronary angiography is a common procedure that rarely causes serious problems. Possible complications may include bleeding, allergic reactions to the contrast dye, infection, blood vessel damage, arrhythmias, blood clots that can trigger a heart attack or stroke, kidney damage, and fluid buildup around the heart. The risk of complications is higher in people who are older or who have certain conditions such as chronic kidney disease or diabetes. An imaging test called coronary computed tomography angiography, or coronary CTA, may be preferred over coronary angiography to detect blockages in the heart. Although coronary CTA still uses contrast dye, it does not require the invasive cardiac catheterization procedure that causes many of the complications of coronary angiography.

Coronary Circulation

You will recall that the heart is a remarkable pump composed largely of cardiac muscle cells that are incredibly active throughout life. Like all other cells, a cardiomyocyte requires a reliable supply of oxygen and nutrients, and a way to remove wastes, so it needs a dedicated, complex, and extensive coronary circulation. And because of the critical and nearly ceaseless activity of the heart throughout life, this need for a blood supply is even greater than for a typical cell. However, coronary circulation is not continuous; rather, it cycles, reaching a peak when the heart muscle is relaxed and nearly ceasing while it is contracting.

Coronary Arteries

Coronary arteries supply blood to the myocardium and other components of the heart. The first portion of the aorta after it arises from the left ventricle gives rise to the coronary arteries. There are three dilations in the wall of the aorta just superior to the aortic semilunar valve. Two of these, the left posterior aortic sinus and anterior aortic sinus, give rise to the left and right coronary arteries, respectively. The third sinus, the right posterior aortic sinus, typically does not give rise to a vessel. Coronary vessel branches that remain on the surface of the artery and follow the sulci are called epicardial coronary arteries.

The left coronary artery distributes blood to the left side of the heart, the left atrium and ventricle, and the interventricular septum. The circumflex artery arises from the left coronary artery and follows the coronary sulcus to the left. Eventually, it will fuse with the small branches of the right coronary artery. The larger anterior interventricular artery, also known as the left anterior descending artery (LAD), is the second major branch arising from the left coronary artery. It follows the anterior interventricular sulcus around the pulmonary trunk. Along the way it gives rise to numerous smaller branches that interconnect with the branches of the posterior interventricular artery, forming anastomoses. An anastomosis is an area where vessels unite to form interconnections that normally allow blood to circulate to a region even if there may be partial blockage in another branch. The anastomoses in the heart are very small. Therefore, this ability is somewhat restricted in the heart so a coronary artery blockage often results in death of the cells (myocardial infarction) supplied by the particular vessel.

The right coronary artery proceeds along the coronary sulcus and distributes blood to the right atrium, portions of both ventricles, and the heart conduction system. Normally, one or more marginal arteries arise from the right coronary artery inferior to the right atrium. The marginal arteries supply blood to the superficial portions of the right ventricle. On the posterior surface of the heart, the right coronary artery gives rise to the posterior interventricular artery, also known as the posterior descending artery. It runs along the posterior portion of the interventricular sulcus toward the apex of the heart, giving rise to branches that supply the interventricular septum and portions of both ventricles. Figure presents views of the coronary circulation from both the anterior and posterior views.

Your doctor may recommend coronary angiography if you have signs or symptoms of coronary heart disease (CHD). Signs and symptoms include:

• Angina. This is unexplained pain or pressure in your chest. You also may feel it in your shoulders, arms, neck, jaw, or back. The pain my even feel like indigestion. Angina may not only happen when you're active. Emotional stress also can trigger the pain associated with angina.

• Sudden cardiac arrest (SCA). This is a condition in which your heart suddenly and unexpectedly stops beating.

• Abnormal results from tests such as an EKG (electrocardiogram), exercise stress test, or other test.

Coronary angiography also might be done on an emergency basis, such as during a heart attack. If angiography shows blockages in your coronary arteries, your doctor may do a procedure called percutaneous (per-ku-TA-ne-us) coronary intervention, also known as angioplasty (AN-jee-oh-plas-tee). This procedure can open blocked heart arteries and prevent further heart damage.

Coronary angiography also can help your doctor plan treatment after you've had a heart attack, especially if you have major heart damage or if you're still having chest pain.

Before having coronary angiography, talk with your doctor about:

• How the test is done and how to prepare for it

• Any medicines you're taking, and whether you should stop taking them before the test

• Whether you have diseases or conditions that may require taking extra steps during or after the test to avoid complications. Examples of such conditions include diabetes and kidney disease.

Your doctor will tell you exactly which procedures will be done. For example, your doctor may recommend percutaneous coronary intervention, also known as coronary angioplasty, if the angiography shows a blocked artery.

You will have a chance to ask questions about the procedures. Also, you'll be asked to provide written informed consent to have the procedures.

It's not safe to drive after having cardiac catheterization, which is part of coronary angiography. You'll need to have someone drive you home after the procedure.

During coronary angiography, you're kept on your back and awake. This allows you to follow your doctor's instructions during the test. You'll be given medicine to help you relax. The medicine might make you sleepy.

Your doctor will numb the area on the arm, groin (upper thigh), or neck where the catheter will enter your blood vessel. Then, he or she will use a needle to make a small hole in the blood vessel. The catheter will be inserted in the hole. Next, your doctor will thread the catheter through the vessel and into the coronary arteries. Special x-ray movies are taken of the catheter as it's moved into the heart. The movies help your doctor see where to place the tip of the catheter.

Once the catheter is properly placed, your doctor will inject a special type of dye into the tube. The dye will flow through your coronary arteries, making them visible on an x ray. This x ray is called an angiogram. If the angiogram reveals blocked arteries, your doctor may use percutaneous (per-ku-TA-ne-us) coronary intervention (PCI), commonly known as coronary angioplasty to restore blood flow to your heart.

After your doctor completes the procedure(s), he or she will remove the catheter from your body. The opening left in the blood vessel will then be closed up and bandaged. A small sandbag or other type of weight might be placed on the bandage to apply pressure. This will help prevent major bleeding from the site.

After coronary angiography, you'll be moved to a special care area in the hospital. You'll be carefully watched for several hours or overnight. During this time, you'll need to limit your movement to avoid bleeding from the site where the catheter was inserted.

While you recover in the special care area, nurses will check your heart rate and blood pressure regularly. They'll also watch for any bleeding at the catheter insertion site. You may develop a small bruise on your arm, groin (upper thigh), or neck at the catheter insertion site. That area may feel sore or tender for about a week.

Let your doctor know if you develop problems such as:

• A constant or large amount of blood at the catheter insertion site that can't be stopped with a small bandage

• Unusual pain, swelling, redness, or other signs of infection at or near the catheter insertion site

Your doctor will tell you whether you should avoid certain activities, such as heavy lifting, for a short time after the test.

Coronary angiography is a common medical test. It rarely causes serious problems. However, complications can include:

• Bleeding, infection, and pain at the catheter insertion site.
• Damage to blood vessels. Rarely, the catheter may scrape or poke a hole in a blood vessel as it's threaded to the heart.
• An allergic reaction to the dye that’s used during the test.

Other, less common complications include:

• Arrhythmias (irregular heartbeats). These irregular heartbeats often go away on their own. However, your doctor may recommend treatment if they persist.
• Kidney damage caused by the dye that’s used during the test.
• Blood clots that can trigger a stroke, heart attack, or other serious problems.
• Low blood pressure.
• A buildup of blood or fluid in the sac that surrounds the heart. This fluid can prevent the heart from beating properly.

As with any procedure involving the heart, complications can sometimes be fatal. However, this is rare with coronary angiography.

The risk of complications is higher in people who are older and in those who have certain diseases or conditions (such as chronic kidney disease and diabetes).