CAD happens when the arteries that supply blood to heart muscle become hardened and narrowed. This is due to the buildup of cholesterol and other material, called plaque, on their inner walls. This buildup is called atherosclerosis. As it grows, less blood can flow through the arteries. As a result, the heart muscle can't get the blood or oxygen it needs. This can lead to chest pain (angina) or a heart attack. Most heart attacks happen when a blood clot suddenly cuts off the hearts' blood supply, causing permanent heart damage.
Over time, CAD can also weaken the heart muscle and contribute to heart failure and arrhythmias. Heart failure means the heart can't pump blood well to the rest of the body. Arrhythmias are changes in the normal beating rhythm of the heart.
The heart has 3 major coronary arteries.
- Two of these arteries arise from a common stem, called the left main coronary artery.
- The left main coronary artery supplies the left side of the heart.
- Its left anterior descending (LAD) branch supplies the front part of the heart.
- The left circumflex (LCX) branchsupplies the left lateral and back sideof the heart.
- Finally, the right coronary artery (RCA) is separate and supplies the right and the bottom parts of the heart.
Causes of CAD
Coronary artery disease is thought to begin with damage or injury to the inner layer of a coronary artery, sometimes as early as childhood. The damage may be caused by various factors, including:
Symptoms of CAD
If your coronary arteries become narrowed, they can't supply enough oxygenated blood to your heart — especially when it's beating hard, such as during physical activity. At first, the restricted blood flow may not cause any coronary artery disease symptoms. As the plaques continue to accumulate in your coronary arteries, however, you may develop coronary artery disease symptoms, including:
Coronary artery disease is thought to begin with damage or injury to the inner layer of a coronary artery, sometimes as early as childhood. The damage may be caused by various factors, including:
- Smoking
- High blood pressure
- High cholesterol
- Diabetes
- Radiation therapy to the chest, as used for certain types of cancer
Symptoms of CAD
If your coronary arteries become narrowed, they can't supply enough oxygenated blood to your heart — especially when it's beating hard, such as during physical activity. At first, the restricted blood flow may not cause any coronary artery disease symptoms. As the plaques continue to accumulate in your coronary arteries, however, you may develop coronary artery disease symptoms, including:
- Chest pain (angina). You may feel pressure or tightness in your chest, as if someone were standing on your chest. The pain, referred to as angina, is usually triggered by physical or emotional stress. It typically goes away within minutes after stopping the stressful activity. In some people, especially women, this pain may be fleeting or sharp and noticed in the abdomen, back or arm.
- Shortness of breath. If your heart can't pump enough blood to meet your body's needs, you may develop shortness of breath or extreme fatigue with exertion.
- Heart attack. If a coronary artery becomes completely blocked, you may have a heart attack. The classic signs and symptoms of a heart attack include crushing pressure in your chest and pain in your shoulder or arm, sometimes with shortness of breath and sweating. Women are somewhat more likely than men are to experience less typical signs and symptoms of a heart attack, including nausea and back or jaw pain. Sometimes a heart attack occurs without any apparent signs or symptoms.
Risk Factors of CAD
Some of the main risk factors that increase the risk for CAD are:
- Smoking
- Unhealthy cholesterol and lipid levels
- High blood pressure
- Diabetes
- Lack of exercise
- Obesity
Diagnostic Tests for CAD
The doctor will ask questions about your medical history, do a physical exam and order routine blood tests. He or she may suggest one or more diagnostic tests as well, including:
- Electrocardiogram (ECG). An electrocardiogram records electrical signals as they travel through your heart. An ECG can often reveal evidence of a previous heart attack or one that's in progress. In other cases, Holter monitoring may be recommended. With this type of ECG, you wear a portable monitor for 24 hours as you go about your normal activities. Certain abnormalities may indicate inadequate blood flow to your heart.
- Echocardiogram. An echocardiogram uses sound waves to produce images of your heart. During an echocardiogram, your doctor can determine whether all parts of the heart wall are contributing normally to your heart's pumping activity. Parts that move weakly may have been damaged during a heart attack or be receiving too little oxygen. This may indicate coronary artery disease or various other conditions.
- Stress test. If your signs and symptoms occur most often during exercise, your doctor may ask you to walk on a treadmill or ride a stationary bike during an ECG. This is known as an exercise stress test. In some cases, medication to stimulate your heart may be used instead of exercise.
Some stress tests are done using an echocardiogram. For example, your doctor may do an ultrasound before and after you exercise on a treadmill or bike. Or your doctor may use medication to stimulate your heart during an echocardiogram.
Another stress test known as a nuclear stress test helps measure blood flow to your heart muscle at rest and during stress. It's similar to a routine exercise stress test but with images in addition to an ECG. Trace amounts of radioactive material — such as thallium or a compound known as sestamibi (Cardiolite) — are injected into your bloodstream. Special cameras can detect areas in your heart that receive less blood flow. - Coronary catheterization. To view blood flow through your heart, your doctor may inject a special dye into your arteries (intravenously). This is known as an angiogram. The dye is injected into the arteries of the heart through a long, thin, flexible tube (catheter) that is threaded through an artery, usually in the leg, to the arteries in the heart. This procedure is called cardiac catheterization. The dye outlines narrow spots and blockages on the X-ray images. If you have a blockage that requires treatment, a balloon can be pushed through the catheter and inflated to improve the blood flow in your coronary arteries. A mesh tube (stent) may then be used to keep the dilated artery open.
- CT scan. Computerized tomography (CT) technologies, such as electron beam computerized tomography (EBCT) or a CT coronary angiogram, can help your doctor visualize your arteries. EBCT, also called an ultrafast CT scan, can detect calcium within fatty deposits that narrow coronary arteries. If a substantial amount of calcium is discovered, coronary artery disease may be likely. A CT coronary angiogram, in which you receive a contrast dye injected intravenously during a CT scan, also can generate images of your heart arteries.
- Magnetic resonance angiogram (MRA). This procedure uses MRI technology, often combined with an injected contrast dye, to check for areas of narrowing or blockages — although the details may not be as clear as those provided by coronary catheterization
How Is Coronary Artery Disease Treated?
- Relieve symptoms
- Reduce risk factors in an effort to slow, stop, or reverse the buildup of plaque
- Lower the risk of blood clots forming, which can cause a heart attack
- Widen or bypass clogged arteries
- Prevent complications of CAD
Lifestyle Changes
- Follow a heart healthy eating plan to prevent or reduce high blood pressure and high blood cholesterol and to maintain a healthy weight
- Increase your physical activity. Check with your doctor first to find out how much and what kinds of activity are safe for you.
- Lose weight, if you're overweight or obese.
- Quit smoking, if you smoke. Avoid exposure to secondhand smoke.
- Learn to cope with and reduce stress
Medicines
- Decrease the workload on your heart and relieve CAD symptoms
- Decrease your chance of having a heart attack or dying suddenly
- Lower your cholesterol and blood pressure
- Prevent blood clots
- Prevent or delay the need for a special procedure (for example, angioplasty or coronary artery bypass grafting
(CABG))
NEVER ABRUPTLY STOP TAKING ANY OF THESE DRUGS. Always talk to your doctor first. Stopping these drugs suddenly can make your angina worse or cause a heart attack
Medical Procedures
Angioplasty opens blocked or narrowed coronary arteries. During angioplasty, a thin tube with a balloon or other device on the end is threaded through a blood vessel to the narrowed or blocked coronary artery. Once in place, the balloon is inflated to push the plaque outward against the wall of the artery. This widens the artery and restores the flow of blood.
Angioplasty can improve blood flow to your heart, relieve chest pain, and possibly prevent a heart attack. Sometimes a small mesh tube called a stent is placed in the artery to keep it open after the procedure.
In CABG, arteries or veins from other areas in your body are used to bypass (that is, go around) your narrowed coronary arteries. CABG can improve blood flow to your heart, relieve chest pain, and possibly prevent a heart attack.
You and your doctor can discuss which treatment is right for you.
Complications of CAD
- Heart attack
- Heart failure
- Unstable angina
- Sudden death
Expectations (prognosis)
Everyone recovers differently. Some people can maintain a healthy life by changing their diet, stopping smoking, and taking medications exactly as the doctor prescribes. Others may need medical procedures such as angioplasty or surgery.
Although everyone is different, early detection of CAD generally results in a better outcome
Prevention of CAD
Tips for preventing CAD or lowering your risk of the disease:
- Avoid or reduce stress as best as you can.
- Don't smoke.
- Eat well-balanced meals that are low in fat and cholesterol and include several daily servings of fruits and vegetables.
- Get regular exercise. If your weight is considered normal, get at least 30 minutes of exercise every day. If you are overweight or obese, experts say you should get 60 - 90 minutes of exercise every day.
- Keep your blood pressure below 130/80 mmHg if you have diabetes or chronic kidney disease, and below 140/90 otherwise
- Keep your cholesterol and blood sugar under control.
- See your doctor regularly.
Moderate amounts of alcohol (one glass a day for women, two for men) may reduce your risk of cardiovascular problems. However, drinking larger amounts does more harm than good.
If you have one or more risk factors for coronary artery disease, talk to your doctor about possibly taking an aspirin a day to help prevent a heart attack or stroke. You may be prescribed low-dose aspirin therapy if the benefit is likely to outweigh the risk of gastrointestinal side effects.
Please note;
If you have any of the risk factors for CAD, contact your doctor to discuss prevention and possible treatment.
Immediately contact your doctor or go to the emergency room if you have:
- Angina
- Shortness of breath
- Symptoms of a heart attack
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