Coronary artery disease

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at May 23, 2016
StartDiseasesCoronary artery disease

Coronary artery disease is the most widespread form of heart disease and is the number one cause of death among both genders in the US. The heart moves roughly 2,000 gallons of blood through the body on a daily basis but it needs to have an adequate blood supply for it to work properly. Coronary artery disease restricts this blood supply and can cause heart attacks.

Contents

Definition & Facts

Most cases of coronary artery disease are caused by the accumulation of cholesterol-laden plaque in the blood vessels carrying oxygen-enriched blood to the heart. That buildup of plaque is also called atherosclerosis. It can take many years for the plaque to accumulate to the point at which it causes problems.

Over time, atherosclerosis narrows the arteries and hardens the arteries. The result of that narrowing is restricted blood flow to the heart. The lack of adequate blood flow can weaken the heart muscle and thus keep it from working well. If the flow of blood is completely obstructed by the plaque, this can cause a heart attack.

In some cases, plaque dubbed vulnerable plaque can rupture, and the body may try to repair the tear by forming a blood clot. That clot can break off and block the flow of blood in the artery, which is another way that coronary artery disease can cause a heart attack. Risk factors for coronary heart disease include diabetes and smoking

Symptoms & Complaints

During its earliest stages, atherosclerosis may not cause any symptoms. However, symptoms may start showing up as the arteries get progressively narrower. Narrow arteries are unable to carry enough blood to the heart, which means that it will not get enough oxygen. This can be especially problematic during periods of physical exertion.

The symptoms of restricted blood flow due to coronary artery disease include angina, which is pain in the middle or left side of the chest. This pain typically occurs as a result of physical exertion or emotional stress.

Women may also experience fleeting neck pain, back pain, or arm pain. In some cases, the chest pain may be accompanied by a sensation of tightening as if there was a weight resting on the individual's chest. In most cases, the pain will go away after the individual stops the stressful activity. Because the heart is unable to pump enough blood to provide sufficient oxygen to the body, the individual may also start suffering from shortness of breath and severe fatigue. Like angina, these symptoms will occur during periods of physical activity.

The most serious symptom of coronary artery disease is a heart attack. The main signs of a heart attack include an intense sensation of pressure on the chest, along with pain in the arm or shoulder pain. The symptoms of a heart attack may differ for women and may include pain in the neck or jaw pain.

Causes

The plaque that builds up in the arteries is laden with cholesterol from the diet. That cholesterol travels in the bloodstream in lipoproteins which are composites of fat and proteins. Low-density lipoproteins are the type of cholesterol that leads to plaque buildup. Low-density lipoproteins are sometimes called bad cholesterol, and the more low-density lipoproteins that an individual has in their blood, the greater their chance of developing coronary artery disease.

In addition to this, the plaque buildup can cause inflammation of the walls of the blood vessels and thus increase the risk of a heart attack. It can also make them sticky so that other substances in the blood adhere to them. The body may create new arteries that go around the clogged one but those arteries may not be able to provide the heart with an adequate supply of oxygen-rich blood.

Smoking is another major cause of coronary artery disease. Smoking causes blood platelets to clump together thus making clot formation more likely. It can also cause spasms in the coronary arteries that may reduce the flow of blood to the heart in much the same way that atherosclerosis does. In addition to all that, smoking can also lower the amount of high-density lipoproteins (good cholesterol).

Diagnosis & Tests

Along with asking questions about the patient's medical history and performing a physical examination, a doctor may also use the results of routine blood tests when diagnosing coronary artery disease. They may also order diagnostic tests like electrocardiograms. Electrocardiograms record the electrical signals that travel through the patient's heart and may show evidence of a heart attack that occurred in the past or one that is presently occurring.

An echocardiogram is another test used to diagnose coronary artery disease and involves the use of sound waves to provide images of the heart. An echocardiogram can help a doctor to determine whether all parts of the heart are working as they should. Some parts may be moving weakly because they were damaged during a heart attack. That damage may have resulted in them not getting enough oxygen.

In cases where the symptoms show up mostly during physical exertion, the doctor may ask the patient to walk on a treadmill or ride a stationary bike as an electrocardiogram is being performed. This type of test is called a cardiac stress test. As an alternative to physical exertion, a doctor may use medication to stimulate the heart for a stress test.

Treatment & Therapy

Lifestyle changes are the most common way to treat coronary artery disease. In some cases, drugs and medical procedures may also be used. The most effective lifestyle changes include quitting smoking along with opting for a healthier diet and regular exercise. Both of these lifestyle changes can help with weight loss, which can improve artery health.

Along with changes to an individual's lifestyle, doctors may also prescribe certain medications. Cholesterol-lowering medications decrease the amount of low-density lipoprotein; these medications include statins and niacin. Aspirin is another medication that is widely recommended for the treatment of coronary artery disease; it works by fighting the blood's tendency to clot and obstruct arteries.

Beta blockers are medications that slow down the heart's rate and that reduce blood pressure. The benefit of beta blockers is that they reduce the hearts' need for oxygen and can be helpful in preventing future heart attacks in patients who have already suffered one. Nitroglycerin works by dilating arteries while angiotensin-converting enzyme inhibitors lower blood pressure.

The two main surgical procedures for treating coronary artery disease are angioplasty and coronary artery bypass surgery. Angioplasty involves using thin tube into the artery and passing a balloon through it into the narrowed area where the balloon is inflated to compress the plaque buildup. Coronary artery bypass surgery involves using a graft to bypass the blocked arteries. The graft is taken from another part of the body.

Prevention & Prophylaxis

Many of the lifestyle changes used to treat coronary artery disease can also be used to prevent it. These include getting exercise along with eating a healthy diet to lose weight and reduce hypertension. There are also various prescription medications that can be used for lowering blood pressure; at-risk individuals may be able to prevent coronary artery disease by taking these medications as instructed.

Not smoking can also contribute to prevention efforts. In addition to the aforementioned methods, individuals who want to prevent the disease should consult with their doctor about the efficacy of taking low doses of aspirin each day.