Coronary Artery Disease

What is Coronary Artery Disease?

Coronary artery disease (CAD) occurs when the coronary arteries, the blood vessels responsible for supplying the heart with blood, oxygen and nutrients, become occluded, diseased or damaged. Plaques (cholesterol deposits) on the arteries are the common cause of coronary artery disease. Plaque buildup narrows the coronary arteries, causing decreased blood flow and oxygenation to the heart. Eventually, this decreased blood flow could cause angina (chest pain), dyspnea (shortness of breath) and other coronary artery disease symptoms. When a complete blockage of the artery occurs, it would lead to a heart attack.

Coronary artery disease develops typically over an extended period of time, so it could go on unnoticed until it causes a heart attack. But there are many preventive measures and treatment regiments for CAD. Everything starts by having a healthier lifestyle.

Cardiovascular disease is the leading cause of death in the United States for both men and women, and is also a major concern worldwide. Centers for Disease Control and Prevention (CDC) estimated 61 million people in the US alone have heart conditions, and the World Health Organization (WHO) claims that 29 percent of deaths all over the world are related to the disorder. According to the American Heart Association, approximately 870,000 of the population died from heart disease last 2004 in the United States.

Symptoms of Coronary Artery Disease

If the coronary arteries are narrowed, they will not be able to supply enough oxygenated blood to the heart, especially during strenuous activity when the heart needs more oxygen. Initially, the restricted blood flow would not cause any symptoms, but as the plaque continues to develop in the arteries, symptoms would start to show, which include:

• Angina (Chest pain). This symptom is manifested as a tightness and heavy feeling in the chest. The episode is usually triggered by stress; either physical or emotional. It subsides after a few minutes with rest. The pain can be radiating through the abdomen, back or arm.
• Dyspnea (Shortness of breath). If the heart fails to pump an adequate amount of blood to meet the body’s requirements, the client may experience shortness of breath or extreme fatigue during exertion.
• Heart attack. A heart attack may occur when the coronary artery becomes completely occluded. The defining symptoms of a heart attack include a crushing pain in the chest radiating to the shoulder or the arm, sometimes accompanied with dyspnea and sweating. Women are more likely to experience other typical symptoms of heart attack like nausea and back or jaw pain. There are cases where a heart attack occurs without any warning signs or symptoms.

What Causes Coronary Artery Disease?

Coronary artery disease is thought to start initially with injury or damage to the inner layer (tunica intima) of the coronary artery, at times as early as childhood. The injury could be caused by different factors, including:

• Smoking
• Hypertension
• High cholesterol
• Diabetes
• Radiation therapy to the chest, which is used for specific types of cancer

When the inner wall of the artery gets damaged, plaques made of cholesterol and other cellular waste would accumulate at the injured area of the artery, a disease process termed as atherosclerosis. When these plaques break or rupture, platelets will try to stop the rupture by clumping at the injury site to try and fix the artery. This clump of platelets might cause arterial occlusion, which may lead to a heart attack.

Diagnosis of Coronary Artery Disease

Apart from obtaining medical history, physical assessment and order a full blood profile, other diagnostics may be needed as well, including:

• Electrocardiogram (ECG). This records the electric signals that travel through the heart. An ECG device could detect previous episode of a heart attack or a currently occurring case.
• Echocardiogram. This device uses sound waves to produce images of the heart. During the procedure, the physician could detect weak heart muscle damaged by a previous heart attack or is receiving a little amount of oxygen. This indicated coronary artery disease or other related conditions.
• Stress test. This is indicated for clients whose symptoms occur during stressful activities. The client would be asked to walk on a treadmill or to operate a stationary bike while on ECG. This will detect the amount of stress needed before experiencing any symptoms of the disease.
• Coronary catheterization. A procedure where an angiogram (an insertion of a dye into your arteries for visualization) is performed to assess if there are any occlusions to the coronary arteries.
• Computerized Tomography (CT) scan. CT scan can help in visualizing the arteries. A CT coronary angiogram could also be performed where a contrast dye is introduced intravenously during CT scan to generate images of the coronary arteries.
• Magnetic resonance angiogram (MRA). A magnetic resonance imaging (MRI) procedure combined with contrast dye injection to check for occlusions and narrowing of the coronary artery.

Treatment of Coronary Artery Disease

The treatment regiment for coronary artery disease usually includes lifestyle modifications and, if required, medications and various surgical procedures.

Lifestyle Changes

• Smoking cessation
• Healthy diet (low-sodium, low-fat)
• Regular exercise
• Weight modification
• Stress reduction

Drugs

• Cholesterol-modifying medications. Decreases low-density lipoprotein (LDL, or bad) cholesterol levels in blood, boosting the levels of high-density lipoproteins (HDL, or good) cholesterol.
• Aspirin. This medication dilutes the blood, thus preventing any clot formation. This is contraindicated on clients with bleeding disorders. It is important to ask the physician before taking this drug.
• Beta blockers. Slows down the activity of the heart and decreases blood pressure, thus decreasing the oxygen demand of the heart.
• Nitroglycerin tablets, sprays and patches. These medications dilate the arteries therefore increasing blood flow to the heart muscles.
• Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). These drugs reduce the client’s blood pressure thus helps in preventing coronary artery disease progression.
• Calcium channel blockers. Calcium channel blockers relax the vessels, increasing the blood flow to the heart. This would also cause to a decrease in blood pressure.

Surgical Procedures

• Angioplasty and stent placement (Percutaneous coronary revascularization). A stent would be left in the artery to keep the artery patent.
• Coronary artery-bypass surgery. A graft is created to bypass the blocked artery using a vessel from another part of the body.

How to Prevent Coronary Artery Disease

The same lifestyle modifications that are used to treat CADs can also be helpful in preventing the disease itself. These modifications include:

• Smoking cessation
• Controlling blood pressure
• Controlling diabetes
• Being physically fit
• Have a diet low in salt and fat
• Maintain an adequate body weight
• Stress reduction

References:

http://www.mayoclinic.com/health/coronary-artery-disease/DS00064/DSECTION=prevention

http://www.healthcommunities.com/heart-disease/heart-disease-overview.shtml