CORONARY ARTERY DISEASE

Coronary artery disease (CAD) is the narrowing of the arteries supply blood to the heart, called the coronary artery. This occurs because of a build up of fatty deposits along the inner wall of the artery. This process is known as atherosclerosis. CAD is a progressive disease, which increases the risk of heart attack and sudden death.

What is going on in the body?
In order for the heart to pump normally, the heart muscle needs a continuous supply of oxygen-enriched blood. This blood is delivered by the coronary arteries. Two main vessels branch out to supply blood to the entire muscle of the heart. The heart needs more oxygen during exercise and strenuous activity. It requires less when a person is resting. When the arteries become blocked, less blood can get through. The blockage can be small. In other cases, it completely obstructs blood flow. Blockage can occur in one or many coronary arteries. Small blockages may not always affect the heart's performance. The person may not have symptoms until the the heart demands a greater amount of oxygen-rich blood than the arteries can supply. This commonly occurs during exercise or other activity. The resulting pain is called stable angina. If a blockage is large, angina pain can occur with little or no activity, and is known as unstable angina . In this case, the flow of blood to the heart is so limited that the person cannot perform daily tasks without bringing on an angina attack. When the blood flow to an area of the heart is completely blocked, a heart attack occurs.

What are the signs and symptoms of the disease?
Symptoms of CAD vary widely. Also, a person's symptoms do not always indicate the severity the condition. The classic indicator of CAD is angina. This is characterized by chest pain that radiates to the neck, jaw or left arm. It also includes shortness of breath. The pain is often described as a crushing, burning or squeezing sensation. Some people may have no symptoms at all until they suffer a heart attack. Their physical exams may be completely normal, as well.

What are the causes and risks of the disease?
CAD affects people of all races. It can be caused by a combination of unhealthy lifestyle and genetics. Coronary risk factors that increase the risk of CAD include:

• high fat diet
• diet high in sodium
• overweight or obesity
• lack of exercise
• smoking

The genetic tendency for CAD makes a person's health habits particularly important. Avoiding lifestyle risks can prevent or delay the development of CAD.

What can be done to prevent the disease?
Deaths due to unhealthy lifestyle habits can be reduced by:

• following a healthy diet
• getting regular exercise
• not smoking

A healthy lifestyle may also help delay or prevent the development of CAD in people with a genetic tendency toward the disease. A person who is at high risk should strictly comply with treatments to lower cholesterol and blood pressure.

How is the disease diagnosed?
A first step in diagnosing the disease is to take the person's medical history. Important factors to consider include:

Also useful is an electrocardiogram, or ECG. This test may show indications of the effects of high blood pressure, areas of the heart deprived of blood, or scarring of the heart due to previous heart attack. An ECG may be normal between attacks of angina.

Another type of test, a stress test, is basically an ECG taken before, during and after exercise. It is designed to bring on an attack of angina and record the changes that occur in the heart on an ECG. Sometimes the person is injected with a substance called thallium during the stress test. Special pictures are then taken of the heart. The thallium scan can reveal areas of the heart that are damaged.

The most reliable test for diagnosing CAD, however, remains the coronary angiogram . In this procedure, a long and very thin hollow tube or catheter is inserted into an artery in the leg or arm. It is then advanced through the artery and into the coronary artery. A dye is injected into the tube. Pictures are taken as the dye is pumped into the coronary arteries. This illuminates blockages. Other techniques that are being used to help in the diagnosis CAD include stress echocardiograms and new generations of CT scans.

What are the long-term effects?
CAD is a progressive disease that can lead to heart attack and sudden death.

What are the risks to others?
The genetic tendency for the disease can be passed on from generation to generation. Otherwise there is no risk to others.

What are the treatments?
Treatment of CAD varies widely. It must be tailored for each person. The goal of treatment is to either reduce the amount of oxygen demanded by the heart or increase the oxygen supply. Two types of heart medications are commonly used for this purpose. The first reduces the work the heart has to do and therefore its oxygen needs. The other type relaxes the coronary arteries so more blood can get through to the heart. Medications that lower blood pressure and cholesterol are also very important. Other drugs such as aspirin are used to reduce the risk of blood clots.

In addition to medication, controlling risk factors such as poor diet and smoking is recommended for all people with CAD.

If the disease is severe, a person may need surgery or other procedures to alleviate the blockage in the arteries. One such procedure is a less invasive technique is called balloon angioplasty . A special balloon-tipped catheter is threaded into the coronary artery. It is similar to the catheter used to inject the dye when x-rays are taken of the arteries. Once the catheter is positioned at the point of the blockage, the balloon is then inflated to expand the narrowed area. The goal is to improve blood flow through the artery. Another option is heart bypass surgery to bypass the narrowed area. Blood flow is routed around the blockage using a blood vessel borrowed from another part of the body. This vessel is grafted to the coronary artery beyond the narrowed area providing an alternate route for blood flow to the heart. This procedure is commonly called coronary artery bypass graft, or CABG. Multiple vessels can be bypassed if more coronary artery is affected.

What are the side effects of the treatments?
All medications are associated side effects. These may include headache, dizziness and upset stomach. Blood thinning medications may increase the risk of bleeding and hemorrhage. Balloon angioplasty carries the risk that the vessel may become blocked again. Sometimes the angioplasty is not successful and CABG must be preformed at that time. The risk of CABG includes, bleeding, infection and death.

What happens after treatment?
People who have surgery or angioplasty are carefully watched to for bleeding, reocclusion of the artery and a return to the normal structure and function of the heart. Individuals are also helped to make needed lifestyle changes. Also, people will start special cardiac rehabilitation programs. It is important that individuals strictly adhere to their treatment plans.

How is the disease monitored?
People will need to visit the healthcare provider regularly to have their medictaions adjusted and their blood pressure and weight measured. Individuals should report the return or worsening of symptoms to the providrer. Periodic stress testing is required to make sure that there is proper blood flow to the heart.

Author: Eric Berlin, MD Source: Healthy Answers