About Coronary Artery Disease (CAD)

Symptoms | Risk Factors | Diagnosis | Treatment

Coronary artery disease (CAD) occurs when the arteries (blood vessels) that supply blood to the heart muscle (the coronary arteries) become hardened and narrowed. The arteries harden and narrow due to build-up of plaque on their inner walls. The build-up of plaque is called atherosclerosis (ATH-er-o-skler-O-sis). As the plaque increases in size, the insides of the coronary arteries get narrower and less blood can flow through them. Eventually, blood flow to the heart muscle is reduced, and, because blood carries much-needed oxygen, the heart muscle is not able to receive the amount of oxygen it needs.

Reduced flow or cutoff of blood and oxygen to the heart muscle can lead to such problems as angina (chest pain) or heart attack (destruction of heart muscle). Over time, CAD can weaken the heart muscle and contribute to heart failure (heart unable to effectively pump blood) or arrhythmia (abnormal heart beat).

Symptoms

The most common symptoms of CAD are:

• Angina – chest pain or chest discomfort often mistaken for indigestion or heartburn or pain in the left shoulder, arms, neck, back or jaw
• Shortness of breath
• Palpitations – irregular heart beats or skipped beats
• A faster heartbeat
• Weakness or dizziness
• Nausea
• Sweating

In some people, the first sign of CAD is a heart attack. A heart attack occurs when plaque in a coronary artery breaks apart, causing a blood clot to form and block the artery.

Risk Factors

Several factors increase the risk of developing CAD. Some CAD risk factors can be modified, while others cannot.

Risk factors that cannot be modified:

• Age – as you get older, your risk increases
• Men – risk increases after age 45
• Women – risk increases after age 55
• Family history of early heart disease
• Heart disease diagnosed before age 55 in father or brother
• Heart disease diagnosed before age 65 in mother or sister

Risk factors that can be modified:

• Smoking
• High blood cholesterol
• High blood pressure
• Diabetes
• Obesity
• Lack of physical activity
• Stress and alcohol

Risk factors often occur in clusters and may relate to one another, such as obesity leading to diabetes and high blood pressure. When grouped together, certain risk factors put one at an even greater risk of CAD.

Diagnosis

Early diagnosis and treatment may stop the progression of CAD and help prevent a heart attack. When presenting with symptoms of CAD, a doctor will review a patient’s personal and family medical history, assess the patient’s risk factors, conduct a physical exam and order diagnostic tests. The following tests help a doctor evaluate the extent of CAD, its effect on the function of the heart and the best form of treatment for a particular patient:

• Blood Tests
• Electrocardiogram (EKG) – measures rate and regularity of heartbeat
• Echocardiogram – creates moving picture of heart showing size, shape and valve and chamber movement and function
• Stress test – monitors heart rate and blood pressure during physical activity
• Angiogram – views blood flow through the heart by injecting a special dye into the arteries that can be seen by a chest x-ray
• Cardiac catheterization – examines arteries for blockage with a thin, flexible tube passed through an artery in the groin or arm to reach the coronary arteries
• Nuclear heart scan – provides moving pictures of blood passing through the heart’s chambers and arteries by injecting a radioactive tracer into the bloodstream that is viewed by a special camera
• Electron beam computerized tomography – identifies and measures calcium build-up in and around the coronary arteries

Treatment

Treatment for CAD can include lifestyle changes, medications or specialty procedures (e.g., angioplasty, coronary artery bypass surgery). Lifestyle changes can include the following:

• Eat a healthy diet to prevent or reduce high blood pressure and high blood cholesterol and to maintain a healthy weight
• Quit smoking, if currently smoking
• Exercise, as directed by a doctor
• Lose weight, if overweight or obese
• Reduce stress

In addition to making lifestyle changes, medications may be needed to treat CAD. Some medications decrease the workload on the heart and relieve symptoms of CAD. Others decrease the chance of having a heart attack or dying suddenly and prevent or delay the need for a special procedure, such as angioplasty or bypass surgery. Several types of medicine are commonly used to treat CAD:

• Cholesterol-lowering medicines help to reduce cholesterol to a doctor-recommended level.
• Anticoagulants (AN-te-ko-AG-u-lant) help to prevent clots from forming in arteries and blocking blood flow.
• Aspirin, and other antiplatelet medicines, help to prevent clots from forming in arteries and blocking blood flow.
• ACE (angiotensin-converting enzyme) inhibitors help to lower blood pressure and reduce strain on the heart. They also may reduce the risk of a future heart attack and heart failure.
• Beta blockers slow the heart rate and lower blood pressure to decrease the workload on the heart. Beta blockers are used to relieve angina and may also reduce the risk of a future heart attack.
• Nitroglycerin widens the coronary arteries, increasing blood flow to the heart muscle and relieving chest pain.
• Long-acting nitrates are similar to nitroglycerin but are longer acting and can limit the occurrence of chest pain when used regularly over a long period.
• Dissolve the clots that can occur during a heart attack.