Understanding the Causes and Symptoms of Coronary Artery Disease
Ischemic heart disease occurs when the vessels that carry blood to the heart are blocked, and the heart muscle doesn’t get enough oxygen. Our hearts beat about 100,000 times each day and circulate around six liters of blood throughout our bodies each minute. To maintain this workload, our heart muscle requires a constant supply of blood and oxygen.
With an inadequate supply of oxygen, the affected heart muscle does not function normally, and the muscle is said to be ischemic. This is often experienced as chest pain. If the lack of oxygen is very severe, the heart muscle will begin to die. This is known as a myocardial infarction or a heart attack.
Causes of Ischemic Heart Disease
Atherosclerosis is a disease process affecting our arteries. It is the buildup of fat and cholesterol within the wall of an artery. The region of buildup is known as plaque. These plaques can gradually grow, ultimately blocking the flow of blood. Often a blood clot may form on the plaque causing it to suddenly block the artery, which can lead to an acute myocardial infarction.
Some ethnic groups are at a higher risk for ischemic heart disease, often due to disparities in access to affordable health care. In the African American community, where hypertensive disease is more common, there is a greater risk of ischemic heart disease. Similarly, there is an increased incidence in the Latino/Hispanic community, which tends to have a higher rate of diabetes, and certain East Indian populations, with particularly elevated cholesterol levels. (You can check your risks with our online health assessment.)
Preventing Ischemic Heart Disease
There are steps you can take to reduce your risk, such as maintaining a healthy diet low in fat, salt and simple sugars. A healthy diet is based on fruits, vegetables and whole grains. Other important lifestyle changes must include: regular exercise (at least 30 minutes, five times a week), quitting smoking, healthy weight management, and maintaining optimal cholesterol and blood pressure values. (This article on how to make resolutions succeed has practical suggestions to help you prepare for changes.)
When to See a Doctor
Common symptoms of ischemic heart disease include:
Pain or discomfort in the chest, jaw, arm or shoulder
Shortness of breath
Nausea and/or vomiting
Indigestion or gas-like pain
Dizziness or fainting
Women often describe and experience their symptoms differently than men so it’s important for clinicians to listen carefully and for women to be aware of the unique signs of a heart attack in women. Avoid denial. Take any suggestive symptoms seriously. If you are uncertain, seek medical attention immediately and do not hesitate to call 911.
Treatment for Ischemic Heart Disease
Should you have symptoms, your doctor will obtain a complete history, conduct a physical examination and perform an electrocardiogram (EKG), which is a noninvasive test that measures the electrical activity of your heart.
If your doctor finds evidence of ischemic heart disease, you will be referred to a cardiologist. The subsequent evaluation will likely involve a form of stress testing to noninvasively reveal evidence of ischemic heart disease. For high risk individuals or those with noninvasive evidence of ischemic heart disease, coronary angiography may be required. A coronary angiogram is an invasive procedure involving the insertion of a catheter or tube into an artery. It is advanced to the heart and dye is injected into the coronary arteries, allowing them to be visualized with X-ray evaluation.
Coronary atherosclerotic plaques are treated three ways:
Percutaneous coronary intervention involves angioplasty. This is performed like the coronary angiogram but at the end of the catheter is a small balloon. The balloon is deflated and a metal coil, or stent, is collapsed on top of the balloon. The balloon is advanced down the coronary artery and positioned at the site of the coronary plaque. The balloon is inflated, expanding the stent. The balloon is then deflated and the catheter is removed leaving the expanded stent in place. By relieving the blockage, the stent reestablishes blood flow through the artery. Surgical intervention, or coronary bypass, involves removing vessels, typically from the legs, or diverting arteries and using them to bypass blocked coronary arteries.