Coronary Heart Disease

What Is Coronary Heart Disease?

Coronary heart disease, also called coronary artery disease, is the most common type of heart disease. It is usually caused by buildup of cholesterol and other substances in the arteries that supply blood to the heart.  A completely blockage of one of the arteries can cause a heart attack.  Coronary heart disease is a serious medical condition.  It is the leading cause of death in the US.  Adapting to a healthy lifestyle can reduce risks of developing this disease. 

How Is Coronary Heart Disease Diagnosed?

The following medical tests and procedures help doctors to diagnose coronary heart disease:

• History and physical examination:  Your doctor will ask you about your medical history and symptoms (e.g. chest pain and shortness of breath). You doctor will also perform a careful physical examination.
• Blood tests:  Blood samples will be taken to determine the possible damages in your heart. The doctor may learn from the results about the severity and prognosis of coronary heart disease.   
• Electrocardiogram (EKG or ECG): This test records the heart's rhythm, frequency of beats, and electrical conduction.  An electrocardiogram may reveal a previous heart attack or one in progress.  
• Exercise stress testing:  This test is helpful for the diagnosis for patients with symptoms occurring mostly during exercise. During the test, you will first walk slowly on a treadmill. Then the speed will be increased for a faster pace. The treadmill may also be tilted to produce the effect of going up a small hill. Your heart rate, heart beat rhythm, breathing, blood pressure and how tired you feel will be monitored during the test. 
• Echocardiography (Echo): This test is to measure the heart structure and function. This technique is noninvasive, safe, reliable, and reproducible.  
• Coronary angiography:  This medical procedure uses special dyes to image coronary arteries under x-ray. During this procedure, a thin flexible tubing will be inserted into an artery in your arm or groin (upper thigh), and threaded into the coronary arteries. And a special dye will be injected. Doctors will be able to determine the sites and severity of blood flow blockage.

What Are the Symptoms of Coronary Heart Disease?

Coronary heart disease often develops over decades. Most patients show no symptoms at early stages.  Many people experience chest discomfort, chest pain, and shortness of breath at later stages.  But some people even do not have these symptoms until heart attack arises.

What Are the Risk Factors for Coronary Heart Disease?

There are several factors that can increase the probability of developing coronary heart disease.  The major risk factors include:

• High blood cholesterol levels
• High blood pressure
• Past heart attack
• Family history of coronary heart disease
• Age
• Diabetes
• Overweight
• Stress
• Chronic kidney disease

Prevention and Treatment of Coronary Heart Disease

You cannot change some of the risk factors (e.g. age and family history). But taking control of other risk factors can help prevent or delay coronary heart disease.  The National Institutes of Health, the American Heart Association, and the American College of Cardiology recommend the following daily approaches, in addition to medical therapies:

• Monitor blood cholesterol: High blood cholesterol is a major risk factor for coronary heart disease. High blood cholesterol itself does not cause symptoms. Many people are unaware that their cholesterol level is too high. Lowering blood cholesterol levels reduces the chance of coronary heart disease. Everyone aged 20 years and older should measure blood cholesterol levels at least once every 5 years. A blood test called Lipid Panel, done after overnight fasting, tells you about your blood cholesterol levels. A healthy lifestyle helps to keep your cholesterol levels in the normal ranges (Table 1).

Table 1.  Blood Cholesterol Levels

• Monitor blood pressure: High blood pressure is a risk factor for coronary heart disease. Monitoring blood pressure at home can be helpful for controllinghigh blood pressure. Read High Blood Pressure to find out more about how lifestyle changes that can lower your blood pressure.
• Eat a better diet.  Consider the Dietary Approaches to Stop Hypertension (DASH) for an overall eating plan. The DASH diet plan emphasizes fruits, vegetables, and low fat dairy foods. It includes whole grains, poultry, fish, and nuts, but has reduced amounts of fats, red meats, sweets, and sugared beverages. Eating a DASH diet can help decrease high blood pressure and reduce risk of developing coronary heart disease.
• Eliminate trans fat intake and limit saturated fat intake:  Consumption of saturated fat and trans fat raises blood cholesterol levels, and increases the risk of coronary heart disease. Olive oil, peanut oil, and soybean oil are healthier alternatives. 
• Reduce sodium intake:  Another key to healthy eating is choosing foods lower in sodium. The current recommendation for a healthy individual is to consume less than 2.4 grams (2,400 milligrams) of sodium a day. Reducing sodium intake can help reduce risk of developing high blood pressure and coronary heart disease.
• Be physically active: Even moderate physical activity is beneficial for your overall health. If you have coronary heart disease, consult your doctor for the physical activities that best fit your condition.  
• Maintain a healthy weight: Overweight puts your heart with extra workload. If you are overweight, your dietitian can help you work toward your ideal weight.Even a small weight loss can reduce blood pressure and/or prevent high blood pressure in many overweight people (those with a Body Mass Index of 25 or greater).
• Stop smoking: Smoking can damage blood vessels, raise blood pressure, and increase the risk of developing coronary heart disease. If you smoke, your doctor may recommend a quit smoking program for you.
• Limit alcohol: If you drink, limit alcohol consumption to no more than two drinks per day for men and no more than one drink per day for women.

• Coronary heart disease is the most common type of heart disease (Table 2). About 16 million Americans (20 years or older) have coronary heart disease.  The American Heart Association estimates that 8 million more people in the US will have this disease in 2030.

Table 2.  Coronary Heart Disease in Different Ethnic Groups in the US

• In every minute, 4 people in the US are diagnosed with coronary heart disease, and 1 person dies from coronary heart disease.
• Coronary heart disease can lead to heart failure.
• The estimated cost for caring patients with coronary heart disease in the US is $190 billion in 2008. The cost is projected to increase to $380 billion in 2030.
• Healthy lifestyle factors are related to lower risks of coronary heart disease.