Coronary artery disease develops as a result of damage to the coronary arteries, the major blood vessels that supply the heart with blood, oxygen and nutrients. The most common causes of coronary artery disease are cholesterol deposits (plaque) in the arteries and inflammation.
A buildup of plaque narrows the coronary arteries and decreases blood flow to the heart. Over time, this can cause chest pain (angina), shortness of breath or other symptoms. A complete blockage of the coronary arteries can cause a heart attack.
Coronary artery disease usually develops over decades and it may go unnoticed until it causes a heart attack.
Symptoms
Symptoms of coronary artery disease may include:
- Chest pain (angina): Pressure or tightness in the chest and pain that is usually triggered by physical or emotional stress. In women, the pain may be fleeting or sharp and located in the abdomen, back or arm.
- Shortness of breath: Shortness of breath or extreme fatigue with exertion may be the result of insufficient blood pumped by the heart.
- Heart attack: Heart attack may be the result of completely blocked coronary artery with symptoms of chest pressure and pain in the shoulder or arm accompanied with sweating and shortness of breath.
Causes
Coronary artery disease is caused by damage or injury to the inner layer of a coronary artery. The damage may be caused by the following factors:
- Smoking
- High blood pressure
- High cholesterol
- Diabetes or insulin resistance
- Sedentary lifestyle
- Radiation therapy to the chest
Risk factors
Factors that increase the risk of coronary artery disease include:
- Increasing age
- Being male
- Family history
- Diabetes
- Obesity
- Physical inactivity
- Smoking (nicotine constricts the blood vessels and carbon monoxide can damage their inner lining making them susceptible to atherosclerosis)
- High blood pressure (uncontrolled high blood pressure hardens and thickens the arteries and narrows the blood flow channel)
- High blood cholesterol levels (this increases the risk of plaques and atherosclerosis)
- High stress (unrelieved stress can damage the arteries and worsen other risk factors)
Risk factors often occur in clusters and can build on one another. For example, obesity can lead to diabetes and high blood pressure. This combination increases the risk of coronary artery disease.
In some cases, coronary artery disease can develop without the classic risk factors. Alternative possible factors include:
- Sleep apnea: a disorder that causes one to repeatedly stop and start breathing while sleeping, which increases blood pressure and strain the cardiovascular system.
- C-reactive protein: This is a normal protein that increases in amount when there is swelling somewhere in the body. In this case, as the coronary artery narrows, the C-reactive protein in the blood increases.
- High triglycerides: A type of fat in the blood, which can increase the risk of coronary artery disease if present in high amount.
- Homocysteine: This is an amino acid used to make protein and to build and maintain tissue. High levels of homocysteine however, can increase the risk of coronary artery disease.
- Lipoprotein (a): Lipoprotein (a) forms when a low-density lipoprotein attaches to a specific protein. This can disrupt the body’s ability to dissolve blood clots, which may lead to coronary artery disease and heart attack.
Complications
Possible complications of coronary artery disease include:
- Chest pain (angina)
- Heart attack (complete blockage of the heart artery)
- Heart failure (chronic deprivation of oxygen and nutrients due to reduced blood flow or damage by a heart attack)
- Abnormal heart rhythm (arrhythmia)
Prevention
- Quit smoking
- Manage conditions such as high blood pressure, high cholesterol and diabetes
- Regular exercise
- Healthy diet (low-fat and low-salt diet)
- Healthy weight
- Reduce and manage stress
