Coronary heart disease (CHD), or coronary artery disease, develops when the coronary arteries become too narrow. The coronary arteries are the blood vessels that supply oxygen and blood to the heart.
CHD tends to develop when cholesterol builds up on the artery walls, creating plaques. These plaques cause the arteries to narrow, reducing blood flow to the heart. A clot can sometimes obstruct the blood flow, causing serious health problems.
Coronary arteries form the network of blood vessels on the surface of the heart that feed it oxygen. If these arteries narrow, the heart may not receive enough oxygen rich blood, especially during physical activity.
CHD develops as a result of injury or damage to the inner layer of a coronary artery. This damage causes fatty deposits of plaque to build up at the injury site.
These deposits consist of cholesterol and other waste products from cells. This buildup is called atherosclerosis.
If pieces of plaque break off or rupture, platelets will cluster in the area in an attempt to repair the blood vessel. This cluster can block the artery and reduce or block blood flow, which may lead to a heart attack.
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Angina may cause the following feelings across the chest:
Angina might also cause the following symptoms:
CHD can also lead to shortness of breath. If the heart and other organs do not receive enough oxygen, any form of exertion can become very tiring, which may cause a person to pant for air.
Heart attack occurs when the heart muscle does not have enough blood or oxygen, such as when a blood clot develops from plaque in one of the coronary arteries.
The formation of a blood clot is called coronary thrombosis. This clot, if it is big enough, can stop the supply of blood to the heart.
Symptoms of a heart attack include:
- chest discomfort
- mild or crushing chest pain
- shortness of breath
- a gray pallor in the face
- general discomfort
- nausea and vomiting
- clammy skin
The first symptom is usually chest pain that spreads to the neck, jaw, ears, arms, and wrists, and possibly to the shoulder blades, back, or abdomen.
Changing position, resting, or lying down is unlikely to bring relief. The pain is often constant but may come and go. It can last from a few minutes to several hours.
A heart attack is a medical emergency that can result in death or permanent heart damage. If a person is showing symptoms of a heart attack, it is vital to call the emergency services immediately.
There is no cure for CHD. However, there are ways that a person can manage the condition.
Treatment tends to involve making healthful lifestyle changes, such as quitting smoking, adopting a healthful diet, and getting regular exercise.
However, some people may need to take medications or undergo medical procedures.
Medications that people can take to reduce the risk or impact of CHD include:
- Beta-blockers: A doctor may prescribe beta-blockers to reduce blood pressure and heart rate, especially among people who have already had a heart attack.
- Nitroglycerin patches, sprays, or tablets: These widen the arteries and reduce the heart’s demand for blood, as well as soothe chest pain.
- Angiotensin-converting enzyme inhibitors: These bring down blood pressure and help slow or stop the progression of CHD.
- Calcium channel blockers: These will widen the coronary arteries, improving blood flow to the heart and reducing hypertension.
- Statins: These may have a positive impact on outcomes in CHD. One 2019 review found that although taking statins cannot reduce the overall risk of death from CHD, they can prevent development and reduce the risk of non-fatal heart attacks. However, they might not be effective for people with cholesterol disorders such as hyperlipidemia.
In the past, some people used aspirin to lower their risk of CHD, but current guidelines only recommend this for people with a high risk of heart attack, stroke, angina, or other cardiovascular events. This is because aspirin is a blood thinner, which increases a person’s risk of bleeding.
Doctors now recommend focusing on lifestyle strategies, such as adopting a healthful diet and getting regular moderate to intense exercise. These strategies can reduce the risk of atherosclerosis.
The following surgical procedures can open or replace blocked arteries if they have become very narrow, or if symptoms are not responding to medications:
- Laser surgery: This involves making several very small holes in the heart muscle. These encourage the formation of new blood vessels.
- Coronary bypass surgery: A surgeon will use a blood vessel from another part of the body to create a graft that bypasses the blocked artery. The graft may come from the leg, for example, or an inner chest wall artery.
- Angioplasty and stent placement: A surgeon will insert a catheter into the narrowed part of the artery and pass a deflated balloon through the catheter to the affected area. When they inflate the balloon, it compresses the fatty deposits against the artery walls. They may leave a stent, or mesh tube, in the artery to help keep it open.
On rare occasions, a person may need a heart transplant. However, this is only if the heart has severe damage and treatment is not working.
Controlling blood cholesterol levels can help reduce a person’s risk of CHD. To better control blood cholesterol levels:
- be more physically active
- limit alcohol intake
- avoid tobacco
- adopt a diet with less sugar, salt, and saturated fats
People who already have CHD should ensure that they control these factors by following the doctor’s recommendations.
The following factors increase a person’s risk of developing CHD:
- having high blood pressure, or hypertension
- having high levels of low-density lipoprotein, or “bad,” cholesterol
- having low levels of high-density lipoprotein, or “good,” cholesterol
- having a diagnosis of diabetes, in which the body cannot effectively remove sugar from the bloodstream
- having obesity
- smoking, which increases inflammation and increases cholesterol deposits in the coronary arteries
Some risk factors are not lifestyle-related. These may include:
- having high levels of the amino acid homocysteine, which one 2015 study linked to a higher incidence of CHD
- having high levels of fibrinogen, a blood protein that encourages the clumping of platelets to form blood clots
- having a family history of CHD
- for women, having been through menopause
- for men, being over 45 years of age
Having high levels of lipoprotein(a) specifically is also linked to a higher risk of cardiovascular disease and CHD.
A doctor can perform a physical examination, take a thorough medical history, and order a number of tests to diagnose CHD. For example:
- Electrocardiogram: This records the electrical activity and rhythm of the heart.
- Holter monitor: This is a portable device that a person wears under their clothes for 2 days or more. It records all the electrical activity of the heart, including the heartbeat.
- Echocardiogram: This is an ultrasound scan that monitors the pumping heart. It uses sound waves to provide a video image.
- Stress test: This may involve the use of a treadmill or medication that stresses the heart in order to test how it functions when a person is active.
- Coronary catheterization: A specialist will inject dye through a catheter they have threaded through an artery, often in the leg or arm. The dye shows narrow spots or blockages on an X-ray.
- CT scans: These help the doctor visualize the arteries, detect calcium within fatty deposits, and characterize any heart anomalies.
- Nuclear ventriculography: This uses tracers, or radioactive materials, to create an image of the heart chambers. A doctor will inject the tracers into the vein. The tracers then attach to red blood cells and pass through the heart. Special cameras or scanners trace the movement of the tracers.
- Blood tests: Doctors can run these to measure blood cholesterol levels, especially in people at risk of high blood cholesterol levels.
CHD develops when coronary arteries become too narrow. The condition causes blockages in the arteries that feed oxygen-rich blood to the heart.
CHD can be difficult to treat and may lead to a heart attack or stroke. However, people can take steps to reduce their risk of CHD by getting regular exercise, adopting a healthful diet, and avoiding or quitting tobacco.
People should seek immediate medical attention if they have chest pain and breathlessness, as this could indicate a heart attack.
Is CHD the most dangerous cardiovascular disease?
CHD is the most dangerous cardiovascular disease, as it causes the most deaths of any heart disease in the United States.
Having undetected or untreated high blood pressure or high cholesterol can lead to a heart attack without causing any prior symptoms. Be sure to see a doctor regularly and seek regular blood tests.
Even those who consider themselves to be healthy may have high cholesterol and not know it.Debra Sullivan, PhD, MSN, RN, CNE, COI Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.