Coronary heart disease

Coronary heart disease (CHD), also called coronary artery disease (CAD), ischaemic heart disease, atherosclerotic heart disease, is the end result of the accumulation of atheromatous plaques within the walls of the arteries that supply the myocardium (the muscle of the heart) with oxygen and nutrients. It is the leading cause of death in the U.S. While the symptoms and signs of coronary heart disease are noted in the advanced state of disease, most individuals with coronary heart disease show no evidence of disease for decades as the disease progresses before the first onset of symptoms, often a "sudden" heart attack, finally arise. After decades of progression, some of these atheromatous plaques may rupture and (along with the activation of the blood clotting system) start limiting blood flow to the heart muscle. The disease is the most common cause of sudden death, and is also the most common reason for death of men and women over 20 years of age.

Overview:
Atherosclerotic heart disease can be thought of as a wide spectrum of disease of the heart. At one end of the spectrum is the asymptomatic individual with atheromatous streaks within the walls of the coronary arteries (the arteries of the heart). These streaks represent the early stage of atherosclerotic heart disease and do not obstruct the flow of blood. A coronary angiogram performed during this stage of diseases may not show any evidence of coronary artery disease, because the lumen of the coronary artery has not decreased in calibre.

Atheromatous plaques that cause obstruction of less than 70 percent of the diameter of the vessel rarely cause symptoms of obstructive coronary artery disease. As the plaques grow in thickness and obstruct more than 70 percent of the diameter of the vessel, the individual develops symptoms of obstructive coronary artery disease. At this stage of the disease process, the patient can be said to have ischemic heart disease. The symptoms of ischemic heart disease are often first noted during times of increased workload of the heart. For instance, the first symptoms include exertional angina or decreased exercise tolerance.

As the degree of coronary artery disease progresses, there may be near-complete obstruction of the lumen of the coronary artery, severely restricting the flow of oxygen-carrying blood to the myocardium. Individuals with this degree of coronary heart disease typically have suffered from one or more myocardial infarctions (heart attacks), and may have signs and symptoms of chronic coronary ischemia, including symptoms of angina at rest and flash pulmonary edema.

Causes:
Research suggests that coronary artery disease (CAD) starts when certain factors damage the inner layers of the coronary arteries. These factors include:

* Smoking
* High amounts of certain fats and cholesterol in the blood
* High blood pressure
* High amounts of sugar in the blood due to insulin resistance or diabetes

When damage occurs, your body starts a healing process. Excess fatty tissues release compounds that promote this process. This healing causes plaque to build up where the arteries are damaged.

The buildup of plaque in the coronary arteries may start in childhood. Over time, plaque can narrow or completely block some of your coronary arteries. This reduces the flow of oxygen-rich blood to your heart muscle.

Plaque also can crack, which causes blood cells called platelets (PLATE-lets) to clump together and form blood clots at the site of the cracks. This narrows the arteries more and worsens angina or causes a heart attack.

Symptoms:
There are often no typical symptoms as they are well known for coronary heart disease; Cardiac Syndrome X often is a diagnosis of exclusion. However, the following list may be helpful in diagnosing the disease:

* Chest pain or Angina, quite often at rest; the pain may spread to the left arm or the neck, back, throat, or jaw. There might be present a numbness (paresthesia) or a loss of feeling in the arms, shoulders, or wrists. Patients with female-pattern coronary artery disease often have chest pain after they exercise and a very variable duration of angina episodes.
* Coronary angiography demonstrates “normal” coronary arteries, i. e. no blockages or stenoses can be detected in the larger epicardial vessels.
* No inducible coronary artery spasm present during cardiac catheterization.
* Characteristic ischemic ECG changes during exercise testing.
* ST segment depression and angina in the absence of left ventricular wall motion abnormalities during pharmacological stress test.
* Reduction of platelet aggregation after exercise (aggregation time 10 seconds).
* Inconstant or partial response to sublingual nitrates.
* Absence of cardiac or systemic diseases potentially associated with microvascular dysfunction.
* Postmenopausal or menopausal status.
* Impaired quality of life.

The diagnosis of “Cardiac Syndrome W” - female-pattern coronary artery disease often is, as mentioned, an “exclusion” diagnosis. Therefore, usually the same tests are used as in any patient with the suspicion of coronary heart disease:

* Baseline ECG
* Exercise ECG – Stress test
* Exercise radioisotope test (nuclear stress test, myocardial scintigraphy).
* Echocardiography (including stress echocardiography).
* Coronary angiography.
* Intravascular ultrasound.
* MRI scan.

Diagnosis:
EKG (Electrocardiogram)- An EKG is a simple test that detects and records the electrical activity of your heart. An EKG shows how fast your heart is beating and whether it has a regular rhythm. It also shows the strength and timing of electrical signals as they pass through each part of your heart. Certain electrical patterns that the EKG detects can suggest whether CAD is likely. An EKG also can show signs of a previous or current heart attack.

Echocardiography- This test uses sound waves to create a moving picture of your heart. Echocardiography provides information about the size and shape of your heart and how well your heart chambers and valves are working. The test also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and previous injury to the heart muscle caused by poor blood flow.

Chest X Ray- A chest x ray takes a picture of the organs and structures inside the chest, including your heart, lungs, and blood vessels. A chest x ray can reveal signs of heart failure, as well as lung disorders and other causes of symptoms that aren't due to CAD.

Blood Tests- Blood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels may show that you have risk factors for CAD.
Coronary Angiography and Cardiac Catheterization- Your doctor may ask you to have coronary angiography if other tests or factors show that you're likely to have CAD. This test uses dye and special x rays to show the insides of your coronary arteries.
To get the dye into your coronary arteries, your doctor will use a procedure called cardiac catheterization. A long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is then threaded into your coronary arteries, and the dye is released into your bloodstream. Special x rays are taken while the dye is flowing through your coronary arteries.
Cardiac catheterization is usually done in a hospital. You're awake during the procedure. It usually causes little to no pain, although you may feel some soreness in the blood vessel where your doctor put the catheter.

Treatment:
Making lifestyle changes can often help prevent or treat CAD. For some people, these changes may be the only treatment needed:

* Follow a heart healthy eating plan to prevent or reduce high blood pressure and high blood cholesterol and to maintain a healthy weight
* Increase your physical activity. Check with your doctor first to find out how much and what kinds of activity are safe for you.
* Lose weight, if you're overweight or obese.
* Quit smoking, if you smoke. Avoid exposure to secondhand smoke.
* Learn to cope with and reduce stress.

You also should have less than 200 mg a day of cholesterol. The amounts of cholesterol and the different kinds of fat in prepared foods can be found on the Nutrition Facts label.

Foods high in soluble fiber also are part of a healthy eating plan. They help block the digestive track from absorbing cholesterol. These foods include:

* Whole grain cereals such as oatmeal and oat bran.
* Fruits such as apples, bananas, oranges, pears, and prunes.
* Legumes such as kidney beans, lentils, chick peas, black-eyed peas, and lima beans.

A diet high in fruits and vegetables can increase important cholesterol-lowering compounds in your diet. These compounds, called plant stanols or sterols, work like soluble fiber.

Fish are an important part of a heart healthy diet. They're a good source of omega-3 fatty acids, which may help protect the heart from blood clots and inflammation and reduce the risk for heart attack. Try to have about two fish meals every week. Fish high in omega-3 fats are salmon, tuna (canned or fresh), and mackerel.

You also should try to limit the amount of sodium (salt) that you eat. This means choosing low-sodium and low-salt foods and "no added salt" foods and seasonings at the table or when cooking. The Nutrition Facts label on food packaging shows the amount of sodium in the item.

Try to limit alcoholic drinks. Too much alcohol will raise your blood pressure and triglyceride level. (Triglycerides are a type of fat found in the blood.) Alcohol also adds extra calories, which will cause weight gain. Men should have no more than two alcoholic drinks a day. Women should have no more than one alcoholic drink a day.

Regular physical activity can lower many CAD risk factors, including LDL ("bad") cholesterol, high blood pressure, and excess weight. Physical activity also can lower your risk for diabetes and raise your levels of HDL cholesterol (the "good" cholesterol that helps prevent CAD).

Therapeutic options for coronary heart disease today are based on three principles:

1. Medical treatment- drugs, e.g. nitroglycerin, beta-blockers, calcium antagonists, etc.
2. Coronary interventions as angioplasty and stent-implantation.
3. Coronary artery bypass grafting (CABG - coronary artery bypass surgery). Recent research efforts focus on new angiogenic treatment modalities (angiogenesis) and various (adult) stem cell therapies.