ANGINA PECTORIS

BACKGROUND

Angina is chest pain or discomfort caused when your heart muscle doesn't get enough oxygen-rich blood. It may feel like pressure or squeezing in your chest. The discomfort also can occur in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion.

Angina isn’t a disease on its own, but rather a symptom of coronary heart disease (CHD). CHD is one of the most common types of heart disease in adults, which occurs when a substance called plaque builds up around the inner walls of the arteries of your heart. This causes the arteries of the heart to become narrower. Since these arteries primarily carry oxygen to the heart through the bloodstream, the supply of oxygen to the heart then becomes restricted, causing tightness in the chest. Angina may also be a symptom of coronary micro vascular disease (MVD), which affects the smallest coronary arteries and is more commonly prevalent amongst women.

DISEASE OCCURRENCE IN POPULATION

In Pakistan, mortality from coronary heart disease is 410/100000. Low and middle income countries including the South Asian countries of India and Pakistan contribute significantly to the global burden of cardiovascular diseases accounting for 75% of all deaths and 86.3% of all loss of disability adjusted life years attributable to this cause.

RISK FACTORS

The following risk factors increase your risk of coronary artery disease and angina.

TOBACCO USE: Chewing tobacco, smoking and long-term exposure to secondhand smoke damage the interior walls of arteries including arteries to your heart, allowing deposits of cholesterol to collect and block blood flow.

DIABETES: Diabetes is the inability of your body to produce enough insulin or respond to insulin properly. Insulin, a hormone secreted by your pancreas, allows your body to use glucose, which is a form of sugar from foods. Diabetes increases the risk of coronary artery disease, which leads to angina and heart attacks by speeding up atherosclerosis.

HIGH BLOOD PRESSURE: Blood pressure is determined by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. Over time, high blood pressure damages arteries.

HIGH BLOOD CHOLESTEROL OR TRIGLYCERIDE LEVELS: Cholesterol is a major part of the deposits that can narrow arteries throughout your body, including those that supply your heart. A high level of the wrong kind of cholesterol, known as low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol), increases your risk of angina and heart attacks. A high level of triglycerides, a type of blood fat related to your diet, also is undesirable.

HISTORY OF HEART DISEASE: If you have coronary artery disease or if you've had a heart attack, you're at a greater risk of developing angina.

OLDER AGE:Men older than 45 and women older than 55 have a greater risk than do younger adults.

LACK OF EXERCISE: An inactive lifestyle contributes to high cholesterol, high blood pressure, type 2 diabetes and obesity. However, it is important to talk with your doctor before starting an exercise program.

OBESITY: Obesity raises the risk of angina and heart disease because it's associated with high blood cholesterol levels, high blood pressure and diabetes. Also, your heart has to work harder to supply blood to the excess tissue.

STRESS: Stress can increase your risk of angina and heart attacks. Too much stress, as well as anger, can also raise your blood pressure. Surges of hormones produced during stress can narrow your arteries and worsen angina.

SIGN AND SYMPTOMS

You may confuse angina pain with indigestion, as the symptoms are similar. However, you need to be careful in assessing the difference between the two as angina can be fatal. You need to look out for these common symptoms of angina:

• Chest pain
• Pain in the jaw, neck and shoulders
• Shortness of breath
• Sweating
• Constant fatigue
• Dizziness
• Nausea
• Vomiting

These symptoms are important if they last more than a few minutes or keep happening over and over (coming and going). If you think you might be having a heart attack, call for an ambulance right away. Do not try to get to the hospital on your own.

DIAGNOSITIC TEST

To diagnose angina, your doctor will start by doing a physical exam and asking about your symptoms. You'll also be asked about any risk factors, including whether you have a family history of heart disease.

There are several tests your doctor may order to help confirm whether you have angina:

ELECTROCARDIOGRAM (ECG OR EKG): An electrocardiogram traces the electrical signals that cause your heart to beat as they travel through your heart. Your doctor can look for patterns among these heartbeats to see if the blood flow through your heart has been slowed, interrupted or if you're having a heart attack.

STRESS TEST: Sometimes angina is easier to diagnose when your heart is working harder. During a stress test, you exercise by walking on a treadmill or pedaling a stationary bicycle. While exercising, your blood pressure is monitored and your ECG readings are watched. If you're unable to exercise, you may be given drugs that cause your heart to work harder to simulate exercising.

ECHOCARDIOGRAM: An echocardiogram uses sound waves to produce images of the heart. Your doctor can use these images to identify whether there are areas of your heart muscle that have been damaged by poor blood flow, a cause of angina. An echocardiogram is sometimes given during a stress test.

NUCLEAR STRESS TEST: A nuclear stress test helps measure blood flow to your heart muscle at rest and during stress. It is similar to a routine stress test, but during a nuclear stress test, a radioactive substance is injected into your bloodstream. This substance mixes with your blood and travels to your heart. A special scanner, which detects the radioactive material in your heart, creates images of your heart muscle. Inadequate blood flow to any part of your heart will show up as a light spot on the images.

CHEST X-RAY: This test takes images of your heart and lungs. This is to look for other conditions that might explain your symptoms and to see if you have an enlarged heart.

BLOOD TESTS: Certain heart enzymes slowly leak out into your blood if your heart has been damaged by a heart attack. Samples of your blood can be tested for the presence of these enzymes.

CORONARY ANGIOGRAPHY: Coronary angiography uses X-ray imaging to examine the inside of your heart's blood vessels. It's part of a general group of procedures known as cardiac catheterization. During coronary angiography, a type of dye that's visible by X-ray machine is injected into the blood vessels of your heart. The X-ray machine rapidly takes a series of images (angiograms), offering a detailed look at your blood vessels.

CARDIAC COMPUTERIZED TOMOGRAPHY (CT) SCAN: In a cardiac CT scan, you lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of your heart and chest, which can show if any of your heart's arteries are narrowed or if your heart is enlarged.

TREATMENT OPTIONS

There are many options for angina treatment, including lifestyle changes, medications, angioplasty and stenting, or coronary bypass surgery. The goals of treatment are to reduce the frequency and severity of your symptoms and to lower your risk of heart attack and death.

MEDICATIONS

NITRATES: Nitrates are often used to treat angina. Nitrates relax and widen your blood vessels, allowing more blood to flow to your heart muscle. You might take a nitrate when you have angina-related chest discomfort, before doing something that normally triggers angina (such as physical exertion), or on a long-term preventive basis. The most common form of nitrate used to treat angina is with nitroglycerin tablets put under your tongue.

ASPIRIN: Aspirin reduces the ability of your blood to clot, making it easier for blood to flow through narrowed heart arteries. Preventing blood clots can also reduce your risk of a heart attack. But don't start taking a daily aspirin without talking to your doctor first.

BETA BLOCKERS: Beta blockers work by blocking the effects of the hormone epinephrine, also known as adrenaline. As a result, the heart beats more slowly and with less force, thereby reducing blood pressure. Beta blockers also help blood vessels relax and open up to improve blood flow, thus reducing or preventing angina.

STATINS: Statins are drugs used to lower blood cholesterol. They work by blocking a substance your body needs to make cholesterol. They may also help your body reabsorb cholesterol that has accumulated in plaques in your artery walls, helping prevent further blockage in your blood vessels. Statins also have many other beneficial effects on your heart arteries.

CALCIUM CHANNEL BLOCKERS:  Calcium channel blockers, also called calcium antagonists, relax and widen blood vessels by affecting the muscle cells in the arterial walls. This increases blood flow in your heart, reducing or preventing angina.

NICORANDIL: a potassium channel activator is used for the treatment of angina in a number of countries. It has multiple actions that are beneficial in coronary artery disease. It is an arterial and venous dilator and improves coronary blood flow due to potassium channel opening and nitrate effect. Since ATP-dependent potassium channels play a role in ischemic preconditioning, nicorandil may also mimic a natural process of ischemic preconditioning, protecting the heart from subsequent ischemic attacks.

RANOLAZINE: Ranolazine can be used alone or with other angina medications, such as calcium channel blockers, beta blockers or nitroglycerin.

MEDICAL PROCEDURES AND SURGERY

Medication and lifestyle changes are frequently used to treat stable angina. But procedures, such as angioplasty, stenting and coronary artery bypass surgery, also are used to treat angina.

ANGIOPLASTY AND STENTING: During an angioplasty [also called a percutaneous coronary intervention (PCI)] a tiny balloon is inserted into your narrowed artery. The balloon is inflated to widen the artery, and then a small wire mesh coil (stent) is usually inserted to keep the artery open. This procedure improves blood flow in your heart, reducing or eliminating angina.

CORONARY ARTERY BYPASS SURGERY: During coronary artery bypass surgery, a vein or artery from somewhere else in your body is used to bypass a blocked or narrowed heart artery. Bypass surgery increases blood flow to your heart and reduces or eliminates angina.

PRECAUTIONS

• If you smoke, stop smoking. Avoid exposure to secondhand smoke.
• Eat a healthy diet with limited amounts of saturated fat, lots of whole grains, and many fruits and vegetables.
• Talk to your doctor about starting a safe exercise plan.
• If you're overweight, talk to your doctor about weight-loss options.
• Treat diseases or conditions that can increase your risk of angina, such as diabetes, high blood pressure and high blood cholesterol.
• Because angina is often brought on by exertion, pace yourself and take rest breaks.
• Avoid large meals that make you feel overly full.

Try to find ways to relax. Talk with your doctor about stress-reduction techniques.