Oxygen Supply to the Heart Is Blocked

Angina is a symptom of a heart condition known as myocardial ischemia. Simply put, angina occurs when the coronary arteries cannot supply the heart with enough oxygen-rich blood to meet its needs. The symptoms of angina are usually chest pain or pressure and most often appear when the heart requires more oxygen than usual, such as during exercise or a period of stress. Angina symptoms disappear after the patient rests or takes nitroglycerin. This type of angina is known as stable angina. Unlike a heart attack, angina does not cause permanent damage to the heart muscle, but it is a warning symptom of a temporary lack of oxygen to the heart tissue that should be carefully investigated by a physician to determine its cause and treatment. There are different kinds of angina that do not follow the classic pattern described above. Angina that occurs while the patient is at rest is known as variant or Prinzmetal’s angina. Variant angina is caused by a spasm in one or more of the coronary arteries, usually a result of atherosclerosis (hardening of the arteries). Another common type of angina is unstable angina, in which stable angina occurs more frequently and may not be relieved by rest or medication. Unstable angina can occur at rest or during exercise or stress. Patients with angina should be aware of their symptoms and contact their physician if these symptoms change or worsen.

Be Aware of Symptoms

Angina is not a disease but a symptom of a condition (ischemia) in which the heart muscle (myocardium) does not get enough oxygenated blood to do its work. There could be several reasons for this, but the most common is a blockage of the coronary arteries due to atherosclerosis. For most patients, angina symptoms occur only when the heart needs more oxygen than usual. This situation can occur during exercise, with stress or strong feelings, during extremes in temperature or altitude, after a heavy meal, or while smoking. Most angina attacks occur between 6 am and noon.

Classic symptoms:

Angina is a common cardiac condition affecting more than six million Americans. More than a half million patients are newly diagnosed each year. Patients at higher risk for angina are those with a family history of the disease, high risk for atherosclerosis, hypertension, high cholesterol, diabetes, or who smoke.

Patients with symptoms of angina often describe an ache or pressure in the chest just below the breast bone. This sensation can move to the left shoulder and arm, up into the jaw or teeth, through the back, or, less often, down the right arm. It usually begins with exercise, especially after one has eaten. It may also occur when walking out of a warm room into cold weather or wind. Angina pain can even be triggered by an intense emotion, such as fear or anger, or during sleep while dreaming. The symptoms of angina may cause the patient to fear a heart attack, but with classic, stable angina, chest pain goes away after rest or upon taking nitroglycerin under the tongue.

Diagnosis:

The diagnosis is made using information from the patient’s history, a physical examination, and a variety of tests that can show the degree of myocardial ischemia in the heart muscle. For many patients, testing begins with an exercise stress EKG, or stress echocardiogram test. More invasive tests such as coronary angiography can provide detailed information about the amount of coronary artery blockage. Blood flow through the heart can be seen using sophisticated tomographic imaging (PET and SPECT scans). Treatment focuses on reducing the risk factors and preventing or reducing the ischemia to the heart. Smokers with angina should stop smoking, and high blood pressure should be treated to avoid added stress on the heart. Lowering cholesterol levels can prevent further coronary atherosclerosis. A well-designed exercise program is also desirable.

Drug therapy:

Types of drugs used to treat angina include nitrates, beta-blockers, and calcium channel blockers. Nitrates dilate coronary blood vessels and relax smooth muscles, helping to balance the heart’s demand for oxygen with the supply. The nitrates are available as short- and longacting formulations. Short-acting nitroglycerin is dissolved under the tongue (sublingual) for the quick relief of angina pain or pressure. Most patients begin to feel relief within one to three minutes. An additional tablet may be taken every five minutes for a total of three times. A short-acting oral spray is also available. These short-acting nitrates should be carried at all times so they are available in case of an attack, and a fresh supply should be ordered frequently to ensure potency. Long-acting nitrates, which are used to prevent angina attacks, include oral isosorbide, nitroglycerin ointment, and skin patches.