The heart is the pump responsible for circulating blood throughout the body. Myocardium (myo=muscle + cardium=muscle) is the heart muscle that contracts to pump that blood and like any other muscle, it requires oxygen rich blood for energy. Angina pectoris describes the pain, discomfort, or other symptoms that occur when blood flow to heart muscle cells is not enough to meet its energy needs.
The classic description of angina is a crushing pain that radiates across the chest, sometimes down the arm, into the neck, jaw or teeth, or into the back. It may be associated with shortness of breath, nausea, vomiting, sweating, and weakness.
Many patients do not use pain as a description for angina, instead describing the sensation as a fullness, tightness, burning, squeezing, or ache. The discomfort may be felt in the upper abdomen, between the shoulders, or in the back. The pain may be felt just in an arm, right, left or both, and may or may not be associated with other symptoms.
Angina is often brought on by exercise and activity and gets better with rest. When the body requires the heart to pump more blood, the heart muscle is asked to do more work and that can cause it to outstrip its energy supply. When the body rests, angina should start to subside.
Angina tends to progress slowly over time and patients may not recognize that their symptoms are due to heart disease. It may be fatigue and exercise intolerance, the gradually inability to perform work or other activities that had once been easier to do. It may be shortness of breath with activity like walking up steps or uphill. It is worrisome when the pain comes on at rest or at sleep, since it means that little activity is causing enough stress to cause angina symptoms.
This is the same situation that occurs when muscles in the leg or arm fatigue because of overuse and they begin to ache. The difference is that one can stop lifting or running but the heart cannot stop beating to rest. The other difference is that the symptoms of angina are felt in different ways by different patients and may not be recognized as coming from the heart.
Unfortunately for some patients, they may have no symptoms at all, even with significant narrowing of their coronary arteries, and they may first present for care in the midst of a myocardial infarction or heart attack. This is especially true for women who may have atypical angina symptoms including fatigue, malaise, weakness, and dizziness.
Angina is a warning sign that the heart muscle is not getting adequate blood supply and oxygen. If unheeded it may lead to a heart attack or myocardial infarction (myo=muscle + cardium=heart + infarct=death).