Angina Pectoris Causes,Epidemiology,Symptoms,Warning,Differential diagnosis and Emergency aid.

Angina pectoris
Causes:

• Angina occurs when myocardial demand for oxygen exceeds the ability of the coronary arteries to supply oxygenated blood. The cause is usually coronary artery obstruction due to atherosclerosis. 
• The most common form of the condition is stable angina. It is brought on by physical exertion or other forms of stress, including exposure to cold, heavy meals or intense emotion, and is relieved by rest.
• Unstable angina is a syndrome of attacks of increasing frequency and severity, occurring on minimal exertion or at rest. It often leads to MI.

Epidemiology
About 1.2 million people in the UK have or have had angina – 9% of men and 5% of women aged 55–64, and 14% of men and 8% of women aged 65–74.
Symptoms and warning signs

• The patient may experience a sensation in the centre of the chest variously described as pressure, fullness, squeezing, tightness, burning or a heavy weight.
• It may also manifest as pain in the epigastric region, back or jaw, and may radiate to the shoulders, neck or arms.
• Pain ranges in intensity from mild to severe.
• Other symptoms, as occur with MI (see above), may be experienced.
• Unlike MI, pain is reversible on rest; attacks last only a few minutes and are relieved by coronary vasodilators.

Differential diagnosis
As for MI, but may be more diffi cult to distinguish from other conditions causing pain and other symptoms in the chest and epigastric region.
Emergency aid

• Sit the person down in a quiet area, make the patient comfortable and reassure.
• Allow the person to use any coronary vasodilator medication he or she is carrying. (If the individual has no medication but confi rms that he or she has angina, you may give a glyceryl trinitrate tablet or similar medication.)
• Allow the person to rest until the attack is over.