Angina

موضوع: Angina السبت نوفمبر 22, 2008 1:41 am

Angina pectoris

Angina is chest pain due to ischemia (a lack of blood and hence oxygen supply) of the heart muscle, generally due to obstruction or spasm of the coronary arteries (the heart's blood vessels). Coronary artery disease, the main cause of angina, is due to atherosclerosis of the cardiac arteries.

It is common to equate severity of angina with risk of fatal cardiac events. There is a weak relationship between severity of pain and degree of oxygen deprivation in the heart muscle (i.e. there can be severe pain with little or no risk of a heart attack, and a heart attack can occur without pain).

Worsening ("crescendo") angina attacks, sudden-onset angina at rest, and angina lasting more than 15 minutes are symptoms of unstable angina (usually grouped with similar conditions as the acute coronary syndrome). As these may herald myocardial infarction (a heart attack), they require urgent medical attention and are generally treated as a presumed heart attack.

Symptoms

- chest discomfort :

usually described as a pressure, heaviness, tightness, squeezing, burning, or choking sensation

- pain at epigastrium (upper central abdomen), back, neck, jaw, or shoulders.

- breathlessness, sweating

- nausea, vomiting and pallor.

risk factors

Major risk factors for angina include:

- cigarette smoking

- diabetes

- high cholesterol

- high blood pressure

- family history of premature heart disease.

Subtypes

Stable angina

This refers to the more common understanding of angina related to myocardial ischemia. Typical presentations of stable angina is that of chest discomfort and associated symptoms precipitated by some activity (running, walking, etc) with minimal or non-existent symptoms at rest. Symptoms typically about several minutes following cessation of precipitating activities and resume when activity resumes. In this way, stable angina may be thought of as being similar to claudication symptoms.

Unstable angina

Unstable angina (UA) may occur unpredictably at rest which may be a serious indicator of an impending heart attack. What differentiates stable angina from unstable angina (other than symptoms) is the pathophysiology of the atherosclerosis. In stable angina, the developing atheroma is protected with a fibrous cap. This cap (atherosclerotic plaque) may rupture in unstable angina, allowing blood clots to precipitate and further decrease the lumen of the coronary vessel. This explains why angina appears to be independent to activity.

Diagnosis

- electrocardiogram (ECG) .

- exercise ECG test.

- Echocardiography.

- coronary angiogram.

Treatment

* The main goals of treatment in angina pectoris are:

- relief of symptoms

- slowing progression of the disease

- and reduction of future events, especially heart attacks and of course death.

* Drug therapy:

- An aspirin (75 mg to 100 mg) per day

- Beta blockers (eg. carvedilol, propranolol, atenolol etc. are some few examples)

- short-acting nitroglycerin medications are used for symptomatic relief of angina.

- Calcium channel blockers (such as nifedipine (Adalat) and amlodipine)

- Isosorbide mononitrate and nicorandil are vasodilators commonly used in chronic stable angina

- If inhibitor: ivabradine provides pure heart rate reduction,.[1] leading to major anti-ischemic and antianginal efficacy

- ACE inhibitors are also vasodilators

- statins are the most frequently used lipid/cholesterol modifiers which probably also stabilise existing atheromatous plaque

- anti anginal drug as Ranolazine.

* general treatment:

- gentle and sustained exercise rather than dangerous for improving blood pressure and promoting coronary artery collateralisation.

- Identifying and treating risk factors for further coronary heart disease is a priority in patients with angina. This means testing for elevated cholesterol and other fats in the blood, diabetes and hypertension (high blood pressure), encouraging stopping smoking and weight optimisation.