Acute

Having a short and relatively severe course of symptoms with a sudden onset.

Acute Myocardial Infarction (AMI)

Also known as a heart attack. Where there is insufficient blood supply to the heart muscle that causes chest pain and death or damage of heart muscle.

Adverse effect

An unwanted action of a drug; a side effect.

Aetiology

The cause of the disease or disorder. Also spelt etiology (US).

Anticoagulant

A substance (such as a medicine) that is able to prevent coagulation, or clotting, of the blood.

Angina

Attacks of chest pain caused by low oxygen in the heart muscles. Also called Angina Pectoris.

Antibody

A substance produced by the body to act against substances foreign to the body, usually as part of an immune response to an infection or allergy. In some situations they are produced inappropriately and act against body tissues instead of foreign substances, resulting in an autoimmune condition.

Antiphospholipid Antibody

An antibody associated with some autoimmune conditions. This antibody causes increased and unwanted blood clot formation.

Antiplatelet

A substance that inhibits platelets in the blood sticking together.

Antithrombin III deficiency

A genetic deficiency of a substance that inhibits blood clotting. This deficiency causes increased blood clot formation.

Aorta

The large artery that carries blood from the heart to be supplied to the body.

Aortic valve

The heart valve that separates the aorta and the left side of the heart. It stops blood flowing back into the heart from the aorta.

Artificial Heart Valve

A valve that has been used to replace one of the heart's natural valves when it stopped working properly. May be a biological valve or a mechanical valve.

Asasantin^®

The brand name of a medicine used to reduce the risk of strokes through antiplatelet actions. Contains aspirin and dipyridamole.

Aspirin

An antiplatelet medicine used in low doses (between 75 and 150mg) to stop platelets sticking together and to reduce the risk of stroke and heart attack.

Asymptomatic

Producing no symptoms or without symptoms.

Atrial Fibrillation (AF)

Rapid uncoordinated contractions of the top chambers of the heart.

Atrium

One of the top chambers of the heart. Plural: atria

Autoimmune

Diseases and conditions where antibodies attack the bodies own tissues.