Lexicon – Interventional Imaging
Anaphylactic shock
A sudden onset severe allergic reaction after contact with an allergising agent or allergen, to which the body has already been sensitised. This may be a food or medicine or an insect bite etc.
It results in circulatory failure, skin, respiratory and gastro-intestinal signs and can cause shock. It is one of the major reasons for urgent medical intervention.

Atheromatous plaque
Thickening of the arterial wall due to an accumulation of lipid, fibrin and calcium. The term atherosclerosis is also used. These plaques have an increasing tendency to develop with advancing age and over time narrow the diameter of the coronary artery to an ultimate stage where the occlusion may become complete and permanent.

A chronic multi-factorial disease involving thickening of the wall of the artery due to accumulation of lipids, fibrin and calcium which form plaques of atheroma. These plaques have an increasing tendency to develop with advancing age and over time narrow the diameter of the coronary artery to a point where the obstruction may become complete and permanent.

Cardiogenic shock
The situation in which the heart is no longer able to inject blood correctly and no longer carries out its function as a pump. The tissues are not then correctly perfused.
A small diameter tube introduced into the groin or wrist. It is advanced from the radial or femoral artery to the entrance of the coronary arteries. 

Coronary angioplasty
A mini-invasive procedure which involves inflating a balloon which may or may not be connected to a stent, in the narrowing of a coronary artery in order to return the artery to its initial diameter.
Coronary artery by-pass
A surgical procedure involving bypassing the stenosed artery.

Coronary restenosis
Renarrowing of the diameter of a coronary artery where the stent has been positioned. This defect is due to excessive scarring of the arterial wall.

Coronary stenosis
Narrowing of the diameter of a coronary artery due to thickening of the arterial wall. This is due to the presence of atheromatous plaques formed by an accumulation of lipids, fibrin and calcium. The term atherosclerosis is also used.

A chronic disease which develops when the pancreas does not produce enough insulin or that the body does not use the insulin which it produces correctly. Insulin is a hormone which regulates the sugar concentrations in the blood. Hyperglycaemia or a raised concentration of sugar in the blood is a common defect of uncontrolled diabetes which over time leads to serious damage to many organ systems, particularly nerves and blood vessels.

A paper trace recording the electrical activity of the heart.

Glyceryl trinitrate (or trinitrin)
A rapid acting medicine which dilates the coronary artery (vasodilator), increasing coronary artery blood flow and reducing blood pressure. 

A disease involving high levels of cholesterol in the blood. These high levels may predispose to the development of atherosclerosis. There is no specific treatment for the disease although it can be controlled by dietary measures.

After smoking and before alcoholism, hypertension is the second leading factor which reduces the number of years in good health. It increases cardiovascular morbidity and mortality and is a direct risk factor for coronary atherosclerosis, heart failure, left ventricular hypertrophy, damage to the endothelium, cerebrovascular accidents, angina pectoris and reduced coronary vasodilatation reserve. It is also a separate disease in itself which mostly affects the brain, heart and kidneys. The term hypertension is used in adults when blood pressure readings are 140/90 mmHg or over.

Intravenous catheter
A short tube introduced into a vein in order to allow medicine to be administered.

Myocardial infarction
The direct result of the blood and oxygen supply to an area of the heart being stopped as a result of obstruction of a coronary artery. The cardiac cells in the area affected die.

Myocardial ischaemia
An interruption of the blood supply, and therefore oxygen supply to a coronary artery causing death of cardiac cells in the area affected. This stoppage in blood circulation leads to a myocardial infarction.

The muscle tissue forming the heart.

Obstruction of a coronary artery
Complete interruption of blood flow either from the formation of a fresh clot (thrombus) which is acute coronary artery obstruction, or the progression of atheromatous plaques, which is chronic coronary artery obstruction.

Renal insufficiency (or renal impairment)
Chronic renal insufficiency is a serious disease which causes a gradual and irreversible decline in the ability of the kidneys to filter blood and excrete some hormones. Metabolic products and excess water pass increasingly less into the urine and accumulate in the blood. Acute renal failure occurs suddenly, occasionally after an accident or following a difficult surgical procedure. It often occurs after a reversible fall in renal blood flow.

Stent (or endoprosthesis)
A coronary stent or coronary endoprosthesis is a thin, cylindrical metal mesh which is placed inside coronary arteries to maintain their initial diameter. The stents are connected to a balloon which is positioned in the place to be treated and inflated producing the correct shape for the coronary stent. Stents are available which are impregnated with active substances, reducing the risk of restenosis.

In medical parlance, a symptom is something experienced by the patient (such as difficulty breathing) and it may be identified during the clinical history or clinical examination. This is different to a physical sign which is something observed by the doctor in the clinical examination.