Glossary Of Terms - I

Idiosyncratic reaction Immune system Immunisation Impairment ICD implantable cardio-defibrillator Implantable loop recorder under event
Incision Inert substances drugs Infarct Inflammation In-patient Insulin
Insurance Interact interaction Intercostal Internal mammary artery INR International Normalized Ratio Intervention
Intravenous infusion Ischaemic heart disease IHD ISMO isosorbide mononitrate -itis

Ibuprofen is a non-steroidal anointing drug (=NSAID). It has fewer side effects than some other NSAIDs. Unlike aspirin, it usually does not cause stomach bleeding. It is available as tablets, and also as a cream to be applied to the skin for muscle pains.
It reduces pain, stiffness and inflammation. It is often used for treating osteoarthritis, rheumatoid arthritis, and gout. Some people take it to relieve headache including migraine, menstrual pain, dental pain, and injuries.

The maximum safe dose of 200mg ibuprofen is one tablet every four hours, or at least four hours apart. Alternatively two tablets may be taken every eight hours. Thus the maximum safe dose is 6 tablets in 24 hours. As explained under paracetamol, ibuprofen and paracetamol can both be taken (at correct maximum doses and timings) together as they do not interact.

Ibuprofen should not be given to children under 12.

Brand names of ibuprofen, which is a generic name: Arthrofen, Brufen, Calprofen, Ebufac, Ibugel, Ibumousse, Ibuleve, Nurofen, and many others. Also junior brands for children. Ibuprofen is also used in the following drugs that are combinations: Codafen, Cuprofen Plus, Nurofen Plus, Solpaflex.

Side effects of ibuprofen include: heartburn / indigestion; and rarely: nausea, vomiting, swollen feet and/or ankles, ringing in the ears, rash, wheezing, breathlessness, black or bloodstained faeces, abdominal pain, dizziness, headache, sleepiness.

ICD See Implantable cardio-defibrillator and Automatic ICD under Automatic.

Idiosyncratic reaction. An unexpected adverse effect that occurs at the first use of a particular drug by a particular patient, and unrelated to the amount of the dose. People vary (eg genetically and/or having or not having a particular enzyme) so it can occur for one patient and not another.

IHD. See Ischaemic heart disease.

ILR. See implantable loop recorder under event.

IMA. See Internal Mammary Artery.

Immune system. The immune system is the body mechanism that produces antibodies when any foreign substance has been detected – eg from taste, touch, breathing, injury, or injection. The result may show as skin reddening, swelling, itching, and/or other allergic reactions.

Immunisation is a process to produce immunity as a preventive. See vaccine.

Impairment. People have an implicit belief that impairment causes disability. Impairment is the extent of the damage or disease – eg damage to the heart muscle or blockage in the arteries.

Disability is the difference from age-adjusted ‘normal’ – eg amount of angina, loss of mobility, quality of life.

Handicap is societal effects – eg driving licence, insurance.

Many people wrongly think that impairment is proportional to disability. For heart disease there is often little or no relationship between the amount of blockage in the coronary arteries and the patient's symptoms.

Implantable cardio-defibrillator, ICD. An ICD is a small electronic device implanted under the skin that continuously monitors the heart beats, and automatically reverts the heartbeat to a normal rhythm and/or does defibrillation whenever needed. The wire to electrically control the heart may be routed through a vein. This device is often fitted to patients with very fast heart rate, which could cause them to faint or cause their heart to stop beating. Compare Artificial pacemaker. See also Automatic ICD under Automatic.

Who should get ICD after a heart attack
Better therapies over the last 25 years have improved survivals during the acute phase and the early-convalescent phase (the first 24 to 48 hours) after a myocardial infarction (MI, blockage of a coronary artery causing destruction of some heart muscle).
A new research finding1 is that after the early-convalescent phase patients have a delayed increase in the risk of sudden death from cardiac causes. The research showed that patients with both:
- a history of heart attacks with myocardial infarction; and
- reduced ejection fraction (the volume of blood pumped out at each heartbeat divided by the maximum volume of the left ventricle – normal is about 55%, ‘reduced’ here means 35% or lower)
have increased risk of a life-threatening ventricular arrhythmia (wrong left ventricle pattern) so may benefit from having an ICD.
Various factors determine which patients are most likely to benefit from implantation of an ICD. The risk of sudden death after a myocardial infarction is highest during the first 12 months after the infarction and then declines. Patients with a history of heart failure and with an ejection fraction of generally less than 35% are more likely to benefit from an ICD.
- Those who after a myocardial infarction have an ejection fraction over 35% are not currently considered to be candidates for ICD implantation.
- For those between 25% and 35% other factors affect whether to implant an ICD – eg history of heart failure, documented non-sustained or inducible ventricular tachycardia, and a prolonged duration of the QRS interval on an ECG (the QRS is the big spike that corresponds to the left ventricle pumping out blood to the body).
- Patients with ejection fractions of 25% or less in the presence of appropriate modifying factors are generally considered suitable candidates for ICD.

See also S-ICD.

Incision means a cut. Eg a small cut in the skin to insert a catheter into a femoral artery; or a cut through the sternum for heart surgery. 

Inert. See Inert under Drug.

Infarct means roughly the same as a heart attack. Strictly it means a localised area of dead tissue resulting from obstruction of the blood supply to the relevant part, especially by an embolus.

Inferior means lower in quality or value; or situated beneath or lower in position. Opposite of Superior.

Inflammation is the reaction of living tissue to infection and/or injury – giving redness, swelling and/or pain.

In-patient is a patient in hospital for more than a day.

Institute of Food Research, IFR. They research issues relevant to food and human health – working to provide the underpinning science for consumers, policy makers, food industry, and academia. They have researched the benefits of An apple a day. They are funded by BBSRC. Next to Human Nutrition Unit on Norwich Research Park. Press Office tel is 01603 251490.

Insulin is a protein hormone made in the pancreas, which is on the left at about waist level. It controls the concentration of glucose in the blood and helps glucose enter cells for use as fuel. It helps convert sugars in carbohydrates into fuel for the body, and helps convert excess sugars into fat. Deficiency of insulin produces diabetes mellitus. Some diabetics may need insulin, which can be as an injection.

Insurance. Unique Insurance Services in partnership with The British Cardiac Patients Association provide home insurance for people affected by heart disease as well as supporters of the charity. You'll usually be able to receive at least a 10% discount off your current renewal premium, subject to underwriting criteria. Not only that, BCPA receives a donation, so you could be saving and giving money at the same time.
Unique and BCPA can provide additional benefits, without compromising competitive prices. These additional benefits include but are not limited to:
- prescribed medication in your refrigerator or freezer
- access ramps, stair lifts, through floor lifts, handrails, bathing/bedroom equipment
- damage to the home caused by forced access to attend a medical emergency.
To take advantage of this Unique Insurance, call for a quotation on 01603 828 246, or for more information see the Home insurance page on the BCPA website.
Unique are able to offer you Travel, Life, Motor, Annuities, Funeral Planning, Estate Planning and Equity Release – giving you choice, value and peace of mind.
Unique is a trading name of Heath Lambert Limited, which is authorised and regulated by the Financial Services Authority. Registered Office: 133 Houndsditch, London EC3A 7AH. Registered No: 1199129 England & Wales. Also see their adverts on the back pages of BCPA journals.
See also Life expectancy, pensions.

Interact. Interaction between pairs of drugs and/or medicines may occur. This means one does not work or produce its desired effects when in the presence of the other; and/or when taken together they have undesirable side effects. See also Inert under Drug.

Intercostal muscles and tissues are those between the ribs.

Internal mammary artery, IMA. An artery in the chest, to supply blood to the breast. You have two – left and right – LIMA, RIMA. May be used in a Coronary artery bypass graft. See artery and mammary.

International Normalized Ratio, INR, is a measure of the clotting property and viscosity of blood – in the sense that thick sticky blood is more likely to clot, and thin blood to bleed more. The measure helps decide how much anticoagulant may be needed. It measures the time taken for the blood to clot. The norm value is 1 for a healthy person not on an anticoagulant.

Intervention implies using a decisive role or action to change something. The aim is to modify what will happen, the way it happens, and/or the likely outcome. This can include disturbing, accelerating, or hindering the process.

Intravenous infusion, also called a drip, is a slow injection of a fluid into a vein.

Invert sugar is a mixture of fructose and glucose obtained by the inversion of sucrose. See under sugar.

Involuntary means carried out without any conscious wish to do whatever; or unintentional. See nerve.

Ion see ion under organic chemistry.

Iron and iron tablets. Iron is essential in forming red blood cells, which contain 2/3 of the iron in the body. It is a vital component of haemoglobin, which carries oxygen in the blood. Iron is also used in creating myoglobin, which stores oxygen in muscles for use in exercise. It is also essential in several enzymes, and involved in the use of oxygen by cells and the conversion of blood sugar to energy.

Iron tablets are available without prescription, with names: ferrous fumarate, ferrous gluconate, ferrous sulphate, and others. Some of these may have a coating to help the taste. Any overdose of iron tablets is very dangerous, and immediate medical attention is needed.

Iron deficiency is called anaemia.

Ischaemic heart disease, IHD, means an inadequate supply of blood to the heart or a part of the heart muscles, usually from obstructed blood flow. Strictly, ischaemia (or ischemia) means an inadequate supply of blood to an organ or part. IHD is used as the generic term in death statistics - see death rates. For IHD see coronary heart disease.

-itis means an inflammation of or a disease of.

Isosorbide mononitrate, ISMO. See Isosorbide mononitrate under Nitrates.

Isotope see isotope under organic chemistry.

iv = intravenous. See Intravenous infusion.

IVC. See Vena cava.


This information was created and edited by Richard Maddison for the BCPA.
Copyright © 1997-2019 The British Cardiac Patients Association, and/or Richard Maddison.
BCPA Head Office: 15 Abbey Road, Bingham, Nottingham NG13 8EE
Reg Charity 289190. Email:

First published in this form 2002, and updated 2005, 2007, 2008, 2011, 2012, 2013, 2017.
All rights reserved. No part of this work may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, without written permission from the BCPA Head Office.

We give permission for copies to be stored and made within the BCPA and any UK hospital; and these hospitals may give printed but not electronic copies to patients provided the source and copyright is acknowledged on the copies - eg include the page footer.

Authors, sources and acknowledgements

The main sources are BCPA Journal published articles, other information from authors, and publicly available documents and websites. In many cases the journal articles give sources and further information than the Glossary entries.

Parts of the wordings under ECG and Echocardiogram are adapted with permission from BUPA's health information resources, available at

We hope we have thanked everyone.

Richard Maddison

Top A B C D E F G H I J K L M N O P Q R S T U V WXYZ Copyright