Medical terms explained

Dr Rick Karsan explains some of the confusing terms that you might hear from your doctor.

Speech bubbles and question marks

Within the medical profession, there are many terms that are loosely thrown around by medical professionals and on the internet alike. 

Here are some of the most common examples of medical jargon when it comes to heart health:


This is another way of saying an abnormal heart rhythm. This is usually due to faulty conduction of electricity through the heart. There are many different types of arrhythmia which can be managed differently, including medication, a pacemaker or an ICD (an internal defibrillator). See also “heart block”.

Atrial fibrillation (AF)

This is a common abnormal heart rhythm that happens when electrical impulses fire off from different places in the atria (the top chambers of the heart) in a disorganised way. This causes the atria to twitch, and results in an irregular heartbeat or pulse. Atrial fibrillation is a major cause of stroke.

Cardiac arrest

This occurs suddenly and without warning. The most common cause of a cardiac arrest is a heart attack, but there are other causes. In cardiac arrest there is an electrical malfunction in the heart, resulting in an irregular heartbeat that disrupts the effective pumping action of the heart. As a result, the heart cannot pump blood to the brain and other organs. Death can occur within minutes if cardiopulmonary resuscitation (CPR) and defibrillation are not carried out.

Cerebrovascular accident (CVA)

This means a stroke. A stroke can occur in two forms. There can be a blockage of the blood vessels supplying the brain, and this starves the brain of blood and oxygen causing its death. This is known as an ischaemic stroke. This kind of stroke is usually caused by atherosclerosis, the same process that leads to coronary heart disease, including heart attacks. The second form is caused by the rupture of a blood vessel supplying the brain. This is known as a haemorrhagic stroke.  

Diastolic blood pressure (DBP)

This is the pressure of blood flow in the arteries as the heart relaxes and prepares for the next contraction (heart beat). It is measured in millimetres of mercury (mmHg).

Heart block

A heart block is an abnormal heart rhythm (arrhythmia) that happens when the electrical impulses that tell your heart when to beat are delayed or blocked as they travel through your heart. Some heart blocks will not cause any symptoms, but others are more serious and may need treatment such as a pacemaker.

Heart failure (HF)

Heart failure is a condition whereby the heart muscle is unable to pump blood around the heart effectively. This usually occurs because the heart muscle has become stiffened or weak. It is a long-term condition which worsens over time and requires medical management. Symptoms include shortness of breath, leg swelling and lethargy. Symptoms can develop quickly and suddenly (acute heart failure) or over a longer period of time (chronic heart failure). 


Hypertension means high blood pressure. This is clinically defined as blood pressure consistently above 140/90 mmHg. The two numbers in a blood pressure reading refer to the systolic and diastolic blood pressure respectively.

Ischaemic cardiomyopathy

Ischaemic cardiomyopathy (IC) is a condition when your heart muscle is weakened as a result of a heart attack or coronary artery disease. This can result in heart muscle damage, which leads to heart failure.

The word “ischaemic” means there is a problem with blood supply to a particular part of the body, while “cardiomyopathy” is a general term for diseases of the heart muscle.

Ischaemic heart disease (or Coronary heart disease)

This refers to the disease process, atherosclerosis, which causes narrowing of the blood vessels supplying the heart muscle. This results in impaired blood flow to the heart muscle causing symptoms including chest pain (angina) and shortness of breath. This disease process can ultimately result in a heart attack.

Myocardial infarction (MI)

This is the technical term for a heart attack. The word myocardial refers to the heart muscle or 'myocardium'. Infarction refers to a blockage in blood supply.  Most myocardial infarctions are due to atherosclerosis – a build-up of fatty and hardened plaques in the artery walls that block off the blood supply. 


This stands for “ST-elevation myocardial infarction” – in other words, it’s a type of heart attack (see also ‘myocardial infarction’). ST-elevation refers to the way that the heart attack is shown on the ECG test. Usually, it means that one of the coronary arteries supplying your heart is completely blocked.

Supraventricular tachycardia (SVT)

This is a condition where your heart suddenly beats much faster than usual. This may happen for a few minutes or a few hours. It is caused by a problem with the electrical system of your heart. It is not usually serious but can sometimes need treatment. 

Systolic blood pressure (SBP)

This is the pressure of the blood flowing through your arteries as your heart contracts and pumps blood around the body. It is measured in millimetres of mercury (mmHg).

Transient ischaemic attack (TIA)

Also known as a mini-stroke. This is a temporary loss of blood supply to the brain which can result in an episode of reversible neurological symptoms. The disease process is similar to that of an ischaemic stroke but the symptoms last minutes to hours. This tends to be a warning and the risk of a full stroke is highest within the first 48 hours. So anyone experiencing a TIA should call 999, in case it does develop into a full stroke, and also so that your future risk can be assessed in hospital.

More useful information