AF Information & Advice For Patients

AF definitions, abbreviations and frequently used terms

Understanding cardiac arrhythmias - Click here to view a short video.



Arrhythmia Alliance


Antiarrhythmic drug


A procedure to destroy or isolate the abnormal sources of electrical impulses that may be causing an arrhythmia. There are various kinds of ablation varying in invasiveness.




Automated External Defibrillator


Atrial fibrillation. May be paroxysmal (episodes which come and go), persistent, or permanent. Sometimes it is symptomatic, sometimes asymptomatic. Known as A-Fib in America.


A heart condition that occurs when the blood supply to the muscles of the heart is restricted.


A group of medications used to suppres the irregular rhythms of the heart.


A group of medications used to slow down the speed at which the blood clots, to prevent blood clots. Anticoagulants are also known as 'blood thinners' although their mechanism does not actually thin the blood.


Irregular heart rhythm


Blood vessels that carry blood away from the heart.


Cessation of heartbeat

Atrial flutter

Rapid but regular atrial rhythm disorder

Atrium (plural atria)

Top chambers of the heart that receive blood from the body and the lungs. The right atrium is where the heart's natural pacemaker (the sino-atrial node) is found.

Beta blockers

Medicine used to slow the heart rate that can be prescribed in AF patients.

Blood clot

A thickened mass in the blood formed by tiny substances called platelets.

Blood pressure

The pressure exerted by the blood against the walls of blood vessels.


Slow heart rhythm


Coronary artery disease

Cardiac arrest

When the heart stops beating

Cardiac physiologist

A staff member skilled in interpreting and providing information on your heart rhythm

Cardiac Resynchronisation Therapy (CRT)

A pacemaker implanted under the skin to help with the symptoms of heart failure and to help improve heart function.

Cardiology department

A hospital department where investigations for your heart take place


a doctor specialised in treating heart conditions


The use of a small energy shock to restore normal heart rhythm

Catheter ablation

Form of ablation using thin flexible tubes to access the heart


Scoring system used to calculate individual risk of AF-related stroke and the possible need for anticoagulation


Coronary heart disease


Secondary symptoms that occur, or procedures that are carried out, along with a main one


Cardiovascular accident (stroke)


The use of high energy shock to stop fast heart rhythms


Shortness of breath

Ectopic heartbeats

Heartbeats which occur out of turn, where the heart may be felt to 'thump'. They are common and nearly always harmless.

Event monitor

Monitor to record heartbeats


Electrocardiography, when wires are placed on the chest to monitor the heart


... or just "echo". A three-dimensional soundwave image of the heart.


Electroencephalography, when wires are placed on the head to read the electrical output of the brain


Electrophisiologist, a specialist in cardiac electrophysiology

Hand held activator

A small box allowing you to save information on your loop recorder


Score system to determine bleeding risk

Heart attack

Occurs when one of the coronary arteries becomes blocked by a blood clot. The blood supply to part of the heart muscle is blocked, causing part of the heart muscle to die. Also known as myocardial infarction.

Heart block

When electrical impulses are slowed or blocked as they travel from the top to the bottom chambers of the heart

Heart failure

A condition whereby the heart is not pumping sufficient blood for the body's needs


High blood pressure


Low blood pressure


Insertable loop recorder - A monitor implanted for a period of time to record your rhythm


Implantable Cardioverter Defibrillator


Left atrial appendage. A small pouch on the heart where clots can form. A procedure can close off (occlude) the pouch and thereby prevent clots from travelling to the brain and causing an AF-stroke.


Oral anticoagulants (sometimes known as blood thinners) which may be divided into vitamin K antagonists (e.g. warfarin) or non-vitamin K antagonists (e.g. dabigatran).


New or novel oral anticoagulants introduced in the UK since 2012


A small, sealed electrical device which is connected to you heart. A pacemaker can monitor your heart and produce electrical impulses to treat abnormal heart rhythms


Paroxysmal atrial fibrilaltion


Pulmonary vein isolation

Pulse generator

Part of the ICD which contains a battery and electric circuits

Sinus rhythm

Normal rhythm of the heart


Also known as a 'brain attack'. Has differing levels of severity and recovery. Can be caused by a clot blocking an artery (ischaemic stroke) or a bleed (haemorrhagic stroke).


Supraventricular Tachycardia - A rapid abnormal heart rhythm that begins in the upper chambers of the heart.


Loss of consciousness due to Bradycardia or asystole


Thromboembolism, where a blood clot becomes dislodged and blocks a blood vessel


Transient Ischaemic Attack. A mild stroke from which recovery may be partial or total.


Video-assisted thoracoscopic surgery - a form of keyhole surgery


The two lower chambers of the heart. The right ventricle pumps blood into the lungs and the left ventricle pumps blood around the body.

Ventricular fibrillation

A fast, dangerous heart rhythm which causes the heart to stop pumping. A shock can stop it and return the heart back to a normal rhythm. A cardiac arrest can soon follow if the rhythm is not treated quickly with a shock.


Vitamin K antagonists. A form of anticoagulants.

VT or V-Tach

Ventricular tachycardia - A fast rhythm which causes the heart to pump less efficiently, and can lead to dizziness, fainting and unconsciousness.

Get in touch for more help and information

01789 867


Send us your feedback

Patient Resources

To download our information resource and receive regular updates from AF Association please enter your details below*:

No thanks

*Please note you can unsubscribe from our mailing list at any time

This link will take you to the site

Stay on this site