A brief glossary to help you understand cardiology terms.
Ablation - Obliteration with high frequency current of heart structures which disturb electrical activity.
Antiarhythmic drug - A drug for treatment of the disturbance in cardiac rhythm.
Arrhythmia - An irregular heartbeat. A heart rhythm that is too slow is called bradycardia. A heart rhythm that is too fast is called tachycardia.
Atrial fibrillation - Uncoordinated activity of the atria, with frequencies of over 300 beats per minute
Atrium - The two upper chambers of the heart. These are called the left and the right atrium.
AV Node - The area within the heart’s electrical system that conducts electrical signals received for the atria to the ventricles.
Bradycardia - A type of heart condition in which the heartbeats abnormally slow at less than 60 beats per minute. This may be too slow or irregular to meet the body’s demands.
Cardiac Arrest - is when the heart stops pumping after an abnormally fast heart rhythm. A person loses consciousness and emergency treatment such as external defibrillation may return the heart to a more normal rhythm.
Cardiac resynchronization - Therapy that provides electrical impulses to the heart, allowing it beat in a more coordinated fashion.
CardioPulmonary Resuscitation - CPR. An emergency lifesaving procedure that is done when someone's breathing or heartbeat has stopped. (see The BHF video to learn how to do this)
Defibrillation - Removal of life threatening disturbances in cardiac rhythm (ventricular fibrillation) with an electric shock.
ECG - Electrocardiogram, a test to record the rhythm and activity of the heart
Ejection Fraction - is a measurement used by physicians to determine how well your heart is functioning. An EF is a percentage of blood that is pumped out of the heart during each beat. Also known as the left ventricular ejection fraction (LVEF)/p>
Endocardial lead - A pacing lead threaded through a vein and placed inside the heart. Also called a transvenous lead.
Epicardial lead - A pacing lead attached to the outside surface of the heart. May also be called a myocardial lead.
Heart failure - A condition in which the heart can’t pump enough blood to meet the needs of the body. Symptoms may include shortage of breath and tiredness with daily activities.
ICD - An Implantable Cardioverter Defibrillator. A medical device that monitors the heart rate and the regularity of the heart beat. It also intervenes as appropriate to control arrhythmia’s as gently as possible. If the tachycardia cannot be brought to an end by repeated stimulation, the iCD emits a single intense current impulse, the so called electric shock.
Myocardial Infarction - When the blood supply to the heart muscle is reduced, it causes part of it to die. This is commonly known as a “heart attack”.
Pacemaker - An implanted medical device that stimulates the heart muscle with precisely timed discharger of electricity. These very small amounts of electricity cause the heart to mimic a naturally occurring heart rhythm.
Pacing lead - A flexible, insulated wire. It is part of a pacing system. A pacing lead delivers the pacemaker’s electrical pulse to the heart. The lead may also relay information about the heart’s natural activity back to the pacemaker.
SA Node - The SA node is the heart’s natural pacemaker. It is located in the upper right chamber (right atrium). A properly working SA node produces small electrical impulses that vary in rate. The rate depends upon the body’s demands for oxygen.
Syncope - A short loss of consciousness.
Tachycardia - Heart rate of more than 100 beats per minute.
Ventricles - The two lower chambers of the the human heart. These are called the left and the right ventricles.
Ventricular flutter - Ventricular frequency of more than 250 beats per minute
Ventricular fibrillation - Ventricular frequency of more than 300 beats per minute, with irregular and coordinated electrical excitation of the ventricles, connected with cardiac arrest.
Ventricular tachycardia - Ventricular frequency of more than 100 beats per minute.