Glossary of Common Heart Rhythm Terms

If you or a loved one has been diagnosed with a heart rhythm issue, you’ve likely encountered some medical terms you hadn’t heard before. This glossary of common heart rhythm terms provides a quick definition of many conditions, diagnostic tests, and treatments for heart rhythm issues.

• Ablation — Targeted removal of tissue. Often used to fix heart rhythm problems by clearing obstacles or changing the path of electrical signals.
• Angiogram — A test that uses contrast day and X-ray to observe blood flow through the heart, arteries, or veins. 
• Antiarrhythmic — A drug used to treat irregular heart rhythms.
• Anticoagulant — A drug used to thin blood.
• Arrhythmia — Irregular heartbeat.
• Atrioventricular node — Cells near the center of the heart that pick up electrical signals and pass them to the lower chambers of the heart.
• Atrium/Atria — One of the two upper chambers of the heart. The plural of atrium is atria.
• Beta blocker — A drug used to block epinephrine. Commonly known as adrenaline, this hormone raises blood pressure.
• Bradycardia — Abnormally slow heartbeat.
• Bundle branch block — A problem with the heart where the conduction system can’t conduct electricity correctly. This causes irregular heart rhythm.
• Cardiac catheterization — A procedure where a thin, hollow tube is fed through a blood vessel into the heart in order to diagnose and treat certain heart conditions.  
• Cardioversion — Applying electrical shocks to the chest to turn an irregular heartbeat to a regular heartbeat. Can also be done with medication in some cases.
• Conduction system — The fibers that carry electrical impulses through the heart.
• Cryoablation — Removal of tissue using a cold probe.
• Defibrillator — A device used to restore normal heart rhythm using an electric shock.
• Echocardiography — A way to study the heart by bouncing sound waves off the heart and recording them with an electronic sensor. Also known as an ultrasound of the heart, this diagnostic test creates a picture of the heart.
• Electrocardiogram — A test conducted with sensors placed on the body to sense electrical information related to the heartbeat. Commonly known as an ECG or EKG. 
• Electrophysiological study — A test used to study arrhythmias. The doctor uses an electrical current to stimulate the heart and force an arrhythmia to help diagnose and determine the best course of treatment. 
• Fibrillation — Uncoordinated and disordered contractions of heart fibers. A heart chamber in fibrillation cannot pump blood effectively. This can occur as atrial fibrillation (AFib) or ventricular fibrillation. 
• First-degree heart block — A slowing of the electrical signal in the upper chamber of the heart.
• Flutter — Fast and uncoordinated contractions. Not as disordered as fibrillation.
• Heart block — A delay or blockage in the electrical system in the heart.
• Holter monitor — A wearable device used to record the heart rhythm over a longer period of time than an in-office test. It’s often used to find intermittent problems that might not show up in a regular scan.
• Implantable cardioverter defibrillator — A machine that monitors heart rate and rhythm and delivers electrical energy to the heart to stabilize abnormally fast rhythms.
• Maze surgery — A surgery that uses a pattern of cuts to create new electrical pathways in the heart.
• Pacemaker — A machine that is surgically implanted in the body to help regulate the heartbeat. 
• Palpitation — The feeling caused by irregular heartbeats.
• Premature ventricular contraction — A contraction in the lower chambers of the heart that’s out of sync with the rest of the heart. The contract may occur too soon or may simply be an extra contraction.
• Second-degree heart block — A delay in the heart’s electrical signals between the upper and lower chambers.
• Sick sinus syndrome — A disease caused by the heart’s sinus node failing to properly regulate rhythm.
• Sinus node — The cluster of cells that produces electrical impulses that travel through the heart to keep it in time.
• Stokes-Adams disease — A condition that occurs when the electrical impulses in the top half of the heart can’t reach the bottom, which typically leads to fainting spells. 
• Syncope — Loss of consciousness caused by lack of blood flow to the brain. Often caused by arrhythmia.
• Tachycardia — Abnormally fast heartbeat.
• Transesophageal echocardiography — A test that bounces sound waves off the heart by means of a tube inserted down the throat.
• Ventricle — One of the two lower chambers of the heart.
• Wolff-Parkinson-White syndrome — A disease caused by an extra electrical pathway connecting the upper and lower chambers of the heart.

If you have any questions about a heart rhythm issue or related treatment, we encourage you to call the Oklahoma Heart Hospital’s Heart Rhythm Institute to speak to your physician or schedule an appointment with one of our specialists.