Atrial Fibrillation
 RESOURCES FOR PATIENTS

GLOSSARY

A-Fib:

Abbreviation for Atrial Fibrillation

Ablation:

The removal of heart tissue which causes A-Fib. This tissue is physically destroyed by applications of RF, laser or ultrasound energy.

Adrenergic A-Fib:

See Vagal A-Fib.

AF:

Abbreviation for Atrial Fibrillation

AFib:

Abbreviation for Atrial Fibrillation

Amiodarone:

Brand name Cordarone. An antiarrhythmic drug (Class 3). See Medications.

Aneurysm:

A ballooning out of a blood vessel or of a portion of the heart muscle. If the aneurysm ruptures, it can be deadly.

Angina Pectoris:

Chest pain caused by reduced blood flow to the heart.

Antiarrhythmic Medications:

Drug therapy that attempts to stop A-Fib and make the heart beat normally. See Medications.

Anticoagulants:

Medications such as aspirin (Plavix, Ticlid) and warfarin (Coumadin) which thin the blood helping to prevent blood clots and stroke. See Medications.

Arrhythmic:

Having an abnormal heart beat (too fast [Tachycardia], too slow [Bradycardia] or irregular [Fibrillation]).

Atrial Fibrillation (A-Fib):

A heart rhythm disorder in which the upper chambers of the heart (the atria) contract (quiver) very rapidly and irregularly as many as 300-600 times a minute, due to chaotic, uncoordinated electrical activity.

Atrial Flutter:

A heart rhythm disorder in which the upper chambers of the heart (the atria) contract faster than the lower chambers (the ventricles) in an organized, predictable pattern. (In Atrial Fibrillation the atria beat chaotically and irregularly.)

Atrio-Esophageal Fistula

A hole that forms between the atrium and the esophagus, often resulting in death. It is presumably caused by the use of high wattage catheters during catheter ablation procedures to cure A-Fib.

Atrioventricular (AV) Node:

The AV Node is specialized conducting tissue that acts as an electrical road or gate connecting the atria to the ventricles. Normally the AV Node is the only electrical connection between these heart chambers. See Overview.

Atrioventricular (AV) Nodal Reentry Tachycardia (AVNRT):

The AV Node develops two pathways instead of one, allowing a signal to go down one pathway, then back up the other pathway to the atrium (reentrant circuit) resulting in Supraventricular Tachycardia (speeding up the heart beat).

Atrium (plural Atria):

Either one of the two upper chambers of the heart in which blood collects before being pumped into the lower chambers (ventricles). See Overview.

AV Node:

See Atrioventricular Node.

AVNRT:

See Atrioventricular (AV) Nodal Reentry Tachycardia.

Beta Blocker:

A medication that slows down conduction through the heart and makes the AV Node less sensitive to A-Fib impulses. See Medications.

Betapace:

See Sotalol.

Bradycardia:

A heart rhythm problem in which the heart beats slower than normal. Bradycardia may be caused by the SA Node not working properly or by the electrical pathway in the heart being blocked (heart block).

Calcium Channel Blocker:

A medication that prevents or slows the flow of calcium ions into smooth muscle cells such as the heart. This impedes muscle cell contraction, thereby allowing blood vessels to expand and carry more blood and oxygen to tissues. See Medications.

Cardiac Arrest:

When the heart quits pumping effectively.

Cardiologist:

A doctor who specializes in the diagnosis and treatment of heart disease.

Cardiomyopathy:

A heart condition or disease in which the heart muscle is weakened and the heart's ability to pump blood is impaired. It is often accompanied by atrial fibrillation.
    - Dilated Cardiomyopathy: The lower chambers of the heart become enlarged and cannot pump efficiently.
    - Hypertrophic Cardiomyopathy: The walls of the heart become thickened and stiff, and are unable to properly fill and pump blood efficiently. This disorder often runs in families.
    - Restrictive Cardiomyopathy: The heart chambers are unable to expand and fill with blood between contractions.
(See http://www.hrspatients.org/patients/the_normal_heart/
structural_defects.asp)

Cardioversion:

Converting the heart from A-Fib to normal rhythm by using medications and/or electrical shock.
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CARTO Mapping:

An A-Fib mapping system that uses a special catheter to generate 3-D maps of the heart.

Catheter:

A soft, thin, flexible tube with an electrode at the tip.

Catheter Ablation:

A procedure in which a catheter (a soft, thin, flexible tube with an electrode at the end) is inserted through a vein or artery in the groin or neck and moved into the heart. Through the electrode, RF, laser, Cryo (freezing) or ultrasound energy is applied to eliminate or physically destroy specific heart tissue.

CAT Scan:

Short for Computed Axial Tomography---a method of producing 3-D images by recording the passage of waves of energy through structures.

Caviotricuspid Isthmus:

In the Right Atrium this is the space between the Inferior Vena Cava and the Tricuspid Valve. In ablation for Right Atrial Flutter, a Caviotricuspid Isthmus ablation line is often made to prevent Atrial Flutter.

Chronic Atrial Fibrillation:

In chronic A-Fib the heart remains in A-Fib all the time, as contrasted with "paroxysmal" A-Fib where the heart has occasional attacks of A-Fib.

Circumferential Catheter Ablation:

A Catheter Ablation technique that utilizes a circular catheter to make circular lesions around the Pulmonary Vein openings, thereby isolating the Pulmonary Veins from the rest of the heart. This prevents A-Fib pulses produced in the Pulmonary Veins from spreading through the rest of the heart. A type of Pulmonary Vein Ablation.

Class 1 Medications:

Sodium Channel Blocker medications which decrease the speed of electrical conduction in the heart muscle. See Medications.

Class 2 Medications:

Beta-Adrenergic or Beta-Blocker medications which slow down conduction through the heart and make the AV Node less sensitive to A-Fib impulses. See Medications.

Class 3 Medications:

Potassium Channel Blockers which slow nerve impulses in the heart. See Medications.

Class 4 Medications:

Calcium Channel Blockers which prevent or slow the flow of calcium ions into smooth muscle cells such as the heart. This calcium blocking impedes muscle cell contraction, thereby allowing blood vessels to expand and carry more blood and oxygen to tissues. See Medications.

Complex Fractionated Atrial Electrograms:

A low voltage A-Fib signal with many deflections and irregular spiking and often with a very short cycle length. Discovered by Dr. Nademanee they are used to identify sources of A-Fib in the heart.

Congestive Heart Failure:

The heart is unable to pump adequate amounts of blood, often as a result of a heart attack.

Cordarone:

Coronary Artery Disease (CAD):

Plaque accumulates in  the coronary arteries limiting  the flow of blood to the heart. CAD sometimes results in a blood clot that causes a heart attack.

See Amiodarone.

Coumadin:

An anticoagulant whose generic name is "Warfarin." See Medications.

C-Reactive Protein (CRP):

A marker or sign of inflammation, often found in patients with A-Fib.⁸²

Cryoablation:

An ablation technique that freezes the focal sources of A-Fib rather than ablating them with RF energy. Currently still in the experimental and trial stages for A-Fib.

Defibrillator:

An electrical device that delivers a shock in order to restore the heart to normal rhythm. It is used primarily in life threatening conditions to stop very rapid and irregular heart beats.

Diastolic Blood Pressure:

The optimal blood pressure reading currently is 115/75.⁵⁹ The "75", the second number, is the Diastolic Blood Pressure---the amount of pressure in your arteries when your heart is at rest between beats. See Systolic Blood Pressure.

Digoxin:

A rate-control medication that is a Digitalis compound, brand name Lanoxin. Digoxin slows down and controls the heart rate by blocking the electrical conduction between the atria and ventricles. See Medications.

Ditiazem:

A rate-control calcium-channel blocker medication. See Medications.

Disopyramide:

Brand name Norpace. An antiarrhythmic drug (Class 1A). See Medications.

Dofetilide:

Brand name Tikosyn. An antiarrhythmic drug (Class 3). See Medications.
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ECG:

See Electrocardiogram.

Ectopic Beats:

Beats that come from any region of the heart that ordinarily should not produce heart beat signals. Normal heart beats come from the Sinus Node, not from areas like the Pulmonary Vein openings where most A-Fib signals originate. See Overview.

Effective Refractory Period (ERP):

    Effective Refractory Period (ERP) refers to the period of time a cell can not be activated by a new action potential. The ERP acts as a protective mechanism in the heart by preventing multiple, compounded action potentials from occurring (i.e., it limits the frequency of depolarization and therefore heart rate). This is important because at very high heart rates, the heart would be unable to adequately fill with blood and therefore ventricular ejection would be reduced.
    Many antiarrhythmic drugs alter the ERP, thereby altering cellular excitability. For example, drugs that block potassium channels (e.g., amiodarone, a Class III antiarrhythmic) delay phase 3 repolarization and increases the ERP. Drugs that increase the ERP can be particularly effective in abolishing reentry currents that lead to arrhythmias. [Based on "Cardiovascular Physiology Concepts by Richard E. Klabunde.]¹⁰³

Ejection Fraction:

The ratio of the volume of blood the heart pumps out during contraction to the volume of blood in the heart when it fills up with blood. It is expressed as a percentage normally between 56 and 78 percent.

EKG:

See Electrocardiogram.

Electrical Cardioversion:

Delivering an electrical shock to the heart in order to convert it from A-Fib to normal rhythm.

Electrogram (EGM):

A picture of the electrical activity of the heart as sensed by an ICD or pacemaker implanted in the heart. (This is different from an Electrocardiogram which senses the heart's electrical activity from the surface of the skin.)

Electrocardiogram (ECG or EKG):

A graphical representation of the electrical activity of the heart. 12 sensors placed on different parts of the body record electrical activity from 12 different areas of the heart. These signals are listed as I, II III, aVR, aVL, aVF, V1, V2, V3, V4, V5, V6. An Electrocardiogram is used as an examination tool to determine if you have A-Fib, and can show a doctor where in your heart an arrhythmia signal is coming from. It is also used during an ablation procedure to determine if an A-Fib signal source has been ablated/isolated.

Electrophysiologist:

A Cardiologist who specializes in the electrical activity of the heart and in the diagnosis and treatment of heart rhythm disorders. (It is usually an Electrophysiologist who performs Pulmonary Vein Ablations.)

Electrophysiology Study (EP) (EPS):

A test which uses a catheter inserted through the veins into the heart to determine which areas in the atria give rise to Atrial Fibrillation or Flutter.

Esmolol:

A rate control beta-blocker medication. See Medications.

Esophageal Fistula

A hole that forms in the esophagus. See Atrio-Esophageal Fistula.

Event (Loop) Recorder:

A patient-triggered monitor/recorder. When you feel an episode of A-Fib, you press a button to record several minutes of the A-Fib episode.

Fibrillation:

Rapid, uncoordinated contractions of individual heart muscle fibers.

Flecainide:

Brand name Tambocor. An antiarrhythmic drug (Class 1C). See Medications.

Fluoroscopy:

A special type of x-ray that allows the heart to be visualized.

Flutter:

Rapid contractions of individual heart muscle fibers.

Focal Circuit:

A-Fib coming from a particular spot in the heart. (See also Reentrant Circuit.)

Focal Point Catheter Ablation:

A procedure in which a catheter (a soft, thin, flexible tube with an electrode at the tip) is inserted through a vein or artery in the groin or neck and moved into the heart. This catheter is directed to the exact point(s) in the heart that are producing the A-Fib. These points are burned off or isolated from the heart. See Focal Point Catheter Ablation.

Heart Attack (Myocardial Infarction):

A total blockage of blood flow to a portion of the heart. This damages the heart's muscle cells.

Holter Monitor:

A small, portable monitor that continually records the heart's rhythm for 24-72 hours.

Hypertension:

High blood pressure.

Hypertrophic Cardiomyopathy:
See Cardiomyopathy.

Ibutilide:

An antiarrhythmic drug (Class 3). See Medications.

ICD:

Abbreviation for Implantable (Cardioverter) Defibrillator

ICE:

Short for Intracardiac Ultrasound (Echo) which uses Ultrasound to image within the heart in real time.

Implantable (Cardioverter) Defibrillator [ICD]:

An implanted electronic device which delivers a shock to the heart any time it senses the heart going into A-Fib. See Implanted Defibrillator.

INR (International Normalized Ratio):

A measurement of the amount of blood thinner in the blood stream. To be effective warfarin must be maintained at a certain level in the blood (INR---International Normalized Ratio between 2.0 and 3.0). Above 4.0 you run the risk of having a hemorrhagic (bleeding) stroke. Below 2.0 you are more in danger of having an ischemic (clotting) stroke, the kind that most often occurs in A-Fib

Intracardiac Ultrasound (Echo) (ICE):

Using Ultrasound to image within the heart in real time.
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Isolation:

A catheter ablation technique that creates lesions (cuts or scars) around a source of A-Fib to keep it from transmitting A-Fib signals into the rest of the heart. If a source of A-Fib area is "isolated," it is still producing A-Fib signals, but they aren't spreading to the rest of the heart. See Focal Point Catheter Ablation.

Isoproterenol:

A drug used to stimulate the heart into A-Fib during a Pulmonary Vein Ablation procedure.

Left Atrial Appendage:

Most strokes come from the Left Atrial Appendage (91%)⁸⁷ which is located at  the top of the Left Atrium. It is a very complicated structure with often more than one lobe. In A-Fib the flow of blood from the Left Atrial Appendage is particularly poor. Clots can easily form. Then when the heart beats, these clots can dislodge and cause stroke.

Lesions:

In Focal Point Catheter Ablation of A-Fib, lesions are electronically created cuts or scars.

Lone (Idiopathic) Atrial Fibrillation:

A-Fib without any accompanying or triggering heart disease or other illness.

Loop (Event) Recorder:

A patient-triggered monitor/recorder. When you feel an episode of A-Fib, you press a button to record several minutes of an A-Fib episode.

Maze Surgical Operation:

An open heart operation in which the surgeon makes numerous incisions in the atria. This "maze" of incisions divides the atria into electronically isolated segments, thereby blocking the electrical impulses that cause A-Fib from spreading throughout the heart. The atria continue to be activated by a regular signal from the Sinus Node. See Maze Surgical Operation.

Metoprolol:

A rate control beta-blocker medication. See Medications.

Myocardial Infarction:

The medical term for a Heart Attack. See Heart Attack.

Normal Heart Rhythm (also called "Sinus Rhythm"):

The normal beating of the heart (60-80 beats per minute). See Overview.

Norpace:

See Disopyramide.

Ostium (plural Ostia):

The opening from a pulmonary vein into the left atrium.

PAC:

Abbreviation for Premature Atrial Contraction. A common and generally benign arrhythmia that occurs even in people with normal heart rhythm. A PAC is a heartbeat that comes from some other area than the sinus node. It feels like a skipped or extra heart beat.

Pacemaker:

A small, implantable device that provides an electrical stimulus to the heart when the natural electrical signal is absent or too slow to provide sufficient pumping action.

Paroxysmal Atrial Fibrillation:

Occasional attacks of A-Fib, as contrasted with "chronic" A-Fib where the heart remains in A-Fib all the time.

Pericarditis:

Inflammation of the pericardium, the sac that surrounds your heart.

Persistent Atrial Fibrillation:

A-Fib that lasts over 24 hours but that is amenable to cardioversion.

Polar Heart Rate Monitor:

A device for monitoring your heart rate in A-Fib. Designed primarily for runners it consists of a band around your chest which transmits a signal to a wrist watch. You can set the wrist watch to set off an alarm if your pulse rate goes too high. Available in sporting goods stores.

Premature Atrial Contraction (PAC):

A common and generally benign arrhythmia that occurs even in people with normal heart rhythm. A PAC is a heartbeat that comes from some other area than the sinus node. It feels like a skipped or extra heart beat.

Proarrhythmic:

A medication is "proarrhythmic" if it worsens your heart rhythm rather than making it more regular.

Procainamide:

Brand names Procan SR, Promine, Pronestyl, Procanbid. An Antiarrhythmic drug (Class 1C). See Medications.

Procan SR:

See Procainamide.

 Procanbid:

See Procainamide.

Promine:

See Procainamide.

Pronestyl:

See Procainamide.
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Propafenone:

Brand name Rythmol. An antiarrhythmic drug (Class 1C). See Medications.

Propranolol:

A rate control beta-blocker medication. See Medications.

Pulmonary Vein:

The four Pulmonary Veins bring oxygenated blood from the lungs into the left atrium. (The openings from these Pulmonary Veins into the left atrium are the source of most Focal Point A-Fib).

Pulmonary Vein Ablation:

A term used to refer to both Segmental and Circumferential Catheter Ablation. It is replacing the term "Focal" or "Focal Point Catheter Ablation."

Pulmonary Vein (PV) Potentials:

An electrical charge or energy (potential) in the Pulmonary Vein openings that can cause A-Fib. A PV Potential can be measured and pinpointed even if you aren't in A-Fib at the time. See Focal Point Catheter Ablation.

PV Stenosis:

Swelling of the Pulmonary Vein opening that may occur after Catheter Ablation. This swelling can restrict blood flow from the lungs into the heart. See Questions For Doctors.

Quinaglute:

See Quinidine.

Quinidex:

See Quinidine.

Quinidine:

Brand names Quiniglute, Quinidex, Quinidine Glaconate. An antiarrhythmic (Class 1A) drug. See Medications.

Quinidine Glaconate:

See Quinidine.

Radio Frequency (RF):

High frequency electrical energy used in Catheter Ablation.

Rate Control Medications:

Drug therapy that attempts to control your heart rate (ventricular beats), but leave the upper chambers (atria) of your heart in A-Fib. See Medications.

 Reentrant Circuit (Macro Reentrant Circuit):

Circular, random electrical patterns or wavelets found in the Atria of patients with A-Fib and A-Flutter.

Remodeling:

In A-Fib over a period of time, the fast, abnormal heart rhythm in the atria causes electrical changes and enlarges the atria.

Rythmol:

See Propafenone.

Segmental Catheter Ablation:

A Catheter Ablation technique that uses Pulmonary Vein Potentials to identify and ablate (destroy) focal points or areas of the heart producing A-Fib signals. A type of Pulmonary Vein Ablation.

Sinoatrial (SA) Node:

See Sinus Node.

Sinus Node:

(Also called "Sinoatrial [SA] Node.") The Sinus Node is a specialized group of cells in the heart which generates an electrical signal that travels down a single electrical road (the AV Node) connecting the atria to the ventricles. The Sinus Node is called the heart's "natural pacemaker," because it maintains a regular heart beat and makes adjustments to increase the heart rate during exercise and to slow it during rest. See Overview.

Sinus Rhythm:

The normal beating of the heart (60-80 beats per minute). Also called "Normal Heart Rhythm." See Overview.
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Sotalol:

Brand name Betapace. A rate control beta-blocker medication. (Class 3 drug.) See Medications.

Spline:

A spline has a series of projections on a shaft that fit into slots on a corresponding shaft. A spline is used on a catheter to insert the Watchman device.

Stenosis:

A swelling, constriction or narrowing of a duct or passage. See PV Stenosis.

Structural Heart Disease:

This term can refer to several different structural defects in the heart:
    1. Heart muscle disease (Cardiomyopathy)
    2. Heart valve disease
    3. Congenital heart disease (patients born with abnormalities of the heart valves or chambers)
    4. Heart damage caused by infection, such as Paricarditis

Supraventricular Tachycardia (SVT):

An arrhythmia similar to A-Fib in which the heart beats fast (100 to 240 beats per minute). SVT usually begins and ends suddenly. SVT often begins in childhood or adolescence. It is commonly caused by a variation in the electrical system of the heart. It is usually not dangerous, but can cause a drop in blood pressure and lightheadedness.

SVT:

See Supraventricular Tachycardia.

Systolic Blood Pressure:

The optimal blood pressure reading currently is 115/75.⁵⁹ The "115", the first number, is the Systolic Blood Pressure---the pressure your heart generates when pumping blood through your arteries. See Diastolic Blood Pressure.

Tachycardia:

A heart rhythm problem in which the heart beats faster than normal.

TEE:

See Transesophageal Echocardiogram

Tambocor:

See Flecainide.

Tikosyn:

TIA:

Transient Ischemic Attack, a temporary "mini-stroke"

See Dofetilide.

Toprol-XL:

A rate control beta-blocker medication.  See Medications.

Transmurality:

Passing through the wall of the heart or involving the whole thickness of the heart wall.

Transesophageal Echocardiogram:

In this procedure used to test for the presence of blood clots in the heart, a tube is run down your Esophagus next to your heart. The Echocardiogram uses ultrasonic waves to visualize structural and functional abnormalities of the heart.

Ultrasound:

High-frequency sound vibrations used in some types of Catheter Ablation.

Vagal A-Fib:

The Adrenal (Adrenergic) Glands sit above the kidneys and produce the hormone epinephrine (adrenaline) in response to stress, which causes an increase in heart rate and blood pressure. This adrenaline stimulates what is called the Sympathetic Nervous System to speed up the heart and constrict the blood vessels. The Vagus Nerve, in contrast, controls the abdomen and is part of the Parasympathetic Nervous System that tends to slow the heart and dilate blood vessels.
    Adrenergic and Vagotonic forms of paroxysmal A-Fib are uncommon.⁴³ "The majority of patients with paroxysmal A-Fib do not have a clear autonomic pattern."¹¹⁰ However, if your A-Fib is normally triggered by exercise, stress, stimulants, exertion, etc., then you may have "Adrenergically-Mediated" A-Fib. People with structural heart disease seem more prone to Adrenergic A-Fib⁴⁴. But if your A-Fib occurs at night, after a meal, when resting after exercising, or when you have digestive problems, then you may have "Vagally-Mediated" A-Fib. People with Lone A-Fib seem more prone to Vagal A-Fib⁴⁴. (Many people have a mix of both Adrenergic and Vagal A-Fib.) (Perhaps A-Fib begins as a nervous system problem, then becomes a heart problem after the arrhythmia is established.)
    It might be helpful to determine if you have one or the other so that you can better identify what triggers your A-Fib, and because the treatments are often different for each. For example, beta-blockers usually don't work well with Vagal A-Fib.⁸⁶ Of the antiarrhythmic 1c meds, flecainide seems to work better for Vagal A-Fib than propafenone.¹¹¹ (Though it's difficult to generalize about A-Fib treatments, because each person reacts so individually.) For a more in depth look at Vagal A-Fib, go to http://www.vagalafibinfo.fsnet.co.uk (This site seems to have disappeared from the Internet as of October, 2006).
    See also in the FAQs section "What is the difference between "Adrenergic" and "Vagal" Atrial Fibrillation. How can I tell which one I have? Does it really matter? Does Pulmonary Vein Ablation (Isolation) work for Adrenergic and/or Vagal A-Fib?"

Ventricles:

The lower chambers of the heart. See Overview.

Verapamil:

A rate control calcium-channel blocker medication. See Medications.

Vitamin K Antagonist (VKA):

A technical description of how VKAs work is the following: "they prevent the y-carboxylation of the vitamin K-dependent coagulation factor prothrombin and Factors VII, IX, and X."¹¹⁵ In layman’s terms warfarin works by affecting several steps in the anticoagulation pathway to prevent clotting.

VKA:

See Vitamin K Antagonist

Warfarin:

The generic name of an anticoagulant whose product name is "Coumadine." See Medications.

Watchman Device:

See Watchman device.

Wolff-Parkinson-White syndrome (WPW):

A form of Supraventricular Tachycardia, WPW occurs when electrical signals fail to pause in the AV Node because an extra pathway allows the impulse to "bypass" the normal pathway. Patients with WPW may develop A-Fib and are at increased risk of developing a dangerous ventricular arrhythmia.

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