.

A-Fib:

Abbreviation for Atrial Fibrillation

Ablation:

The elimination of heart tissue which causes A-Fib. This tissue is physically destroyed by applications of RF, Cryo (freezing), laser, or ultrasound energy.

ACT:

Abbreviation of "Activated Coagulation Time." Used to measure the effect of high dose heparin before, during and shortly after surgeries which requires intense anticoagulation. ACT is measured at intervals during a Pulmonary Vein Ablation procedure to achieve and maintain a steady level of heparin anticoagulation. ACT is measured in seconds. The higher it is, the higher the degree of clotting inhibition.

Action Potential:

When a heart cell goes from a negative resting value to a positive value. See http://library.thinkquest.org/C003758/Function/The Cardiac Action Potential.htm

Adrenergic A-Fib:

See Vagal & Adrenergic A-Fib.

AF:

Abbreviation for Atrial Fibrillation

AFib:

Abbreviation for Atrial Fibrillation

Amiodarone:

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

Anatomically-Based Circumferential Ablation:

A type or method of Pulmonary Vein Ablation (Isolation) developed by Dr. Carlo Pappone. Also called "Left Atrial Ablation." It creates blocking lesions in the left atrium similar to "Circumferential" ablation. But instead of trying to make continuous, perfect linear lesions around the Pulmonary Veins, a large diameter catheter at a high wattage is dropped and dragged to make the circular linear lesions. There may be gaps left in these lesions which may result in Atrial Flutter. But over time scar tissue usually closes these gaps (see Morady and Pappone).
    (Please be advised that the "Anatomically Based Circumferential Ablation" procedure may be responsible for isolated cases of Atrial Esophageal Fistula in which a hole 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 fix A-Fib. If your doctor uses this procedure, ask him what steps he/she takes to prevent causing a hole to form in the esophagus.)

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 warfarin (Coumadin) which help prevent blood clots and stroke. An anticoagulant works by slowing the production of blood clotting proteins made in the liver. (Oral anticoagulants like warfarin are also called "vitamin K antagonists," since they work by counteracting the coagulation vitamin K.)

Antiplatelets:

Medications such as Aspirin, Plavix, Ticlid which help prevent blood clots and stroke. An antiplatelet works by decreasing the stickiness of circulating platelets (small blood cells that start the normal clotting process), so that they adhere to each other less and are less likely to form blood clots. (Plavix and Ticlid are antiplatelet drugs like aspirin but they are not the same or interchangeable with aspirin. If your doctor prescribes Plavix or Ticlid, you should not substitute aspirin for them.)

Aortic Valve:

The heart valve between the Left Ventricle and the Aorta. The Left Ventricle pumps oxygenated blood through the tricuspid (three flapped) Aortic Valve into the Aorta which carries it to the rest of the body. When pressure in the Left Ventricle drops, the pressure of blood in the Aorta will push the Aortic Valve closed. To see an excellent video of how this valve works, go to http://www.youtube.com/watch?v=WXwYYsi6z7Q&feature=player_embedded    

Arrhythmia:

An abnormal heart rhythm.

Arrhythmic:

Having an abnormal heart beat: too fast is called Tachycardia, too slow is called Bradycardia, or irregular is called Fibrillation.

ATP (Adenosine Triphosphate):

A chemical used by cells as an energy carrier. It transports chemical energy within cells for metabolism. See http://en.wikipedia.org/wiki/Adenosine_triphosphate

Atrial-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.

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; it usually originates in the left atrium.

Atrial Flutter (A-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.)
You can consider Atrial Flutter as a more regular variety of A-Fib. A-Flutter often, though not always, originates in the right atrium, whereas A-Fib usually comes from the left atrium.  
Here is an EKG of Atrial Flutter:
 

ECG 3 - atrial flutter

This ECG illustrated a heart in atrial flutter. This has very distinct appearance. The "flutter waves" that we expect to see in atrial flutter are noticeable throughout the ECG, but are very easy to see in the rhythm strip. The rhythm is still regular, although this is not always the case in AFL ^{130 (from wolfminimaze.com)}
 

Atrial Natriuretic Peptide (ANP):

A powerful vasodilator and a hormone secreted by heart muscle cells in the upper chambers (atria) of the heart. It reduces the water and sodium loads on the circulatory system. It is released in response to atrial stretch and other signals such as atrial fibrillation. http://en.wikipedia.org/wiki/Atrial_natriuretic_peptide

Atrial Tachycardia:

A rhythm disturbance in the atria of the heart. An electrical impulse comes from somewhere in the atria other than from the SA Node which is the normal pacemaker of the heart.
    In A-Fib Ablation, Atrial Tachycardia can be considered a milder form of Atrial Flutter. During an ablation procedure, first A-Fib signals disappear, second A-Flutter signals, then Atrial Tachycardia.

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.

Bicuspid Valve:

See Mitral Valve.

Bidirectional Block:

Refers to both Exit Block and Entrance Block, goals of a successful A-Fib ablation. Signals from both inside and outside the Pulmonary Vein can not cross the ablation lesions. 

Blood Thinners:

Antithrombotic medications which don't actually thin the blood. Rather they inhibit the ability of substances in blood to form clots.

BMBS (MBCHB, MBBS):

Bachelor of Medicine, Bachelor of Science. Awarded on graduation from medical school in various countries which follow the tradition of the United Kingdom. (Like an MD.)

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 and blood vessel problems; often referred to as the "plumber" of the heart.

Cardiomyopathy:

A heart condition or disease in which the heart muscle is weakened and the heart's ability to pump blood is impaired. For example, fibrous tissue may partially replace the heart muscle, disabling the heart so that it no longer functions properly, and blood no longer moves efficiently. Cardiomyopathy 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)
    (The World Health Organization recognizes Cardiomyopathy as a "selenium deficiency.")¹³⁴

Cardiopulmonary Bypass:

A technique that temporarily takes over the functions of the heart and lungs during heart surgery, maintaining the circulation of blood and the oxygen content of the body; commonly referred to as a heart-lung machine.  

Cardioversion:

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

Carotid Sinus Stimulus (Massage):

Doctors partially block or slow down the flow of blood through the carotid sinus. It is used to tell the difference between different types of arrhythmias, and "rarely, may also terminate the arrhythmias and reestablish sinus rhythm."²¹²

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.

CCDS:

Certified Cardiac Device Specialist. Designates an EP who has passed an exam for cardiac devices such as pacemakers. The exam is given by the International Board of Heart Rhythm Examiners (IBHRE) affiliated with the Heart Rhythm Society. This credential may not be totally relevant to A-Fib ablation.

CFAE:

Complex Fractionated Atrial Electrograms (an electrogram is a picture of the electrical activity of the heart as sensed by a pacemaker or catheter in the heart). Discovered by Dr. Koonlawee Nademanee of the Pacific Rim EP Research Institute in Inglewood, CA, they are low voltage electrical signals with very short cycle lengths used to identify areas in the heart that need to be ablated. See Complex Fractionated Atrial Electograms.

CHADS2:

CHADS2 refers to risk factors for stroke. If you have one of the risk factors, you have a risk score of 1. However, if you’ve had a stroke already, that counts as a risk score of 2 ("S2"):

• "C" Congestive Heart Failure   Score = 1
• "H" Hypertension                    Score = 1
• "A" Age 75 or over                  Score = 1
• "D" Diabetes                          Score = 1
• "S2" Previous Stroke or TIA      Score = 2

    For example, someone with a risk factor of 1 not receiving any anticoagulant therapy would have 1.9%-2.8% chance of having a stroke within a year, whereas someone with a score of 6 would have an 18.2% chance of having a stroke.

CHA2DS2-VASc:

A European refinement of the CHADS2 identifying more risk factors for stroke.
    • "C" Congestive Heart Failure/     Score = 1
        LV Dysfunction
    • "H" Hypertension                        Score = 1
    • "A2" Age 75 or over                    Score = 2
    • "S2" Stroke/TIA                          Score = 2
    • "V" Vascular Disease (prior
        heart attack, peripheral
        artery disease, aortic plaque)    Score = 1
    • "A" Age 65-74                             Score = 1
    • "Sc" Sex category (female)          Score = 1
    People with a score of 1 can be treated with aspirin or oral anticoagulant, but preferably oral anticoagulant. People with a score of 2 or above should be treated with oral anticoagulant. Low risk people with a score of 0 don't need blood thinners.
    This risk factor model recognizes that women have a significant risk of stroke. Any woman 65 or over should be on anticoagulants. 

 

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 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 (CFAEs):

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. See CFAEs.

Congestive Heart Failure:

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

Cordarone:

See Amiodarone.

Coronary Artery Desease (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.

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.

Dabigatran (brand name Pradaxa):

Dabigatran is a direct thrombin inhibitor, a newer type of blood thinner medication. Thrombin is an enzyme that converts soluble fibrinogen into insoluble fibrin. Fibrin is a fibrous protein involved in the clotting of blood. It forms a mesh or clot over a wound. Dabigatran does not require close monitoring and has less bad side effects than warfarin. It is expected to replace warfarin as the blood thinner of choice 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.

DHA:

Docosahexaenoic Acid, a fish oil/omega-3 fatty acid that plays a crucial role in brain function, as well as in normal growth and development.

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.

DO:

Doctor of Osteopathic Medicine

Dofetilide:

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

See Electrocardiogram.

Echocardiography (Cardiac Ultrasound):

An imaging technology in which special sound waves are bounced off of the structures of the heart. A computer converts these images into moving pictures. 

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, or produced by catheter mapping devices inside 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 sometimes 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; the "electrician" of the heart.  (An Electrophysiologist 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.

Entrance Block:

When a signal can not enter a pulmonary vein isolated by catheter ablation lesions. This is a goal of a successful A-Fib ablation, along with Exit Block. Entrance and Exit Block are called Bidirectional Block. 

EPA:

Eicosapentaenoic Acid, a fish oil/omega 3 essential fatty acid

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 portable type of EKG that is patient-triggered. When you feel an episode of A-Fib, you press a button to record several minutes of the A-Fib episode. (It's actually recording all the time. When you press the button, it captures some minutes before you press the button and for some time after.) It's called a Transtelephonic Monitor if you call in to transmit the signals you recorded.
    Some Event (Loop) monitors start automatically when they sense abnormal heart rhythms. You don't need to press a button when you feel an A-Fib episode.

Exit Block:

An A-Fib signal is blocked by ablation lesions from leaving the pulmonary veins and affecting the rest of the left atrium. This is a goal of a successful A-Fib ablation, along with Entrance Block. Entrance and Exit Block are called Bidirectional Block.

FACC:

Fellow of the American College of Cardiology. Designates a Cardiologist who has completed a minimum of ten years of clinical and educational preparation and passed a rigorous two-day exam given by the American Board of Internal Medicine. It's not an absolute requirement for an EP, but most EPs have passed this Cardiology Board exam.

FDA:

See Food and Drug Administration.

FHRS:

Fellow of the Heart Rhythm Society. Not an academic title and not limited to physicians. Membership is based on peer review. Designates heart rhythm professionals working in the field of electrophysiology and/or pacing, provided that the majority of their time is not devoted to marketing and/or sales. Most EPs in the US with FHRS credentials have also achieved FACC. Internationally this may not be the case. 

Fibrillation:

Rapid, uncoordinated contractions of individual heart muscle fibers.

Fibrosis:

Hardened tissue in the atrium. A condition occurring in A-Fib where the heart develops fiber-like characteristics       in place of the normal smooth walls of the heart. Fibrosis seems to be linked to A-Fib.

First-line Therapy:

Based on medical guidelines of protocols, the doctor's typical first choice of treatment. 

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 and mapped to identify A-Fib signals sources.

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.

Food and Drug Administration:

U.S. government agency that regulates pharmaceutical drugs and medical devices.

Fresh Frozen Plasma (FFP):

The liquid portion of human blood that has been frozen and preserved quickly after a blood donation. In cases where someone with A-Fib is taking a blood thinner like Coumadin and is in a serious accident with extensive bleeding, FFP is administered which has clotting factors to stop the bleeding.

GLA:

Gamma-Linolenic Acid, an omega-6 fatty acid

Heart Attack (Myocardial Infarction):

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

Heart Block:

The heart beats too slow (bradycardia) because something causes the AV Node to delay or prevent the electrical signal from traveling from the atria to the ventricles.

Heart-lung Machine:

See Cardiopulmonary Bypass.

Hemorrhagic Stroke:

A stroke caused by bleeding.

Holiday Heart:

Term used to describe A-Fib admissions over weekends and holidays when more alcohol is consumed.  

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. It is also used in patients who have V-Tach (Ventricular Tachycardia). ABLATION FOR V-TACH (VENTRICULAR TACHYCARDIA) AT MASS. GENERAL BY DR. VIVEK REDDY 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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Ischemic Stroke:

A stroke that comes from a clot, the kind that most often occurs in A-Fib.

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.

Left Atrioventricular Valve:

See Mitral Valve.

Lesions:

In Catheter Ablation of A-Fib, lesions are electronically created cuts or scars. In surgery they are cuts made with a scalpel (i.e., traditional Maze operation).

Ligament of Marshall:

A vestige of a vein that was required during fetal development, but is no longer needed.

Long-standing Persistent Atrial Fibrillation:

When the heart remains in A-Fib all the time, as contrasted with Paroxysmal A-Fib where the heart has occasional attacks of A-Fib, or Persistent A-Fib where A-Fib attacks last longer than a week (formerly referred to as Permanent or Chronic A-Fib).  

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.

MAS:

Master of Applied Science

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.

Millisievert (mSv):

A measurement of radiation dose used for measuring the effects of various types or radiation. 1 Sievert equals 1.0 joule/killogram or 100 rem. A Sievert is defined as producing the same biological effect in a specific tissue as 1 gray of high-energy x-rays.

Mitochondria:

The part of a cell responsible for the production of energy in the form of ATP.

Mitral (Bicuspid, Left Atrioventricular) Valve:

The heart valve between the Left Atrium and the Left Ventricle. Oxygenated blood from the four Pulmonary Veins flows into the Left Atrium and through the Mitral Valve into the Left Ventricle. When the Left Ventricle pumps this blood into the Aorta and the rest of the body, the pressure of this blood pushes against the two folds or cusps of the Mitral Valve to close it. For an excellent video of how this valve works, go to http://www.youtube.com/watch?v=WXwYYsi6z7Q&feature=player_embedded       

MBBS (MBCHB, BMBS):

Bachelor of Medicine, Bachelor of Science. Awarded on graduation from medical school in various countries which follow the tradition of the United Kingdom. (Like an MD.)

MPH:

Master of Public Health

MSc:

Master of Science

mSv:

See Millisievert.

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.

Off-Label:

_{Outside of licensed indication---the clinical application of prescribed drugs for indications other than those approved by the FDA. Off-label uses are legal and may be in the best interests of patients. But they have not received the same degree of independent scrutiny through randomized clinical trials as have approved indications. One can not advertise or market a drug for something other than what has been approved by the FDA.}

Operating Room (O.R.) Report:

A very technical, detailed report by your ablation doctor describing step by step the procedures and results of an particular ablation. (Because it is very technical and difficult for patients to read, it isn't normally given to patients unless they ask for it.)

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.

Parasympathetic Nervous System:

The Parasympathetic Nervous system controls the heart, smooth muscles and glands of the head and neck, and thoracic, abdominal, and pelvic viscera. It's in control during periods of digestion and rest. Some research indicates a raised parasympathetic tone can lead to arrhythmias. http://www.normanallan.com/Sci/ANS.html
    The Sympathetic Nervous System enables the body to rise to emergency demands encountered in flight, combat, pursuit, and pain. It enervates and stimulates the body.

Paroxysmal Atrial Fibrillation:

Occasional attacks of A-Fib that return to normal heart rhythm (sinus rhythm) on their own, as contrasted with Persistent A-Fib or Long-standing Persistent A-Fib.

Percutaneous:

Through the skin. 

Persistent Atrial Fibrillation:

A-Fib that lasts more than a week, or that lasts less than a week but requires cardioversion to return to normal sinus rhythm.   

"Pill-in-the-Pocket" Treatment:

For Paroxysmal A-Fib patients. When an A-Fib attack occurs, the patient takes an antiarrhythmic med (flecainide, propafenone) to return to normal sinus rhythm. A variation of the Pill-In-The-Pocket treatment is to take an antiarrhythmic med on a regular basis, then take a higher dose at the time of an A-Fib attack.
    (There is some disagreement about this strategy. Some say it might be better to keep patients out of A-Fib by taking antiarrhythmic meds daily [keeping a fire from starting], rather than waiting for an A-Fib attack to start [having to put the fire out once it starts]. See Two Different "Pill-in-the-Pocket" Approaches 

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.

Post-Operative A-Fib:

Atrial Fibrillation which arises during or soon after cardiac surgery.

Pradaxa:

Brand name for dabigatran. Dabigatran is a direct thrombin inhibitor, a newer type of medication. Thrombin is an enzyme that converts soluble fibrinogen into insoluble fibrin. Fibrin is a fibrous protein involved in the clotting of blood. It forms a mesh or clot over a wound. Dabigatran does not require close monitoring and has less bad side effects than warfarin. It is expected to replace warfarin as the blood thinner of choice for A-Fib.

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 Valve:

The heart valve between the Right Ventricle and the Pulmonary Artery. The Pulmonary Valve opens as deoxygenated blood is pumped out of the right ventricle into the Pulmonary Artery to flow into the lungs to be oxygenated. When pressure in the Right Ventricle drops, the pressure of blood in the Pulmonary Artery will push the Pulmonary Valve closed. To see an excellent video of how this valve works, go to http://www.youtube.com/watch?v=WXwYYsi6z7Q&feature=player_embedded 

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 (PVA):

Catheter Ablation procedure to isolate A-Fib signals by ablating the openings around the pulmonary veins. Also called Pulmonary Vein Isolation (PVI).

Pulmonary Vein Antrum Isolation:

A type or method of Pulmonary Vein Ablation. Instead of making encircling lesions around each of the pulmonary veins, wider ablations encircle each of the two left and two right pulmonary veins in the Antrum area around the veins.

Pulmonary Vein Isolation (PVI):

Catheter ablation procedure to isolate A-Fib signals by ablating the openings around the pulmonary veins. Also called Pulmonary Vein Ablation (PVA).

Pulmonary Vein (PV) Potentials:

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

PVC:

Premature Ventricular Contraction. A type of irregular heart beat in which the ventricle contracts prematurely.  also known as VPB (Ventricular Premature Beat,) extrasystole, "skipped beat," or palpitations.

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.

The QT Interval:

In an EKG signal the QT interval represents the time the ventricles are pumping and at rest. See The EKG Signal.

The QTc Interval:

In an EKG signal the QTc Interval represents the time the ventricles are pumping and at rest corrected or adjusted for movement of the heart when beating. See The EKG Signal.

Radio Frequency (RF):

High frequency electrical energy used to form lesions or scar tissue in catheter and surgical ablations.

Radial Maze Surgical Ablation:

The newest refinement of the classic Maze surgery, sometimes called the Cox Maze IV. It replaces the surgeon's scalpel and "cut and sew" incisions with linear lesions (scars) created either with radiofrequency energy (heat) or cryo energy (freezing).  

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.

Recent-onset Atrial Fibrillation:

A term used to describe A-Fib during the first 48-72 hours of occurrence.

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.

Rhythm Control Medications:

Drug therapy that uses rhythm control drugs, called antiarrhythmics, to try to stop A-Fib and make the heart beat normally. 

RVT:

Registered Vascular Technologist. Must pass two exams given by the American Registry for Diagnostic Medical Sonography.

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.

Silent A-Fib:

Atrial Fibrillation in which the patient feels no or very few symptoms; often discovered only during a routine medical exam. 

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

Sudden Cardiac Death:
    Also called "cardiac arrest." Occurs when the electrical impulses in the heart become rapid (ventricular tachycardia) or chaotic (ventricular fibrillation) or both. This irregular heart rhythm causes the heart to suddenly stop beating. (This heart problem has received much less publicity than a Heart Attack.)

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.
    "Supraventricular Tachycardia" in clinical practice commonly refers to atrial tachycardia, atrioventricular nodal reentrant tachycardia (AVNRT), and atrioventricular reciprocating tachycardia (AVRT), an entity that includes Wolff-Parkinson-White syndrome. While Atrial Fibrillation is a distinct entity classified separately.
    The term "Supraventricular Arrhythmia" most often is used to refer to Supraventricular Tachycardias and Atrial Flutter.
    In practice, Supraventricular Tachycardia is often used to include all arrhythmias in the Atria, including A-Fib.

SVT:

See Supraventricular Tachycardia.

Sympathetic Nervous System:

The Sympathetic Nervous System enables the body to rise to emergency demands encountered in flight, combat, pursuit, and pain. It enervates and stimulates the body.
    The Parasympathetic Nervous system controls the heart, smooth muscles and glands of the head and neck, and thoracic, abdominal, and pelvic viscera. It's in control during periods of digestion and rest.

Symptomatic Atrial Fibrillation:

Atrial Fibrillation with noticeable symptoms (versus asymptomatic or Silent A-Fib) 

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.

Tambocor:

See Flecainide.

Tamponade:

Blood or fluid collects in the pericardium, the sac around the heart. This pressure can prevent the heart from beating and feel like one is being strangled. Doctors need to drain this fluid or blood from the pericardium.

TEE:

See Transesophageal Echocardiogram

Tikosyn:

See Dofetilide.

TIA:

Transient Ischemic Attack, a temporary "mini-stroke"

Tilt Table Test:

This test is typically performed to help diagnose the cause of dizziness and fainting. The individual is placed on a table that tilts upward, and the table is then placed at an approximately upright position so the individual is standing. Heart rate and blood pressure are monitored during the test. If no symptoms occur, a medication may be given to increase the heart rate in an attempt to reproduce the symptoms.

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  high-frequency ultrasonic waves to visualize structural and functional abnormalities of the heart from behind it within the esophagus.

Tricuspid Valve:

The heart valve between the right atrium and the right ventricle. The right atrium receives deoxygenated blood, then pumps it into the right ventricle through the Tricuspid Valve. This valve then closes as the right ventricle pumps this deoxygenated blood into the Pulmonary Artery. The pressure of the blood being pumped out of the right ventricle closes the three curved flaps or cusps of the Tricuspid Valve. For an excellent video of how this valve works, go to http://www.youtube.com/watch?v=WXwYYsi6z7Q&feature=player_embedded   

Ultrasound:

High-frequency sound vibrations used in some types of Catheter Ablation to produce images of the heart and vessel structure.

Vagal & Adrenergic 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 VagalA-Fib .
    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?"

Vagal Tone:

Impulses from the Vagus nerve inhibit and slow the heartbeat.

Ventricles:

The lower chambers of the heart. See Overview.

Ventricular Tachycardia:

A fast heart rhythm that originates in one of the ventricles. It is a potentially life-threatening arrhythmia, because it may lead to Ventricular Fibrillation---very rapid uncoordinated fluttering contractions of the ventricles resulting in loss of synchronization between heartbeat and pulse beat. Unlike A-Fib, it can be very dangerous and result in sudden death.

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

V-Tach (VT):

Short for Ventricular Tachycardia.  A fast heart rhythm that originates in one of the ventricles. It is a potentially life-threatening arrhythmia, because it may lead to Ventricular Fibrillation---very rapid uncoordinated fluttering contractions of the ventricles resulting in loss of synchronization between heartbeat and pulse beat. Unlike A-Fib, it can be very dangerous and result in sudden death.

Warfarin:

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

Watchman Device:

The theory behind the Watchman Device is most A-Fib clots originate in the Left Atrial Appendage (LAA). The Watchman Device closes off the LAA where 90-95% of A-fib strokes come from. It's a very low risk procedure that takes only a short time to install. Then you would usually not need to be on blood thinners.
    Here's how it works:
Once a patient's Left Atrial Appendage is measured, a wide-sheathed catheter with a spline is used to insert the Watchman device which has a self-expanding Nitinol (a special metal) open-ended circular frame. The atrial surface of this frame is covered with a thin, permeable 160 μm (micron) pore filter made of polyester material (Polyethylene Terephthalate known as Dacron or PET). This filter allows blood to pass through while stopping clots. Little hooks or anchors called fixation barbs at the middle of the device make sure it is attached firmly to the LAA wall. The Watchman device comes in multiple sizes from 21mm to 33mm to accommodate the different sizes of LAAs.
     Before the catheter is removed (which fixes the Watchman device in place), contrast agents are used to make sure the Watchman device is stable and entirely closes off the LAA opening. Over time heart tissue grows over the polyester (PET) material so that it completely closes off the LAA with smooth heart tissue similar to other heart surfaces. In this Occlusion slide, heart tissue has completely covered the Watchman device after only nine months.
    Some doctors are inserting the Watchman device in as little as 20 minutes. It is a low risk procedure with no surgery or ablation involved.
    Patients on Coumadin continue to take it for six weeks after the Watchman device is inserted. They are then examined using a TEE (Transesophageal Echocardiogram) to make sure there is complete closure of the LAA. At that time they are taken off of Coumadin.

    You can see a video of how the Watchman device is deployed at http://www.atritech.net/animation.html

    Think of the Watchman device as a replacement for Coumadin or other blood thinners. Coumadin reduces but does not totally eliminate the risk of stroke. Even with the proper INR levels of Coumadin, a small number of people with A-Fib have had strokes. The Watchman device also reduces but does not totally eliminate the risk of stroke. Like Coumadin, the Watchman is not an absolute guarantee one will never have a stroke. It basically reduces the risk of stroke similar to that of a person with a normal heart.
    If you hate having to take Coumadin or blood thinners or are allergic to them, you will be able to go in for a very low risk procedure that takes as little as 20 minutes, and replace Coumadin and blood thinners with the Watchman.  
    Even while you are waiting for or trying to decide on having a Pulmonary Vein Ablation, you can have the Watchman inserted and reduce your risk of stroke similar to that of a person with a normal heart.
    The Watchman device may become part of most catheter ablation procedures. If the catheter ablation procedure were unsuccessful or in case of silent A-Fib attacks after ablation, patients would still be protected from an A-Fib stroke by the closing off of the Left Atrial Appendage. The Watchman Device will probably become standard therapy not just for people with A-Fib, but also for anyone at risk of a stroke.
    Though still in clinical trials, the Watchman Device is available for most people. For a list of US doctors installing the Watchman Device, go to Doctors Installing the Watchman Device.

Wolf Mini-Maze:

A version of the Mini-Maze surgery for A-Fib developed by Dr. Randall Wolf, MD.

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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(This page last updated 2/21/12)