Patients
Introduction
47266 Benicia Street
Fremont, CA 94538-7330
United States
Telephone: 510-354-0300
Toll Free: 888-354-0300
Glossary
A
ACUTE: Sudden onset
ANASTOMOSIS: Surgical, traumatic or pathologic formation of a connection between two normally distinct structures.
ANGINA: Spasmodic, choking or suffocating pain. Now used exclusively to denote angina pectoris.
ANGINA PECTORIS: Severe constricting pain in the chest, sometimes radiating from the region of the heart to the left shoulder and down the arm due to the temporary inadequacy of blood to the heart muscle.
ANGIOGRAM: An X-ray examination of the heart arteries using a radiopaque dye injected into the bloodstream.
ANGIOPLASTY: Plastic repair of blood vessels or lympatic channels.
ANTIARRHYTHMIC: Preventing or alleviating cardiac arrhythmias.
ANTICOAGULANT: A drug which delays blood clotting.
AORTA: Main artery carrying oxygenated blood from the left ventricle to other arteries and all parts of the body.
AORTIC VALVE: Valve between the aorta and left ventricle.
ARREST: Any cessation of activity often applying to the heart itself and specifically applying to cessation of the heart’s electrical and mechanical activity.
ARRHYTHMIA: Any abnormal rhythm of the heart, with respect to its rate of regularity or the shape of its waveform.
ARTERIES: Vessels which carry oxygenated blood from the heart (the exception to which is the Pulmonary Artery, which carries de-oxygenated blood from the heart to the lungs).
ARTERIOSCLEROSIS: Hardening of the arteries due to thickening and loss of elasticity.
ASYSTOLE: Period in which the heart does not contract; standstill.
ATHEROSCLEROSIS: A form of arteriosclerosis in which deposits of yellowish plaque containing cholesterol, lipid material, and lipophages are formed within large and medium-sized arteries.
ATRIUM: The upper chamber of the heart (plural: ATRIA). Acts as a reservoir for blood awaiting transit to the ventricles.
AV NODE (or ATRIO-VENTRICULAR NODE): located in the lower portion of the right atrium, the AV Node is responsible for slowing the electrical signal propagation prior to its transit to the Bundles of His. This corresponds to the pause between contraction of the Atria and the Ventricles.
B
BPM: Beats per minute.
BRADY: Slow.
BRADYCARDIA: Low heart rate, usually defined as below 60 bpm in a conscious person.
BUNDLES OF HIS: The electrical conduction pathways located in the ventricles on either side of the septum.
C
CANNULATE: To introduce a cannula, referring to the placement of a guide or catheter into ostium of artery or vein.
CARDIAC: Pertaining to the heart.
CARDIAC ARREST: Cessation of ventricular activity; lack of heartbeat of peripheral pulse.
CARDIMYOPOTHY: Enlargement of the heart.
CARDIOPULMONARY BYPASS: A procedure used to circumvent the flow of blood through the heart and lungs while a surgical procedure is being done.
CARDIOVASCULAR: Refers to the heart and blood vessels, seen as a total system.
CARDIOVERSION: DC synchronized electrcal shock administered to restore cardic rhythm.
CATHETER: Tubular or solid linear structure intended for insertion into a blood vessel, duct, or passage.
CATHETERIZATION: Examination of the heart by means of a thin catheter inserted into a vein or artery.
CHRONIC: Long duration.
COAGULATION: Process whereby blood thickens to solid state, as in formation of a clot.
COMPENSATION: A change in any part or system to make up of some other inadequacy or deficiency (e.g., the heart may increase its muscular contractllity to compensate for an abnormally functioning region).
CONGENITAL: Indicates any disease or abnormality caused by genetic factors.
CONGESTIVE HEART FAILURE: When the heart is unable adequately to pump out all the blood that returns to it, there is a backing up of blood in the veins leading to the heart.
CORONARY ARTERIES: Arteries which supply blood to the heart muscle.
CS: Coronary Sinus
D
DIASTOLE: The period of time in the cardiac cycle when the heart is resting or filling with blood.
DILATATION: The stretching or enlargement of the heart or blood vessels.
DISTAL: Far from origin.
DYE: Contrast material used in X-ray.
DYSPNEA: Labored or difficult breathing.
E
ECHOCARDIOGRAPHY: A diagnostic technique used for cardiac function whereby sound pulses are transmitted into the body to the heart and the returning echoes are electronically recorded.
EDEMA: Excessive fluid accumulation in the tissues.
EKG: Electrocardiogram; also abbreviated ECG
ELECTROCARDIOGRAM (ECG): Record of potential difference produced over time at two or more locations on the skin. The ECG reflects depolarization and repolarization of myocardium.
ELECTRODE: In pacing, the electrodes are considered to be the stimulating portion of the pacing lead. These electrodes must be in contact with the internal or external surface of the heart, or, in the case of indiffferent electrodes, they must be in contact with a portion of the body.
ELECTROPHYSIOLOGY: The study of the electrical conduction system of the heart.
EMBOLUS: A plug, composed of a detached clot mass of bacteria or foreign body, occluding a blood vessel.
ENDOCARDIUM: Smooth inner lining of the heart.
EPICARDIUM: The smooth, lubricated tissue that protects the heart against friction.
ETIOLOGY: The sum of knowledge about the cause of a disease.
EXTRASSYTOLE: Premature contractions of the heart which interrupt the normal rhythm.
F
FIBRILLATION: Chaotic, high-rate, unsynchronized quivering of the myocardium resulting in ineffectual cardiac pumping.
FIBROSIS: Scarring of the heart or other organs of the body. Within the conduction system of the heart, this scarring may cause heart block or other rhythm disturbances.
FLUOROSCOPY: Examination of an internal structure by a continuous viewing of shadows formed by differential transmission of X-ray through the objects.
G
H
HEART BLOCK: A condition in which impulses are not conducted in the normal fashion from the atria to the ventricle. A form of arrhythmia caused by damage or disease processes somewhere in the tissue of the A-V junction. Three types: 1st degree, 2nd degree, and 3rd degree.
HEMODYNAMICS: The study of the flow of blood and the forces involved.
HYPERTROPHY: Excessive development or growth of an organ, tissue, or cellular mass.
HYPOXIA: Oxygen deficiency in blood tissue.
I
INFARCT: Area of tissue which is deprived of blood supply and is permanently damaged.
INTRACARDIAC: Within a chamber of the heart.
INTRINSIC: Inherent, originating from the structure or organ itself.
IN VITRO: in glass, study conducted under laboratory conditions.
IN VIVO: In life; study conducted in a living body.
ISCHEMIC TISSUE: Tissue which has inadequate blood supply to maintain normal function.
J
K
L
LUMEN: The open inner space of any tubular organ, as of a blood vessel.
LESION: Any change or discontinuity to tissue or loss of function of a part.
M
MEDIASTINUM: Bony/cartilaginous space in the center of the chest between the lungs, starting at the lower margin of the throat and extending to te diaphragm.
MITRAL VALVE: The atrio-ventricular valve on the left side of the heart.
MYOCARDIAL INFARCTION: The damaging or death of an area of the heart muscle resulting from a reduction in the blood supply reaching that area. It is abbreviated MI or AMI.
MYOCARDIUM: The muscular heart wall, lying between the inner and outer layers of the heart, which contracts and relaxes when pumping blood to and from the heart.
N
O
O2: Chemical symbol for oxygen.
OUTFLOW TRACT: Areas of the right ventricle where blood flows out toward the pulmonary artery.
P
PALPITATION: A sensation of fluttering or skipping of the heart.
PERCUTANEOUS: Effected through the skin; introduction of an endocardial lead through a small puncture in the skin and into a vein.
PERICARDIUM: Outer fibrous sac containing the heart.
PULMONARY ARTERY: The only artery which transports de-oxygenated blood, it connects the right ventricle to the lungs.
PULMONARY VALVE: The one-way valve between the right ventricle and the Pulmonary Artery.
PULMONARY VEINS: The vasculture which connects the lungs to the left atrium. They are the only veins which transport oxygenated blood.
PURKINJE FIBERS: The final electrical conduit in the circuit, the Purkinje Fibers are located in the ventricle walls and help to trigger ventricular contraction.
Q
R
REFRACTORY: Not yielding or responding to therapy, e.g. anti- arrhythmic drugs becoming ineffective over time.
S
SEPTUM: The dividing wall between the chambers of the heart.
SINUS NODE: Origination of the heart's electrical activity, the Sinus Node (or SA Node) is located in the upper portion of the right atrium.
STOKES-ADAMS SYNDROME: A characteristic group of symptoms due to complete heart block, with the heart functioning in an idioventricular rhythm. The symptoms are slow rate, dizziness, fainting and convulsions.
STROKE VOLUME: The amount of blood which is pumped out of the heart at each contraction of the heart.
SUPRA-VENTRICULAR TACHYCARDIA (SVT): The rapid heartbeat caused by accessory pathways emanating in the atria.
SYNCOPE: A brief period of unconsciousness caused by an insufficient supply of blood to the brain. Dizziness.
SYSTOLE: The phase in the cardiac cycle in which the myocardium of the ventricles is electrically and mechanically active (i.e., contracts and ejects blood).
T
TACHYCARDIA: Rapid heart rate, usually considered tachycardia if over 100 bpm.
TELEMETRY: The circuitry required to monitor, measure and transmit various parameter values within the pulse generator to an outside receiver.
THORACOTOMY: An operation in which the chest wall is surgically opened between the ribs, and the pleural space is entered. A procedure sometimes used for myocardial lead placement.
THROMBOEMBOLISM: A blood clot which forms in one site, detaches and lodges in another part of the body.
THROMBOSIS: The formation of a blood clot.
TRICUSPID VALVE: The atrio-ventricular valve connecting the right atrium to the right ventricle.
TRIGEMINY: An arrhythmia with repeating groups of three complexes of different shape on an EKG.
V
VASCULAR: Relating to the blood vessels.
VEIN: A vessel which returns blood to the heart.
VENA CAVA: Either of two large veins which bring blood into the right atrium of the heart. Superior: head, neck and chest. Inferior: legs and abdomen.
VENOGRAM: The fluoroscopic study of the venous side of the vasculature.
VENTRICLE: One of the two lower chambers of the heart. Left ventricle pumps oxygenated blood through arteries to the body. Right ventricle pumps unoxygenated blood through the pulmonary artery to the lungs.
VENTRICULAR TACHYCARDIA (VT): A series of arrythmogenic foci in the ventricles (usually the left) causing an elevated heart-rate. VT is difficult to map and ablate.
VISCERAL: The inner layer of the pericardium which is in contact with the heart.
W
WAVEFORM: Shape or morphology of an electronic pulse over time, as viewed on an oscilloscope.