Electrophysiology Terms A-C

Question 1

A-Wave

Answer 1

(1) atrial paced event

(2) atrial stimulus or the point in the intrinsic atrial depolarization at which atrial sensing occurs

Question 2

AA interval

Answer 2

the interval between two consecutive atrial stimuli, with or without an interceding ventricular event

Question 3

Aberrancy

Answer 3

Abnormal conduction in the native tissues resulting in a change in the sequence of activation ( hence, morphology ) of the atrial or ventricular depolarization. This is due to functional or pathological increases in physiologic refractory period a portion of the conduction systemm

Question 4

Absolute Refractory Period

Answer 4

Physiology: within the cardiac tissue, the period of time directly following depolarization. Where a new stimulus regardless of the strength, cannot initiate new depolarization

Question 5

Accessory Pathway

Answer 5

a conduction pathway connecting the atrium and ventricle which totally or partially bypasses the AV node. They provide anterograde or retrograde conduction of impulses and frequently are the anatomical basis for reentrant arrhythmia’s

Question 6

Active fixation lead

Answer 6

a lead with an attachment mechanism, such as a screw in tip or helix to actively secure it in the cardiac tissue at implant

Question 7

AH interval

Answer 7

the length of time taken for a depolarization wave to travel from the lower right atrium at the interatrial septum to the His bundle, as measured on an intracardiac electrogram. This interval approximates AV nodal conduction time. normal 50 - 120 ms

Question 8

Antitachycardic pacing (ATP)

Answer 8

Therapeutic intervention using standard bradycardia pacing algorithms and energy levels in an effort to bring the heart out of a tachycardia and restore its normal rhythm

Question 9

Automaticity

Answer 9

(1) Physiology: the ability of tissue to spontaneously generate an electrical impulse and propagare an action potential.
(2) Devices: the abilit of a device to recognize a need for a change in parameter settings and make these corresponding adjustments automatically

Question 10

AV dissociation

Answer 10

a condition which the atria and ventricles beat independently of each other without any synchronization of rhythms.

Question 11

Basic Cycle Length

Answer 11

the rate of sinus rhythm measured in milliseconds

Question 12

Bipolar

Answer 12

having two poles.
In pacing and ICD’s, a bipolar lead contains two distal electrodes. bipolar pulse generators are devices that can accommodate such a lead

Question 13

Burst pacing

Answer 13

several sequential, rapid stimuli delivered to the heart by an external or internal device in an effort to terminate or initiate a tachycardia

Question 14

Capture

Answer 14

the successful depolarization and contraction of a cardiac chamber caused by a pacemaker output pulse. One - to - one capture occurs when each pacemaker output pulse results in a contraction of the appropriate chamber

Question 15

Capture Threshold

Answer 15

the lowest pulse generator output which results in consistent capture

Question 16

Cardiac Mapping

Answer 16

an invasive eletrophysiology procedure used to identify accessory pathways. To identify atrial activation, to delineate the course of AV conduction, to assess the sequence of VA activation, and to locate the origin of tachycardias

Question 17

Cardioversion

Answer 17

the delivery of an electrical shock to the heart to synchronize the action potentials of all myocardial cells and to terminate arrhythmia’s.

Question 18

Coupling interval

Answer 18

the time between the last intrinsic beat and the first paced beat

Question 19

Current

Answer 19

the flow of electrons usually measured oast a specific point over time and traditionally expressed in amperes