glossary and abbreviations

Question 1

Accessory Pathway (AP)

Answer 1

An additional electrical connection (other than the AV node) between the atria and ventricles. Accessory pathways may conduct:

1. Antegrade only: generates a delta wave
2. Retrograde only: no delta wave
3. Bidirectional: generates a delta wave

Question 2

Action Potential

Answer 2

The waveform generated by a cell’s depolarization

Question 3

AEGM

Answer 3

Atrial Electrogram

Question 4

AF

Answer 4

Atrial Fibrillation

Question 5

A-H interval

Answer 5

transit time through the AV node

Question 6

Anisothropy

Answer 6

The concept that conduction velocity along a cardiac muscle fiber is determined by angle of initial depolarization

Question 7

Antidromic

Answer 7

Denoting a wave of depolarization that is traveling retrogradely though the AV node. This term is usually used when describing the direction of the wavefront of an atrioventricular reentrant circuit. In this scenario, the wave of depolarization travels down the accessory pathway and back up the AV node. It can also denote a wave of depolarization that is traveling in the opposite direction to the predominate wave. For instance, a clockwise wave of depolarization introduced into a counterclockwise atrial flutter, therefore called an antidromic wavefront.

Question 8

AP

Answer 8

Accessory Pathway

Question 9

Ashman phenomenon

Answer 9

When a relatively long cycle (R-R) is followed by a relatively short R-R, the QRS associated with the short R-R often has RBBB morphology. Often referred to a “long-shortening” the bundle branches. The right bundle branch has had insufficient time to adapt its ERP to a sudden change in heart rate. It therefore blocks.

Question 10

AT

Answer 10

Atrial tachycardia

Question 11

Atrial Fibrillation (AF)

Answer 11

A disorganized atrial rhythm associated with irregularly irregular ventricular response.

Question 12

Atrial tachycardia

Answer 12

It may originate in either the left or right atrium

Question 13

Atropine

Answer 13

A parasympatholytic used to increase heart rate

Question 14

AV

Answer 14

atrioventricular

Question 15

A-V

Answer 15

Referring to the total transit time from the atria to the ventricles

Question 16

AVCS

Answer 16

Refers to the atrioventricular conduction system

Question 17

AVNRT

Answer 17

AV nodal reentrant tachycardia

Question 18

AVRT

Answer 18

atrioventricular reentrant tachycardia

Question 19

Bipolar

Answer 19

Refers to the use of two poles (a positive and negative electrode) usually in close proximity to one another. However, a unipolar lead is just a very widely spaced bipole.

Question 20

Bundle of His

Answer 20

Anatomic structure connecting the AV node to the bundle branches. It is mostly a ventricular structure.

Question 21

Carto

Answer 21

A 3D mapping system from Biosense Webster

Question 22

CFEs

Answer 22

Complex fractionated electrograms usually associated with the left atrium during atrial fibrillation.

Question 23

Chevron

Answer 23

a pattern of activation where CS 1-2 activation is as early as CS 9-10 act while the remaining poles are later.

Question 24

Concealed

Answer 24

An unseen penetration of a wave of depolarization into a structure that subsequently affects the conduction properties of that structure.

Question 25

Contralateral

Answer 25

“On the other side.” Often used as “contralateral bundle branch block.” It refers to a LBBB pattern during a right-sided tachycardia or a RBBB during a left-sided tachycardia and the effect of that bundle branch block on the tachycardia.

Question 26

CS

Answer 26

coronary sinus

Question 27

CTI

Answer 27

cavotricuspid isthmus

Question 28

Decapolar

Answer 28

10-pole catheter. Often the CS catheter.

Question 29

Decrement

Answer 29

The ability of the AV node to slow conduction of a wave of depolarization

Question 30

Delta wave

Answer 30

A slurred, initial deflection of a widened QRS that represents early conduction directly into a ventricle via an accessory pathway.

Question 31

Depolarization

Answer 31

The process by which a cell changes on the inside from electrically negative to electrically positive.

Question 32

Digitization

Answer 32

The conversion of an analog signal to a digital signal

Question 33

Duo-Deca

Answer 33

a 20-pole catheter (2x10 poles)

Question 34

EGM

Answer 34

Electrogram

Question 35

Echo

Answer 35

An unexpected return of a wave of depolarization to the chamber where the wave originated

Question 36

Entrainment

Answer 36

A pacing maneuver where we pace slightly faster than the tachycardia cycle length, temporarily speeding up the tachycardia rate, then stopping pacing which allows the circuit to return to its initial cycle length. The main purpose is to determine how close to the tachycardia circuit the pacing catheter is.

Question 37

ERP

Answer 37

Effective refractory period. By definition it is the longest S1S2 that fails to conduct. Most of the time we are looking for the ERP of the AV node or an accessory pathway. With a very tight S1S2 (600, 200), you may reach the ERP of the myocardium itself (seen as no capture of the S2).

Question 38

Escape Rhythm

Answer 38

A heart rhythm initiated by focus outside the SA node.

Question 39

Far-field

Answer 39

cardiac electrograms that seem to be recorded either from a distance or due to poor contact. Usually smooth, low frequency electrograms.

Question 40

FP

Answer 40

AV nodal fast pathway, usually referring to the antegrade pathway

Question 41

FRP

Answer 41

Functional refractory period. Examples: 1) referring to the AV node, it is the shortest output (H1-H2) achievable in response to any S1S2 input, meaning that no decrement has yet to occur;
2) Referring to the ventricle, it is the shortest V1-V2 achievable from any S1S2 input, meaning that no latency has yet to occur.

Question 42

A

Answer 42

Atrial