ECGs And Intro To EP Lab

Question 1

Electrogram

Answer 1

An electrical recording from inside of the heart, using catheters placed in specific anatomical locations.

Question 2

Activation Sequence

Answer 2

The order in which the electrical signals are recorded as they travel through the heart.

Question 3

Unipolar Electrogram

Answer 3

Uses one positive electrode and a negative reference point located remotely, such as Wilson’s Central Terminal.

Question 4

Bipolar Electrogram

Answer 4

An electrogram that measures the electrical potential between two electrodes (one positive and one negative) that are placed close together within the heart.

Question 5

HRA

Answer 5

High Right Atrium: An EGM catheter location near the sinus node that measures whether the SA node is generating an electrical signal.

Question 6

HBE

Answer 6

His Bundle Electrogram: An EGM catheter location in the His bundle (across the tricuspid valve annulus) that measures electrical signals in the right atrium, His bundle and right ventricle.

Question 7

CS

Answer 7

Coronary Sinus: An EGM catheter location in this blood vessel located in the posterior of the heart between the left ventricle and left atrium, which measures electrical signals in the left atrium and left ventricle.

Question 8

RVA

Answer 8

Right Ventricular Apex: An EGM catheter location in the apex (lowest) part of the right ventricle, which allows the EP to measure electrical signals and pace in the right ventricle.

Question 9

Gain

Answer 9

An EGM filter that increases or decreases the displayed amplitude of the electrical signal.

Question 10

Clipping

Answer 10

An EGM filter that clips the display of the top and bottom of the signal on the monitor so that two adjacent signals don’t overlap.

Question 11

High-pass

Answer 11

An EGM filter that allows signals higher than a certain frequency to be displayed on the monitor, thus filtering out low-frequency signals.

Question 12

Low-pass

Answer 12

An EGM filter that allows signals lower than a certain frequency to be displayed on the monitor, thus filtering out high-frequency signals.

Question 13

AH Interval

Answer 13

A baseline measurement that measures the conduction properties of the AV node.

Question 14

HV Interval

Answer 14

A baseline measurement that measures the conduction time from the HIS to the ventricle/Purkinje system.

Question 15

A-A Interval

Answer 15

A baseline measurement that measures the atrial electrogram to proceeding atrial electrogram on the HRA catheter, giving insight to intra-atrial conduction and refractory.

Question 16

R-R Interval

Answer 16

A baseline measurement that measures the R wave of the QRS to the proceeding QRS complex, giving insight to ventricular conduction velocity and refractory.

Question 17

Antegrade Conduction

Answer 17

The normal conduction between the atrium and the ventricle. In sinus rhythm, antegrade conduction starts in the atrium and conducts to the ventricle in the A-H-V pattern.

Question 18

Retrograde Conduction

Answer 18

Backwards or reverse conduction between the ventricle and the atrium; uses the normal conduction system starting in the ventricle and conducting to the atrium in a V-H-A pattern.

Question 19

Increment

Answer 19

A pacing maneuver that incrementally decreases the pacing cycle length to assess the conduction properties of the AVN.

Question 20

Decrement

Answer 20

A pacing maneuver that assesses the refractory periods of the atrium, bundle of HIS, and ventricle. A series of beats are delivered at a constant cycle length (drive train) followed by a premature (or extra) stimulation. This premature beat is decremented in delivery, decreasing the total time of recovery between stimulated beats.

Question 21

Coronary Sinus Vessel

Answer 21

The heart’s venous drainage system, located in the right atrium posterior and inferior to the tricuspid valve. It acts as a conduit for oxygen-poor blood from the heart muscle into the atrium.