Rces Study Basic Electrophysiolgy Study

Front 1

1. Threshold

Back 1

These are assessed prior to starting the EP study.The minimum amt. of MA necessary to start depolarization. The MA is usually set twice the threshold

Front 2

2. Corrected QT (QTC) = Bazett's Formula

Back 2

QT Interval(msec) / √ (RR interval sec.)Normal QTc ≤ 440 msec.(know the normal )

Front 3

3. A longer QTc puts the patient at increased risk for???

Back 3

torsade de pointes

Front 4

4. Some causes of prolonged QT

Back 4

CAD,Cardiomyopathy,Severe Bradycardia, High-Grade AV BlockAnti-Arrhythmics, Psychotropic Drugs, Low Mag and calcium ,Hypothermia, Congenital Long QT Syndrome

Front 5

5. Milliamps (MA)

Back 5

A measurement of energy needed to overcome the threshold andinitiate a contraction.

Front 6

6. True or falseThe smaller surface area of the diagnostic 1 mm. tip electrode catheter is better at concentrating the energy into the tissue to start a depolarization than the 4mm tip

Back 6

True

Front 7

7. True or false The larger 8 mm ablation electrodes have more surface area require moreMA's to be able to concentrate enough energy into the muscle

Back 7

True

Front 8

8. Stimulator

Back 8

This is the equipment in the EP lab that is delivering the energy to pace. It is very sophisticated and can be programmed to deliver stimulus at 4 different intervals if required. Ours is called a Bloom stimulator

Front 9

9. This channel is set to deliver the drive train, the first stimulus.The drive train is 8 normal beats that the heart is paced at prior to introducing an extra stimulus. The cycle length (distance from one paced beat to the next) is started at 600ms.

Back 9

S1 Stim1 Stimulator1

Front 10

10. This is the second stimulus or the first premature beat to beintroduced after the drive train. It will be programmed to come in earlier than 600 ms. Depending on where you are in the protocol, it may be as early as 250ms

Back 10

S2 Stim2

Front 11

11. This is the third stimulus or the second premature beat. Again programmed to enter earlier than 600 ms and as early as 250 ms.

Back 11

S3 Stim3

Front 12

12 This is the fourth stimulus and programmed to enter early.The premature beats are not always programmed to enter at the same time.

Back 12

S4 Stim4

Front 13

13. This term Refers to a series of rapid beats by pushing a button until thedesired number of beats have been delivered.

Back 13

Burst Pacing

Front 14

14. Reference Surface EKG

Back 14

Gross electrical activity of the heart is recorded by surface EKG and is used as areference to the intracardiac signals.• Skin electrodes are stationary and always look at the electrical activity in the same way. Intracardiac electrodes (catheters) can move due to heart movement or be manuallymoved.

Front 15

15. Identifying A, H and V on Electrogram One bipolar intracardiac signal requires looking between two electrodes, one is_________and one is__________

Back 15

positive and negative

Front 16

16. Normal Activation Sequence OF INTRACARDIAC ELECTROGRAMS

Back 16

The A on the HRA should be the first to be activated, as it is closest to SA node.• The A on the HIS catheter should be the next to be activated and finally the A on theCS catheter.• The A on the CS catheter is later, as is has a longer way to travel.• If the A on the CS catheter were to be activated around the same time as the HIS A,then it is somehow getting over to the CS catheter via a “shortcut” pathway.

Front 17

17IN Atrial Pacing, where is the RA catheter placed

Back 17

The HRA catheter is being used to pace close to the SA node

Front 18

18.The pacing spike will initiate atrial depolarization; where will the spike be seen on surface ekg

Back 18

it will be immediatelybefore the P wave.

Front 19

19 What will the QRS look like when pacing the atrium

Back 19

Since it goes down the normal conduction system to the ventricle, the QRS will looknormal and narrow

Front 20

#20 What is the antegrade conduction sequence?

Back 20

The antegrade conduction sequence will be A-H-V.

Front 21

#21 To deliver a stimulus in the ventricle the ____ catheter is used.

Back 21

RVA

Front 22

#22 In RV pacing, the ventricle is depolarized on the right side; then the impulse has to propagatethrough the muscle and across the septum to the left side. What will the QRS look like

Back 22

The length of the ventricular depolarization will be longer than normal because it hasto travel from one side to the other through muscle. A very wide QRS is the result.

Front 23

#23 In RV pacing,The pacing spike will be in front of the QRS since the ventricle is activated first and the P wave will be______ _______ the QRS

Back 23

buried inside

Front 24

#24 The retrograde intracardiac activation sequence will be___ ___ ___

Back 24

Retrograde V-H-A

Front 25

#25 Time in EP is measured in milliseconds (ms). Change .20sec to ms.

Back 25

example .20sec = 200msmove the decimal point 3 places

Front 26

#26 A ___is the measurement in time between two heartbeats. It is generallymeasured from A to A.

Back 26

cycle length

Front 27

#27 If the patient is in an atrial tachycardia, THE A TO A would reflect the cycle length of the _____.

Back 27

THE TACHYCARDIA

Front 28

#28 INTRAATRIAL CONDUCTION TIME

Back 28

Interval between the P wave on the surface EKG and the "A" deflection on the HIS catheter.This reflects time between the SA and AV node

Front 29

#29 Baseline intracardiac intervalsPA, AH, HV

Back 29

PA 10-45msAH 55-130msHV 30-55msP and the V are measured from the surface or intracardiac, wherever they first appear

Front 30

#30 P-R Interval - Measures the time the impulse takes to travel where to where?

Back 30

P-R Interval - Measures the time the impulse takes to travels from the SA node through the AV node to the HIS. 120-200ms

Front 31

#31 QRS duration Measures the time the impulse takes to travel where to where?

Back 31

QRS Duration - Measures the time the impulse takes to go through the HIS Purkinje system 60-100ms

Front 32

#32 A long QRS indicates

Back 32

A block in one of the bundle branches.

Front 33

#33 QT Interval - IS Measured from where to where

Back 33

the beginning of the QRS to the end of T wave.

Front 34

#34 A long QT can be associated with

Back 34

Sudden death from VT Known as Torsades de Pointe. It can be congenital or induced by medications. Normal QT between 0.36 and 0.44 second, but varies depending on heart rate, sex and age. The QT interval should be less than half the distance between consecutive R waves (called R to R interval). Corrected QT interval=QT Interval / √ (RR interval)Normal QTc ≤ 440 msec.

Front 35

#35 Basic cycle length (BCL)

Back 35

The heart rate measurement in milliseconds. Measure from A to A or V to V

Front 36

36. Name three indications for an EP study

Back 36

SyncopeBradyarrhythmiasTachyarrhythmias

Front 37

#37.Antegrade conduction

Back 37

Conduction from high to low (A-H-V)

Front 38

#38. Retrograde Conduction

Back 38

Conduction from low to high (V-H-A)

Front 39

# 39 Decremental pacing

Back 39

To decrease (make faster) The cycle lengths between paced beats are progressively shortened

Front 40

#40 Incremental pacing

Back 40

A finite change (increase or decrease) in the variable.Incremental Atrial Pacing (IAP) - Pacing within the atrium at shorter and shorter cycle lengths which increases the heart rate until a beat is dropped. (Wenkebach cycle length)Incremental Ventricular Pacing (IVP) - Pacing within the ventricle at cycle lengths to assess V-A conduction and retrograde Wenkebach.

Front 41

# 41 Drive Train

Back 41

A fixed number S1 beats to set an electrically stable environment. 6, 8 or 10 are commonly used as S1 beats. ie:A series of eight paced beats at a constant cycle length followed by premature beats. (Referred to as S1.)

Front 42

#42 SCL Sinus Cycle length

Back 42

SCL measurement of atrial depolarization to atrial to atrial depolarization,A-A

Front 43

#43 A-H intervalwhere to measurenormal value

Back 43

Purpose – measures conduction time from the low right atrium through the A-V node to the Bundle of His.Method – measured from the earliest rapid deflection of the atrial electrogram in the His bundle lead to the onset of the His deflection.Considerations – may vary during a single study up to 20 msec, due to changes in the patients autonomic tone.Normal range – 50-140 msec.

Front 44

#44 H-V intervalwhere to measurenormal value

Back 44

Purpose – measures conduction time from the proximal His bundle thru the his purkinje system to the ventricular myocardium.Method – measured from the beginning of the His bundle deflection to the earliest onset of ventricular activation, usually found in the surface electrograms.Considerations – not effected by variations in autonomic tone; may vary from study to study depending on antiarrhythmic medication.Normal range - 35 – 55 msec.

Front 45

#45 Define SNRT and how and why it is performed.

Back 45

The length of time it takes for the SA node to recover after atrial pacing to suppress the SA node has terminated. It is a test of theautomaticity of the SA node, generally done in-patients thought to have SSS. The interval from the last pacing spike to the first A on the HRA catheter is measured. A normal corrected value is less than 550 ms.

Front 46

#46 What is the method to calculate a corrected SNRT?

Back 46

cSNRT are calculated by measuring the SCL before pacing and then subtracting this from the SNRT.SNRT = 1200 msSCL = 780 ms cSNRT = 420 ms

Front 47

#47 The Patient has a SNRT of 1400msand a Sinus Cycle length of 880msCalculate the cSNRT

Back 47

520ms

Front 48

#48 What is a normal cSNRTthis is on test!!!

Back 48

<550ms

Front 49

#49 IAP Incremental atrial pacingWhat does it do and how is it done?

Back 49

Pacing within the atrium at shorter and shorter cyclelengths which increases the heart rate until a beat is dropped. (Wenkebach cycle length). The decremental properties of AV node will be reflected in the AH interval.• The AH interval will gradually prolong until the beat is dropped.• The Wenckebach cycle length is the cycle length paced at the time of block.• AV node should block in the 380 - 420 ms. range.

Front 50

#50 Incremental ventricular pacing (IVP)Why and where is it done?

Back 50

Analyzes the functional properties of the VA conduction system. Usually measured by pacing in the RVA. The pacing cycle length is started just below the sinus cycle length and gradually decreased (paced faster).Wenckebach VA 2:1 VAconductionSometimes during this protocol VT is initiated

Front 51

51. Effective Refractory period, how is it obtained? ERP

Back 51

Evaluated by pacing the HRA, RVA. Measured by a train of paced beats followed by decrementing prematuresThe LONGEST coupling interval for a premature stimulus which DOES NOT conduct

Front 52

#52 What are the events you will see when testing for Effective refractory periods?

Back 52

AVN ERP, AH Jump, A ERPVA ERP, V ERPVTSVT

Front 53

#53 AV Node Effective Refractory Period (AVNERP)

Back 53

AV Node Effective Refractory Period (AVNERP)The assessment of the refractory time of the AV node.• This will determine if a patient has dual AV nodal physiology.• Refractory times for both the fast and slow pathways.• Premature Atrial Contractions PAC are inserted at shorter and shorter cycle lengths until the AV node is refractory. The impulse is not able to exit the AV node to depolarize the His.• Normal values are 230-430 ms.

Front 54

#54 AERP Atrial Effective Refractory Period How do we test ?

Back 54

The assessment of the refractory period of the group of cells in the atrium.• Atrium is paced and S2’s are inserted at shorter cycle lengths until the tissue isrefractory.• It is the cycle length that does not conduct the beat through the atrium.• Normal value is 150 - 360 ms.

Front 55

#55 VERP - Ventricular Effective Refractory Period How do we test?

Back 55

VERP - Ventricular Effective Refractory Period• The assessment of the refractory period of the ventricular tissue.• PVC's are inserted at shorter coupling intervals until the stimulus does not produce ventricular depolarization (no QRS or V).• The longest coupling intervals that block the beat, is the VERP.• Normal - 170 -290 ms.

Front 56

#56 VA conduction or VA effective Refractory Period VAERPHow do we testDoes everyone have it??

Back 56

VA conduction• 30 % of population has no VA conduction.• RVA catheter used to pace ventricle until 1 to I conduction is lost.• Every V or QRS should be followed by an A on the HRA catheter.

Front 57

#57 Supra Ventricular Tachycardia (SVT)Arrhythmia induction induced by:

Back 57

Induced by:Prematures in sinus rhythm Paced drive train (600, 500, 400, 350)With prematures S2, S3, S4 from HRA Paced drive train (600, 500, 400, 350)With prematures S2, S3, S4 from RVA, RVOT Burst atrial pacing

Front 58

#58 Ventricular TachycardiaArrhythmia induction induced by:

Back 58

Induced by: One two and three prematures in sinus rhythm Paced drive train (600, 500, 400, 350) with prematures S2, S3, S4 from RVA RVOT Burst Ventricular pacing RVA RVOT

Front 59

#59Define : A-H Jump

Back 59

A patient having dual AV node physiology will have two limbs inserting into the compact node. Each of the limbs will have different refractory times. If the A-H interval increases greater than 50 ms from the previous stimulus (a premature stimulus will be introduced 10 ms earlier) it is said that there is a significant JUMP.