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Flashcards in Timing cycles Deck (58):
1

What does the 1st column in the NGB code dictate

Chamber Paced

2

What does the 2nd column in the NGB code dictate

Chamber Sensed

3

What does the 3rd column in the NGB code dictate

Action (Inhibit or trigger)

4

When do we use asynchronous pacing

Uused only transiently for pacing-dependant patients to avoid inappropriate pacing inhibition during interventions or surgeries associated with noise.

5

Why use a triggered mode

Excellent marker for the site and time of sensing within a complex in an ECG tracing.

6

4 modes of DDD pacing

As Vs
As Vp
Ap Vs
Ap Vp

7

4 States of DDD pacing

AV
PV
PR
AR

8

AV delay + Pvarp =

TARP - Total atrial refractory period

9

In DDD pacing a V output cannot be delivered unless.....what

Some atrial event occurs to start the AV Delay interval.

10

if RR is programmed off, what will be the atrial pacing rate

ALWAYS as base rate / LRL

11

PV delay = SAV TRUE OR FALSE

TRUE - AKA P Tracking Interval, PV Interval

12

Describe Pacemaker wenckebach

Occurs when the sensed atrial rate (P waves) is faster than the programmed maximum tracking rate (or upper rate interval)

13

Below base rate ventricular pacing is NORMAL in VDD pacing TRUE/FALSE

TRUE

In VDD mode, if the atrial rate drops below the LRL, the mode will appear VVI

There is no atrial LRL as it is a sensed channel only

14

Define ventricular based timing

The sensed R wave causes the AEI/VAI timer to start

15

What will ventricular based timing due to the atrial rate

The next atrial output will occur at a rate that is faster than the programmed base rate

16

Define atrial based timing

The AEI timer begins with the atrial event.

17

PR state is AKA inhibited

True - no outputs are delivered in this state of DDD pacing

18

Why use DDI

To prevent tracking of atrial arrhythmias

19

In DDI the ventricular paced rate will never be greater than the programmed LRL regardless of the atrial rate - TRUE/FALSE

True - unless sensor driven

20

Which two pacing states cant be provided by VDI vs DDD

AS-VP (inhibition mode)

AP-VP (no A pace function)

21

DDI vs DVI

DVI senses only in the ventricle and ignores atrial events

22

Why use DVI over DDI

Patients with sick sinus syndrome where there's atrial sensing malfunction (oversensing) in which AV synchrony is desired.

23

Which type of lead commonly occurs with VDD pacing

single-pass lead which integrates an atrial-sensing electrode with a ventricular-pace/sense electrode

24

If DR pacemaker senses well however has high A- threshold, what mode can be used

VDD will maximize battery life

25

in VDD mode if the atrial rate drops below the LRL - what mode will it look like

VVI

There is no atrial LRL as it is a sensed channel only, if the atrial rate drops below the ventricular LRL, the ventricular clock will time out and will VP at the base rate, asynchronous with the slower atrial intrinsic rate

26

What are the 5 types of VDD floating leads

Unipolar
Bipolar (Narrow spacing)
Bipolar (Wide spacing)
Orthogonal
Diagonal bipolar half ring

27

What is the purpose of blanking periods

To prevent crosstalk

28

What two timing cycles are present in AAI

AB
ARP

29

What can reset the timing cycle giving a longer RR interval than expected in AAI

FFRWS

30

What two timing cycles are present in VVI

VB
VRP

31

What is the purpose of PVARP

Prevent tracking of retrograde P waves

32

What 3 modes have PVARP

DDD, VDD, DDI

33

What is the programmable range of PVAB

12-125ms

34

Define crosstalk window

ventricular-sensing amplifier during the AVI immediately after the PAVB

35

What happens if activity sensed in crosstalk window

triggered rather than inhibited pacing.

36

What is the range for ventricular safety pacing

AVI of 100-120ms

(programmable 50-150ms in some devices)

37

What should one suspect if AVI is shorter than programmed

Crosstalk

38

Give 4 ways to eliminate crosstalk

Turn on any anti-cross talk algorithms
Increase/extend the PAVB (best answer)
Decrease the atrial output (unlikely answer)
Reduce the ventricular sensitivity (also unlikely answer)

39

Define competitive atrial pacing

The triggering of an atrial tachyarrhythmia by an atrial pacing stimulus that falls within the atrium’s vulnerable period

40

What is NCAP and what can it be programmed between

A sensed atrial event in the PVARP starts a NCAP period during which no atrial pacing can be delivered

Programmable between 200-400ms

41

Define the ASW - Atrial sensing window

The portion of the RR cycle that is not part of the PVARP or AVI.

42

LRL never violated in V-based timing - TRUE/FALSE

True - its impossible

43

LRL never violated in A-based timing - TRUE/FALSE

FALSE - AA LRL will be reset by a sensed ventricular event within the VAI

This function mimics the compensatory pause commonly seen in normal sinus rhythm with ventricular ectopy.

44

MSR never violated in V-based timing - TRUE/FALSE

False - the effective atrial-paced rate theoretically may be considerably higher than the programmed max sensor rate if AR conduction is present.

45

Hybrid based timing is a combination of what

Atrial and ventricular based timing

46

Hybrid based timing uses predominantly what style of timing

Atrial based - till a loss of AV conduction occurs (then ventricular)

47

If the MTR interval has not yet been completed at the end of the AVI, what happens?

Ventricular pacing is withheld until the MTR interval ends

48

What is pseudo 1st degree AVB

a PV interval greater than the programmed sensed AV delay

49

Define fallback

Occurs automatically after mode switch, gradually decreasing pacing rate to ATR/VTR fallback LRL

50

Define fallback

Used to prevent a sudden rate drop when the atrial rate exceeds the URL of the device

Occurs automatically after mode switch, gradually decreasing pacing rate to ATR/VTR fallback LRL

51

Define rate smoothing and how does it work

Used to minimise variations in RR intervals/regularise ventricular rhythm

Uses the most recent RR interval (whether intrinsic or paced) to calculate an allowable increase or decrease in cycle length based on programmable rate smoothing percentage.

52

Is rate smoothing the same as Atrial and Ventricular Rate Stabilization

Yes - however stabilisation only runs off PVCs

53

What is the purpose of Atrial and Ventricular rate stabilization

Intend to eliminate long pauses after PAC or PVC, respectively.

54

What is the magnet rate for Boston devices

BOL = 100

ERI = 90

EOL = 85

55

What is the magnet rate for Medtronic devices

BOL = 85

ERI = 65

56

What is the magnet rate for St Jude devices

BOL = 100

EOL = 85

57

Is the magnet rates the same for Boston and St Jude devices?

Yes

58

How to calculate AEI

LRL minus AV interval

60bpm = 1000

PAV = 150

AEI = 850 = 70bpm (NEVER VIOLATED IN A-Based timing)