CIEDs

Question 1

CT and MRI can both interfere with ICD function

Answer 1

true

CTs can cause oversensing

MRIs not sufficient evidence. Manufacturers may list conditional circumstances when to perform. Most centers will not do MRI

Question 2

imaging can help identify the device when it is not known

Answer 2

true

Question 3

Indications for CIED

Answer 3

bradycardia
Sinus node disease
long QT
HCM
Dilated cardiomyopathy -  3chambers (RA and both ventricles)

Question 4

Subcutaneous ICD

Answer 4

larger than transvenous models
no antitachy functions or sustained antibrady functions
higher defib threshold

Question 5

CIEDs respond to low-amplitude electrical signals nd can be altered by extraneous signals such as:

Answer 5

electrocautery
RFI ablation
MRIs
Radiation therapy
lithotripsy

Question 6

Unipolar leads

Answer 6

more easily effected since the + and - ends are further from each other

Question 7

Bipolar leads

Answer 7

most modern PM

better shielding of lead ends reduces risk of interference

Question 8

PM code

1st letter

Answer 8

denotes cardiac chamber being paced
Atrium
Ventricle
Dual

Question 9

PM code

2nd letter

Answer 9

cardia chamber for electrical activity being sensed 
A
V
D
0 - none

Question 10

PM code

3rd letter

Answer 10

Response to sensed signal
0-none
I - inhibition
T - triggering
D - dual inhibition and triggering

Question 11

PM code

4th letter

Answer 11

Rate response features

Question 12

PM code

5th letter

Answer 12

denotes chambers in which multisite pacing is delivered

Question 13

Most common PM settings

Answer 13

AAI
VVI
DDD

Question 14

Ansynchronous pacing

Answer 14

simplest form
Modes are:
AOO
VOO
DOO 
meaning aria are paced with no sensing and no response since there is no sensing)

It can compete with pt’s intrinsic rate and depletes the battery life faster

Question 15

Single chamber pacing

Answer 15

can be atrial or ventricular

A-pacing requires the AV node and bundle of HIS to be intact (AAI).

Those with AV node disease can have a single chamber ventricular pm (VVI). senses the R wave, and if present, the PM discharge in inhibited

Question 16

PM syndrome

Answer 16

can occur with VVI from loss of AV synchrony
symptoms are syncope, PNS, orthopnea, hypotension, pulmonary edema

changing settings to DDD can relieve this

Question 17

DDD

Answer 17

more common methods when the SA or AV node is diseased

physologica pacing since it retains AV synchrony

there is a lead in the RA and one in the RV

If the atria is sensed, then the atrial pacer is nin habited

If the ventricle is sensed, the nteh ventricles is inhibited

This mode allows the SA node ot increase rate with exercise

Question 18

DDI

Answer 18

there is atrial and ventricular sensing but only responds t]wit inhibition

only used when there are tachy dysrhythmias

Question 19

Rate adaptive PM

Answer 19

can be used in pts who don’t have appropriate HR responses during exercise

BB, CCB or sick sinus common causes

Question 20

ICDs

Answer 20

include a pacing and shocking function to manage brady or tachy arrhythmias

Senses the R-R interval
-short intervals interpreted as tachy

RV lead to sense ventricular depolarization -
if Vfib sensed, a second waveform analysis occurs
-10 to 15 sec delay
-pt may lose conciousness

Question 21

ICD modes

1st letter

Answer 21

chamber shocked
O-none
A
V
D

Question 22

ICD modes

2nd letter

Answer 22

Anti-tachy pacing chamber
O
A
V
D

Question 23

ICD modes

3rd letter

Answer 23

Tachycardia detection mechanism
E - electrogram
H - hemodynamic

Question 24

ICD modes

4th letter

Answer 24

Anti-bradycardia pacing chamber
O
A
V
D

Question 25

CRT

Answer 25

used for CHF pts caused from asynchrony and conduction blocks Using 3 pacing leads in the RA, RV, coronary sinus, the device can be programmed to resynchronize the heart indications are EF <35%, QRS prolongation, NYHA 3 or 4

Question 26

ICDS/surgery

Answer 26

Timely interrogation pre-operatively (ASA recommends 3 months prior, others say 12 months) Re-programming preferred vs magnet Pad placed so current heads away from device bi-polar cautery current 5 cm from pacer leads Post-op interrogation *anti-tachycardic functions and rate response functions are usually suspended just before surgery if any EMI is possible

Question 27

Pacer insertion

Answer 27

under conscious sedation or MAC routine monitoring pt supine with head turned away from operative side anti-arrhythmic drugs available

Question 28

complications from pacer insertion

Answer 28

pnemo/hemo thorax air embolism *tension pneumo suspected if pt suddenly deteriorates in PEA cannulation of subclavian artery

Question 29

Factors that can increase depolarization threshold of PM

Answer 29

``` hyperkalemia acidosis antidysrhythmic meds hypoxia hypoglycemia local anesthetics MI hypothermia ```

Question 30

Factors that can decrease depolarization threshold of PM

Answer 30

``` hypokalemia increased catecholamine levels sympathomimetic drugs anticholinergics glucocorticoids stress/anxiety hyperthyroidism hypermetabolic state ```

Question 31

Magnets and surgery

Answer 31

Magnet response is not standardized not intended to treat PM emergencies or prevent EMI effects incorporated to allow for assessment of battery life and pacing threshold Placing a magnet over a generator may produce no change at all bc not al PM switch to asynchronous mode. Some may only go into asynchronous temporarily Those that do - have HR btwn 85-100 Some will have loss of pacing or transition into continuous pacing Need to know what happens when you put a magnet on the device

Question 32

Pts with CIED will have one of the following:

Answer 32

sustained or intermittent brady or tachy arrhythmia | heart failure

Question 33

Asynchronous mode is used why?

Answer 33

to prevent inappropriate oversensing

Question 34

Harmonic scalpels

Answer 34

US | used w/o concern for EMI

Question 35

Temporary PM

Answer 35

common after cardiac surgery Transvenous pacing is the most reliable temporary PM means PACs sometimes have a pacing function Transcutaneous is quickest emergent pacing modality -

Question 36

transcutaneous pacing

Answer 36

V3 and posteriorly at inferior scapula. Captures the RV then activates the LV. Maintained at 5-10 mA above capture threshold as tolerated