Cardiac rhythm monitors & equipment 5

Question 1

Using a magnet with a pacemaker

Answer 1

usually (but not always) converts the pacemaker to asynchronous mode

Question 2

Using a magnet with an ICD

Answer 2

suspends the ICD and prevents shock delivery

Question 3

Using a magnet with a pacemaker + ICD

Answer 3

suspends the ICD and prevents shock delivery; it has no effect on the pacemaker function

Question 4

_____________- occurs when the pacemaker delivers an electrical stimulus but fails to trigger myocardial depolarization

Answer 4

Failure to capture

Question 5

The following can impair pacemaker performance

Answer 5

electromagnetic interference or conditions that make the myocardium more resistance to depolarization (hyper or hypokalemia, hypocapnia, hypothermia)

Question 6

If surgical electrocautery is used with a pacemaker, the best option is for the surgeon to use

Answer 6

a bipolar device

Question 7

_________________ is typically contraindicated for the patient with a pacemaker or ICD, although some newer devices may be compatible.

Answer 7

MRI

Question 8

The most critical information to have preoperatively for a patient with a pacemaker is the patient’s

Answer 8

underlying rhythm so you know how to prepare for device failure

Question 9

Pacemaker failure can be treated with

Answer 9

isoproterenol, epinephrine, or atropine (it depends on the underlying rhythm)

Question 10

Pacemakers can malfunction in several ways:

Answer 10

failure to sense (under sensing)
failure to capture
failure to output

Question 11

Undersensing results in

Answer 11

asynchronous pacing

Question 12

____________ occurs when the pacemaker does not sense the underlying cardiac rhythm

Answer 12

Failure to sense

Question 13

Causes of failure to capture include

Answer 13

electrode displacement
wire fracture
and conditions that make the myocardium more resistant to depolarization

Question 14

Conditions that make the myocardium more resistant to depolarization include

Answer 14

hyper & hypokalemia
hypocapnia (intracellular K+ shift)
hypothermia
myocardial infarction
fibrotic tissue buildup around the pacing leads
antiarrhythmic medications

Question 15

___________ occurs when a pacing stimulus is not produced in a situation when it should be produced

Answer 15

Failure to output

Question 16

Failure to output can be caused by

Answer 16

oversensing
pulse generator failure
lead failure

Question 17

The risk of EMI is greatest with the use of

Answer 17

electrocautery and radiofrequency ablation

Question 18

When electrocautery is used, the __________ setting causes more EMI than the __________- setting

Answer 18

“coagulation”; “cutting”

Question 19

A__________- cautery causes more EMI than _____________ or _______________

Answer 19

monopolar cautery; bipolar or ultrasonic harmonic scalpel

Question 20

If the surgeon insists on monopolar cautery, then you insist that s/he uses

Answer 20

short bursts (<0.5 seconds)

Question 21

The risk of EMI is highest when the electrocautery tip is used within

Answer 21

a 15 cm radius of the pulse generator

Question 22

The electrocautery return pad should be placed

Answer 22

far away from the pulse generator & in a location the prevents a direct line of current through the pulse generator

Question 23

The following are NOT contraindications for patients with a pacemaker or ICD

Answer 23

lithotripsy
ECT