Implantable Cardiac Devices

Question 1

Who was responsible for the first external pacemaker?

Answer 1

Mark Lidwell, Albert Hyman

Question 2

What was created in 1957, and by whom?

Answer 2

Earl E. Bakken produced the first battery-operated wearable pacemaker

Question 3

What was introduced in the 2000s, and what benefit did it provide?

Answer 3

bi-ventricular pacing, paces both ventricles to go at the same time

Question 4

What visual cue represents an unfired beat from the temporary pacemaker?

Answer 4

a vertical dotted line

Question 5

What can happen if the sensitivity threshold on a temporary pacemaker is set too low?

Answer 5

ventricular fibrillation

Question 6

How do you know where to set sensitivity?

Answer 6

half of the

Question 7

What does VVI represent?

Answer 7

The ventricle is being paced, the ventricle is being sensed, the ventricular signal from the pacemaker is being inhibited.

Question 8

What does VAT represent?

Answer 8

The ventricle is being paced, the atria is being sensed, the (?) signal from the pacemaker is being triggered.

Question 9

What does DVI represent?

Answer 9

Both the atria and ventricles are being paced, the ventricle is being sensed, the ventricular signal from the pacemaker is being inhibited.

Question 10

What are some benefits of choosing a temporary transvenous pacemaker over a transcutaneous pacemaker?

Answer 10

more comfortable, will move around less (reduced likelihood of dislodging)

Question 11

What are the three main purposes of a permanent pacemaker?

Answer 11

• restore rhythm/function
• improve QoL
• less time in hospital

Question 12

What seven problems could a permanent pacemaker cause?

Answer 12

• systemic infection
• perforation
• tamponade
• mess with MRIs
• vascular occlusion
• cardiomyopathy cause by the pacemaker
• lead revision/extraction/device/replacement

Question 13

Which part of the unipolar-lead pacemaker is the anode?

Answer 13

the pulse generator

Question 14

How can you distinguish a unipolar-lead pacemaker from a bipolar-lead pacemaker?

Answer 14

bigger pacemaker spikes

Question 15

Where is the anode located in the bipolar lead pacemaker?

Answer 15

ring electrode

Question 16

What type of fixation involves screwing?

Answer 16

active

Question 17

What problems do using the subclavian vein in the transvenous insertion procedure have?

Answer 17

sharp angle within vein can compress and damage lead

Question 18

What does voltage represent?

Answer 18

the strength/amplitude of the pacing pulse

Question 19

What does current represent?

Answer 19

how fast the charge goes through the circuit

Question 20

What are the three main sources of resistance/impedance?

Answer 20

• the wire
• the tip of the pacemaking wires
• the cluster of ions where the cathode of the pacemaker meets the tissue of the heart

Question 21

What is a good range for impedance values to stay in ?

Answer 21

300 ohms - 3000 ohms

Question 22

Which electrical value is not directly controllable for a pacemaker?

Answer 22

current

Question 23

What is Ohm’s law?

Answer 23

I = V x R

Question 24

What will the ECG of a person who has a dual-chamber sensing pacemaker usually look like?

Answer 24

an ECG with NSR

Question 25

What is the purpose of the post-ventricular atrial refractory period?

Answer 25

prevent atria from responding erroneously (e.g. PACs, retrograde P-waves. far-field ventricular signals)

Question 26

What problems can come up with VDD pacing?

Answer 26

If the atrial rate falls below the LRL programmed in, AV synchrony will be lost, which can drain the battery faster.

Question 27

What can happen in DDI mode?

Answer 27

If the atrial rate becomes higher than the LRL, while the pacemaker is forcing the ventricles to beat at the LRL-set pace, so atria and ventricles stop working in tandem.

Question 28

What is DDI mode good for?

Answer 28

atrial tachyarrhythmias (e.g.) aFib, DDI mode won't let the ventricles try to keep up with an extremely high atrial rate

Question 29

How does the single chamber pacemaker decide how to act on the intrinsic rhythm?

Answer 29

if intrinsic rhythm>LRL--> pacemaker inhibited | if intrinsic rhythm

Question 30

How is VA calculated?

Answer 30

cycle length (60,000/HR) - AV delay length

Question 31

Why is cross talk a problem?

Answer 31

If the atria are being sensed when the ventricles are supposed to be sensed, the pacemaker will inhibit ventricular activity, even when it is needed.

Question 32

How is cross-talk prevented?

Answer 32

blanking periods

Question 33

What is the total atrial refractory period?

Answer 33

AV delay + PVARP The amount of time elapsed after impulse travels to AV node, and then the ventricles are allowed to repolarize

Question 34

How would loss of capture present on the ECG?

Answer 34

see spikes with no depolarization waves with it

Question 35

List examples of AV/refractory period-based pseudomalfunctions.

Answer 35

- ventricular safety pacing - managed ventricular pacing - blanking - rate-adaptive AV delay - auto PVARP - PVC response - noncompetitive atrial pacing - ventricular sense response pacing

Question 36

How would atrial oversensing present on the marker channel of a paced ECG?

Answer 36

The marker channel will have AS markers but the ECG will have no p-waves in the same area.

Question 37

Normal range of impedance values?

Answer 37

200-2000 ohms

Question 38

How is lower rate interval calculated?

Answer 38

60,000/bpm

Question 39

What does "slew rate" mean?

Answer 39

Slew rate represents how much the voltage changes over a period of time

Question 40

What are the 3 components of the implantable pulse generator?

Answer 40

1. battery 2. connectors 3. circuitry

Question 41

What does the first column of the universal code represent?

Answer 41

chamber that is being paced

Question 42

What are the 4 main indications for a pacemaker?

Answer 42

1. symptomatic bradycardia 2. sick sinus syndrome 3. CHB 4. chronotropic incompetence

Question 43

What 4 steps are part pf the pacemaker interrogation process?

Answer 43

1. check lead integrity 2. troubleshoot 3. check device usage 4. check battery life