70. Implantable cardiac devices

Question 1

5 indications for permanent pacemaker

Answer 1

1. 3rd deg and advances 2nd deg heart block
2. Symptomatic brady from any type of 2nd degree block
3. ASx, persistent 3rd degress block with rate > 40
4. Chronic bifasicular or trifasicular block with intermttentn3rd or adv 2nd degree block
5. 2nd or 3rd deg block with excerise in absence of ischemia

Question 2

4 indications for defib implant

Answer 2

1. Arrest from VF or VT from non-tranient event
2. spontaneous sustained VT
3. syncope of undetermined orogin with VT or VF
4. non-sustained VT inCAD, prior MI

Question 3

5 letter codes of pacers

Answer 3

1. Chamber paced
2. Chamber sensed
3. Sense response
   - trigger
   - inhib
   - dual
4. Programmability
5. Antitachycardia function
   - pace
   - defib
   - dual

Question 4

Complications of implant

Answer 4

• 2% have wound infection
• 1% have sepsis
• Most cases need reimplantation
• Pain and local inflammation
• Blood Cx if concerned
• Staph and strep most common
• Vanco

Question 5

Def pacemaker syndrome

Answer 5

• May have worsening of Sx that caused implantation
• Due to loss of AV synchrony
  o Most common in VVI
  o Due to contraction of atria against closed valve
• Can elevate BNP in severe form
• 20% of patients
  o Most get used to it

Question 6

3 main types of pacer malfunction

Answer 6

o Fail to capture
o Inappropriate sensing
o Inappropriate pacing rate

Question 7

Causes of failure to capture

Answer 7

Complete loss of spikes may be due to battery loss
Most commonly a lead problem
	Displacement
	Break
Exit block
	Failure to depolarize 
	Changes in endocardium

Question 8

Causes of inapproriate sensing

Answer 8

Undersense
	Complete or intermittent
	Progressive fibrosis after
	May or may not be followed by spike
Oversense
	Detects signal that is not cardiac in origin
	Pectoral muscles
	Electrocautery

Question 9

Causes of inappropriate rate

Answer 9

o below rate in battery depletion

o rare to have runaway rate

Question 10

2 main tests to order to look at pacer

Answer 10

CXR

ECG

Question 11

Causes of defib malfunction

Answer 11

• increase in VF/VT freq
• displaced lead
• recurrent non-sustained VT
• sense and shock of SVTs
• oversense T waves
• sense non-cardiac signals
• recurrent VT with low shock strength
• HD significant SVTs

Question 12

indication for biventricular pacing

Answer 12

L side HF

Question 13

3 main types of cardiac assist devices

Answer 13

o LVAD
o BiVAD
o TAH (total artificial heart)

Question 14

Possible complications with assist devices

Answer 14

• driveline infection
• bleeds due to anticoag
• shock or hypoperfusion
• dysrthmias

Question 15

MGMT of pumps dysfunction

Answer 15

• CPR risks dislodging cannula and massive hemorrhage
• Try to correct pump dysfunction
• May have hand pump