Devices

Question 1

Nomenclature for ICDs?

Answer 1

Question 2

Nomenclature for Pacemakers?

Answer 2

Question 3

Steps to manage Pacemaker/ICDs?

Answer 3

1. Identify Device type, Manufacturer and Model
   
   2. Identify Indication
   3. Ensure at least 3 month battery life
   4. Most recent interrogation: Pacemaker q12 mo, ICD q6 months
   5. Determine Mode it is programmed in
   6. What is the Magnet response?
      a. Pacemakers: Asynchronous mode 80-100 bpm and turns off rate response
      b. ICDs - suspends tachytherapies
   7. Determine If Reprogramming Indicated.
      a. University Pacemaker Service: When not around may call the Cardiac Fellow?
      b. To Asynchronous mode for concern of EMI?
      i. Probably not needed if:
      1) Procedure below umbilicus or > 15 cm from device.
      2) Only Bipolar or harmonic scalpel will be used
      3) High concern for R on T phenomenon if put in Asynchronous mode
      ii. Probably needed if:
      1) Use of monopolar (Bovie), Radiofrequency Ablation, Argon beam coagulator, TENS and SCS will be used
      2) Surgery < 15 cm from leads/generator
      c. Rate change
      i. Depending on Hemodynamics of anticipated case
   8. When magnet may be used:
      a. Emergency situation when reprogramming not available
      b. Unforeseen EMI situation
      c. Consider use in ICD for cases to allow for taking the magnet back off to allow treatment of tachyarrythmias by the device but still have the team place the pacer function of the ICD into asynchronous mode. Only if reliable access to magnet during case. Otherwise pads.
   9. Ensure availability of Magnet/External defibrillation/pacing equipment
   10. Defib pads on for high risk patients who had an ICD turned off.
   11. Induction
       a. Consider avoiding succinylcholine given reports of muscle fasciculations have inhibited and oversensing problems. If going to use consider pretreatment with non-depolarizer
   12. After case must be programmed back

Question 4

CRT Indications?

Answer 4

• Symptomatic Heart Failure despite optimal medical therapy
  
  • LVEF < 35%
  • QRS duration >120 ms (LBBB)
    Crossover with defibrillator indications – CRT-D

Question 5

Lead placements for Pacemaker/ICD/CRT?

Answer 5

1. Right atrium - tip of lead is located in atrial appendage.
   
   2. Right ventricle - tip in apex.
   3. Left ventricle - lead through the coronary sinus ends in posterior cardiac vein, used for cardiac synchronization therapy in patients with bundle branch blocks.
      Epicardial - placed on ventricle mainly used in cardiac surgery.