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Pacemakers and ICD's

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					Pacemakers and Implantable
 Cardioverter Defibrillators
    Dr. Sivaraman Yegya-Raman
    Temporary and Permanent Cardiac Pacing
• Introduction
• Temporary pacing : Indications, Technique
• Permanent Pacing :
        Nomenclature
        Indications
        Pacing for Hemodynamic Improvement
        Pacemaker Implantation, Complications

•    Implantable Cardioverter Defibrillator
Temporary Cardiac Pacing

• Transvenous
• Transcutaneous
• Epicardial
• Transesophageal
 Indications for Temporary Pacing
 Acute myocardial infarction with:
    CHB, Mobitz type 2 AV block, medically
  refractory symptomatic bradycardia,
  alternating BBB, new bifascicular block, new
  BBB with anterior MI
 In absence of acute MI : SSS, CHB, Mobitz
  type 2 AV block
 Treatment of tachyarrhythmias : VT
Temporary Transvenous Pacing
        Electrograms
Permanent Pacing
      The Pacemaker System
• Patient
 Lead                       Lead
 Pacemaker
• Programmer
                              Pacemaker
       Pacemaker Implantation

• Transvenous :
     • Generator implanted anterior to pectoral muscle
     • Atrial/Ventricular leads via subclavian or cephalic
       vein
     • Sensing and pacing threshold
     • Chest X-ray for pneumothorax, lead position
Castle LW, Cook S: Pacemaker radiography. In Ellenbogen KA, Kay GN, Wilkoff BL [eds]: Clinical Cardiac Pacing. Philadelphia, WB Saunders, 1995, p 538.
  Acute Complications of Pacemaker
           Implantation
• Venous access
   Pneumothorax, hemothorax
   Air embolism
   Perforation of central vein
   Inadvertent arterial entry

• Lead placement
   Brady – tachyarrhythmia
   Perforation of heart, vein
   Damage to heart valve

• Generator
   Pocket hematoma
   Improper or inadequate connection of lead
Delayed Complications of Pacemaker Therapy
  • Lead-related
     Thrombosis/embolization
     SVC obstruction
     Lead dislodgement
     Infection
     Lead failure
     Perforation, pericarditis

  • Generator-related
     Pain
     Erosion, infection
     Migration
     Damage from radiation, electric shock

  • Patient-related
     Twiddler syndrome
  Codes Describing Pacemaker Modes

  Position          1             2              3               4           5


 Function      Chambers      Chambers      Response         Rate       Multisite
               Paced         Sensed        to Sensing       Modulation pacing


  Specific     O=none        O=none        O=none           O=none       O=none
               A=Atrium      A=Atrium      T=Triggered      R=Rate       A=Atrium
Designations   V=Ventricle   V=Ventricle   I=Inhibited      modulation   V=Ventricle
               D=Dual-       D=Dual-       D=Dual-                       D=Dual-
               Atrium and    Atrium and    Triggered and                 Atrium and
               Ventricle     Ventricle     Inhibited                     Ventricle


                                                           NASPE/BPEG 2002
DDD
    Indications for Pacing for AV Block
Degree   Pacemaker necessary                 Pacemaker          Pacemaker not
                                             probably           necessary
                                             necessary
Third    Symptomatic congenital
         complete heart block
         Aquired symptomatic complete
         heart block
         Atrial fibrillation with complete
         heart block
         Acquired asymptomatic
         complete heart block
Second   Symptomatic type I                  Asymptomatic        Asymptomatic type
         Symptomatic type II                 type II             I at supra-His (AV
                                             Asymptomatic        nodal) block
                                             type I at intra-His
                                             or infra-His levels
First                                                           Asymptomatic or
                                                                symptomatic
    Indications for Pacing for Sinus Node Dysfunction
Pacemaker                  Pacemaker probably         Pacemaker not
                           necessary                  necessary



Symptomatic bradycardia    Symptomatic patients       Asymptomatic sinus node
                           with sinus node            dysfunction
                           dysfunction with
                           documented rates of <40
                           bpm without a clear-cut
                           association between
                           significant symptoms and
                           the bradycardia
Symptomatic sinus
bradycardia due to long-
term drug therapy of a
type and dose for which
there is no accepted
alternative
                  Case #1
 72 year old male with chronic atrial
fibrillation of greater than 10 years’ duration is
admitted following a syncopal episode. A 2D
echo shows LVEF 60%. Telemetry reveals atrial
fibrillation with slow ventricular response and
pauses of 5 to 6 seconds associated with
lightheadedness.
    How would you proceed?
                   Case #1
 72 year old male with chronic atrial fibrillation of
greater than 10 years’ duration is admitted
following a syncopal episode. A 2D echo shows
markedly dilated left atrium and LVEF 60%.
Telemetry reveals atrial fibrillation with slow
ventricular response and pauses of 5 to 6 seconds
associated with near syncope.
    How would you proceed?

Answer: Implant a ventricular rate responsive
pacemaker
         Pacemaker Follow-up
• GOAL OF FOLLOW-UP
  – Verify appropriate pacemaker operation
  – Optimize pacemaker functions
  – Document findings, changes and final settings in
    order to provide appropriate patient management
         “Pacemaker Syndrome”
• Fatigue, dizziness, hypotension
• Caused by pacing the ventricle asynchronously,
  resulting in AV dissociation or VA conduction
• Mechanism: atrial contraction against a closed AV
  valve and release of atrial natriuretic peptide
• Worsened by increasing the ventricular pacing rate,
  relieved by lowering the pacing rate or upgrading to
  dual chamber system
• Therapy with fludrocortisone/volume expansion NOT
  helpful
 Sources of Electromagnetic Interference

• Medical                       • Nonmedical
  – MRI                           – Arc welding
  – Lithotripsy                     equipment
  – Electrocautery/cryosurger     – Automobile engines
    y                             – Radar Transmitters
  – External defibrillators
  – Therapeutic radiation
Biventricular Pacing
    Normal Conduction Is Important
                   • Normal conduction
Sinus
                     allows for prompt
node
                     and synchronous
                     activation of the
  AV                 atria and ventricles
  node             • Results in a brief P
                     wave, PR interval
                     and a narrow QRS
Cardiomyopathy, LBBB, Heart Failure


Sinus node         • Delayed lateral wall
                     contraction
                   • Disorganized ventricular
                     contraction
                   • Decreased pumping
AV                   efficiency
node

 Conduction
 block
                    Heart Failure
              Bifocal Ventricular Pacing

Sinus node                          • Intraventricular Activation
                                    • Organized ventricular
                                      activation sequence
                                    • Coordinated septal and
                                      free-wall contraction
AV                                  • Improved pumping
node                                  efficiency

 Conduction
 block                Stimulation
                      therapy
       Bi-Ventricular Pacing

Right atrial lead


                         Coronary sinus lead




Right ventricular lead
                                 N Engl J Med 2003
SVC coil




RA lead              LV lead



           RV coil
  RA lead




            LV lead
RV lead
Bi-V Pace
Implantable Cardioverter Defibrillator
               (ICD)
            ICD Implantation
• Secondary prevention: Prevention of SCD in
  patients with prior VF or sustained VT.
• Primary prevention: Prevention of SCD in
  individuals without a h/o VF or sustained VT.
          Indications For ICD
• VF/sustained unstable VT not in the setting of a
  completely reversible cause.
• LVEF ≤ 35%, CHF NYHA class II, III.
• Ischemic dilated cardiomyopathy, LVEF ≤ 40%, NSVT
  and inducible sustained VT.
• Syncope, LV dysfunction, inducible sustained VT.
• High risk patients with: hypertrophic
  cardiomyopathy, LQT syndrome, RV dysplasia,
  Brugada syndrome
Ellenbogen K A, 2007
ACC/AHA/HRS 2008 Guidelines: Systolic Heart Failure -
     Cardiac Resynchronization Therapy (CRT)
                Recommendations

     • LVEF ≤ 35%
     • QRS ≥ 120 msec
     • NYHA functional Class III or
       ambulatory Class IV
     • Optimal medical therapy
                “Typical Case”
  58 year old male, CAD, prior MI, EF 28%, CHF, NYHA
  class II, Medications: Furosemide 40 mg, Enalapril 20
  BID, Aldactone 25 qd, Carvedilol 25 BID, no syncope
  or VT, ECG: Sinus rhythm, old anteroseptal MI, QRS
  92 msec

Based on available trial data, you would suggest:
   A. Treating medically without device implantation
   B. Implanting an ICD
   C. Implanting an ICD with biventricular pacing
   capabilities (3 leads)
             Typical Case

Q: 60 year old female presents with a 1
year h/o non ischemic dilated
cardiomyopathy, CHF NYHA class III
despite maximum medical therapy, LVEF
20% and LBBB with QRS 170 msec. What
device is indicated?

A: Bi-Ventricular ICD
1° Prevention: Clinical Device Algorithm
 If Non –Ischemic Dilated Cardiomyopathy:
                       & EF ≤ 35%


             ACE inhibitors, Beta Blockers


                           ICD



       If LVEF ≤ 35%, CHF Class III-IV, QRS ≥ 120 ms



                         BiV ICD
  Magnet Application on Pacemaker/ICD

• Pacemaker:
  – Disables sensing
  – Changes to VOO or DOO mode
  – Useful if cautery is being used in PPM dependent pt.
• ICD:
  – Disables Tachycardia sensing
  – Useful at bedside if pt. has ventricular lead fracture or Afib
    with rapid ventricular response causing ICD shocks
  – Prevents ICD shock during cautery application at surgery
       Future Directions
• Leadless pacing
• Biological pacemakers
• Subcutaneous ICD

				
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