CIEDs

Pacemakers (PPM)¶

• Used to maintain heart rate
• Indications
  • Complete AV block unless 2/2 MI or reversible cause
  • Symptomatic Sinus Bradycardia (HR <40 usually)
  • Symptomatic chronotropic incompetence (Inability to achieve 85% of age-predicted maximum HR)
  • Advanced 2^nd Degree AV Block (Block of ≥2 consecutive P waves)
  • Mobitz type II 2^nd Degree AV Block (Symptomatic or Asymptomatic)
  • Mobitz type I 2^nd Degree AV Block (Symptomatic only)
  • Afib w/bradycardia and pauses >5s
• Consists of a Pulse Generator (battery) and circuitry with 1,2, or 3 leads
  • Single chamber (1 lead) in RA or RV
  • Dual Chamber (2 leads) in RA and RV
  • Biventricular (3 leads) in RA, RV, and Cardiac Vein (to pace LV)
    • AKA cardiac resynchronization devices
• PG is implanted in infraclavicular region
• Malfunction or lead movement: High pacemaker lead thresholds

Implantable Cardioverter-Defibrillator (ICD)¶

• Primary or Secondary prevention of SCD from VT/VF
  • Indicated for prevention of sudden cardiac death (SCD)
• Primary Prevention
  • Prior MI and LVEF ≤30%
    • ≥40 days after MI and 3 months post PCI/CABG with an EF ≤30%
  • ICM/NICM w/NYHA Class II or III symptoms and LVEF ≤35% on GDMT
    • Wait for 3 months after initiation of GMDT to assess potential recovery
• Secondary Prevention
  • Prior VF or unstable VT without reversible cause
    • In patients with a FH of cardiac arrest or sustained, spontaneous VT
    • Survivors of cardiac arrest resulting from VF or VT not explained by a reversible cause
    • Syncope and sustained VT/VF on EP Study
    • Brugada syndrome with syncope or ventricular arrhythmia
    • Inherited Long QT syndrome not responding to β-blockers
  • Prior sustained VT with underlying cardiomyopathy
    • Sustained VT in the presence of structural heart disease
• Hypertrophic Cardiomyopathy if:
  • Primary Prevention
    • FH of SCD
    • Syncope (recurrent and/or associated with exertion)
    • Non-sustained VT on Holter
    • Hypotensive BP response to exercise
    • Extreme LVH (>3cm max septal wall thickness)
  • Secondary
    • Survivors of cardiac arrest
    • Sustained spontaneous ventricular Arrhythmias

Cardiac Resynchronization Therapy (CRT)¶

• Cardiac resynchronization therapy and QRS duration: systematic review, meta-analysis, and meta-regression
• Extra wire (3^rd wire) in the coronary sinus for synchronizing RV/LV
  • LV pacing in LBBB
  • Improves exercise tolerance, reduce the need for hospitalization, decrease overall mortality
• Indications
  • LVEF ≤35% + Sinus rhythm + One:
    • QRS ≥150ms and NYHA Class III-IV on optimal medical therapy (IA)
    • QRS >120ms but <150ms and NYHA Class III-IV symptoms on optimal medical therapy (optional)
    • NYHA Class I or II symptoms on optimal medical therapy undergoing pacemaker or ICD with anticipated frequent ventricular pacing
    • Indications of Cardiac Resynchronization in Non-Left Bundle Branch Block: Clinical Review of Available Evidence
  • LVEF ≤30%, QRS ≥150ms with LBBB, and NYHA Class I-II symptoms on optimal medical therapy
• CRT-P: No ICD, aka BiV
• CRT-D: ICD, aka BiV-ICD or Combo device

Implantable Loop Recorder (ILR)¶

• Continuous heart rhythm monitoring
• Use: Very rare events (>30 days apart)

Implantable Cardiovascular Monitor (ICM)¶

• Intravascular hemodynamic monitoring
  • Pulmonary Artery Pressure Sensors
    • CHAMPION Trial: decrease hospitalizations in NHYA III