Managing the Patient with an AICD


Raja Selvaraj, JIPMER

What information do you need to manage the patient with an AICD?

  • What is an AICD ?
  • Managing ICD related issues
  • How does it affect day-to-day life
  • How does it affect medical management ?

What is an AICD


What is an AICD

  • A miniaturized battery powered device
  • Tracks the heart rate and rhythm
  • When there is a tachyarrhythmia, it attempts to correct the rhythm

What does it do?



What it is not

  • Does not improve the function of the heart
  • Not a treatment for ventricular tachycardia
  • Does not prevent tachy-arrhythmias

How does it differentiate an arrhythmia from normal rhythm

  • At simplest level, discrimination is rate based
  • Other clues are used
    • Relation of atrial and ventricular activity
    • Morphology of the electrogram


How does it correct the rhythm

  • By delivering a biphasic DC shock
  • By overdrive pacing

Follow up

  • Usually required every 6 months to a year
  • Device longevity is generally 5-10 years
  • After this needs to be changed (lead retained)

ICD issues

Shock from the device

  • Usually felt like a blow on the back / being punched in the chest
  • Patient perception varies
  • Phantom / inappropriate / appropriate shocks

Need for consultation at specialist center

  • One shock + feeling well - early elective device check
  • Immediate visit
    • More than one shock
    • Feeling unwell

Alert from device

  • Audible / vibratory alert
  • If no other issues, wait one day to confirm alarm (same time each day)
  • If repeat alarm, consult at specialist center

Patient who presents with repeated shocks

  • Determine if appropriate / inappropriate
  • Appropriate - treat arrhythmia
  • Inappropriate - may use strong magnet to inhibit therapies

Daily Life

Minimal impact on day to day life

  • Diet
  • Exercise
  • Pregnancy / delivery
  • Determined by underlying disease


  • Avoid driving public transport vehicles
  • 6 weeks after implantation - Primary prevention
  • 6 months without events - Secondary prevention



  • No interference from majority of household devices
  • Remote control / microwave / electric switches / Walk through scanners at airports
  • Mobile phones - 6 inches away - opposite ear / not in shirt pocket
  • Music players - headphones 6 inches away
  • Anti-theft systems - avoid leaning on / prolonged proximity
  • Avoid strong magnets

Suspect EMI

  • Shock / symptoms
  • Related to place / device
  • When in doubt - check in specialist center


Medical management


  • Most ailments can be treated as usual
  • Underlying disease dictates drugs that are safe to use
  • Anti-arrhythmic drugs may affect defibrillation threshold


  • CXR / ultrasound - safe
  • CT scan - Can sometimes be associated problems when device is directly in scanning field
  • MRI - MRI conditional devices - take specialist opinion

Radiotherapy for cancer

  • Can damage the device circuitry
  • Shield if possible
  • Move device if it is in the field


  • Extracorporeal shock wave lithotripsy - Avoid
  • Transcutaneous electrical nerve stimulation - Avoid on torso, rare interaction when used in limbs
  • Electro convulsive therapy - no EMI, but avoid inappropriate therapy for sinus tachycardia
  • External defibrillation - keep distance

Surgical procedures

  • Cautery can produce EMI
  • Bipolar cautery / short bursts / away from device
  • Magnet over device / deacivate device


  • AICD implants increasing in number
  • More such patients will be cared for by cardiologists / physicians
  • Many aspects of care related to underlying disease than the ICD
  • Understanding of basic aspects of AICD helps manage the patient