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    ICD Complications


    Last Updated Feb 17, 2022
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    By Julian Marsden, Aaron Chan


    • Common indications for placement of an implantable cardioverter-defibrillator (ICD) include VT/VF resulting in cardiac arrest, sustained VT in patient with structural heart disease, and end-stage cardiomyopathies with low ejection fraction, long QT syndrome, and Brugada syndrome.
    • Most common presentation is patient presenting to ED after an ICD shock.
    • More than 30% of patients with history of VT/VF receive an appropriate shock within two years of ICD implantation.
      • Common triggers include electrolyte imbalance, ischemia, heart failure, medication noncompliance, and recent change to antiarrhythmic medications.
    • Causes of inappropriate shocks include:
      • Dysrhythmias (most common) including AF, SVT, or sinus tachycardia.
      • Lead fracture, lead displacement or battery depletion.
      • T wave oversensing, QRS complex double-counting.
      • Interference from external electromagnetic radiation (metal detectors, MRI)
    • Causes of failure of ICD to deliver successful shock include:
      • Lead fracture, lead displacement, scar tissue or battery depletion.
      • Recent change to antiarrhythmic medications.
      • Electrolyte imbalance.
    • Other complications associated with ICD implantation include wound hematoma, site/lead infection, pericardial effusion, PTX, and upper extremity DVT/SVT syndrome.
    • Early diagnosis and treatment of ICD shocks will reduce psychological distress and improve quality of life in patients with ICDs.

    Diagnostic Process

    • Initial investigations in all patients presenting with single/multiple ICD shocks include cardiac monitoring, 12-lead ECG, basic labwork including extended electrolytes (particularly, K and Mg), TSH, and CXR to diagnose lead displacement/fracture.
      • If suspect ischemia, consider cardiac biomarkers +/- bedside echocardiography.
    • All patients presenting with multiple shocks will require early cardiology consult OR electrophysiology consult for device interrogation if directly available.


    • If inappropriate shocks due to dysrhythmia or suspected device malfunction, place magnet over ICD to disable defibrillator. Treat SVT accordingly with beta blockers/CCB.
    • If appropriate shocks are unsuccessful in correcting arrhythmia AND hemodynamically unstable, place defibrillator pads in anterior-posterior configuration at least 10cm from ICD, resuscitate according to ACLS protocols, and treat underlying cause.
      • If shockable rhythm not adequately treated by ICD, place magnet over device to deactivate if necessary.
      • If shockable rhythm treated by ICD but patient is in recurrent VT (storm), do not place magnet. These patients require acute management of underlying dysrhythmia.
      • These patients will require early consultation with cardiology and high-priority transfer to facility with cardiac/critical care unit.
    • Well-appearing, asymptomatic patient after single shock can be discharged home after arranging for follow-up with cardiologist and pacemaker clinic.

    Endocarditis / Device Infections

    • Pocket infection should be suspected in patient presenting with local inflammation, while lead infection may present with bacteremia +/- endocarditis.
      • Perform TTE, CXR and blood culturesx2 prior to empiric ABX in all patients with suspected ICD-related infection.
      • Start vancomycin 25mg/kg IV x1 loading dose, then 15mg/kg IV q8-12h.
      • Consult physician who inserted device for surgical removal.
      • Aspiration +/- culture of device pocket should be performed by experienced physician.

    Pericardial Effusion (Tamponade, Migration Lead)

    • Perform CXR and bedside echocardiography to confirm cardiac tamponade in patient with newly inserted cardiac device who presents with hypotension.

    Pocket Hematoma

    • For large pocket hematoma, consider consult for surgical evacuation. Do not perform needle aspiration.

    Quality Of Evidence?


    • Role of early device removal in cardiac device infection: Strong association with lower short and long-term mortality.
    • Duration of antimicrobial therapy following device extraction: Based largely on retrospective studies analyzing outcomes associated with common clinical practice.

    Further Resources

    Related Information

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