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NICE guidance - implantable cardioverter defibrillators

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

NICE guidance has stated which patients should be considered for the use of implantable cardioverter defibrillators (ICD) include (1):

Implantable cardioverter defibrillators (ICDs) are recommended as options for:

  • treating people with previous serious ventricular arrhythmia, that is, people who, without a treatable cause:

    • have survived a cardiac arrest caused by either ventricular tachycardia (VT) or ventricular fibrillation or

    • have spontaneous sustained VT causing syncope or significant haemodynamic compromise or

    • have sustained VT without syncope or cardiac arrest, and also have an associated reduction in left ventricular ejection fraction (LVEF) of 35% or less but their symptoms are no worse than class III of the New York Heart Association (NYHA) functional classification of heart failure

  • treating people who:

    • have a familial cardiac condition with a high risk of sudden death, such as long QT syndrome, hypertrophic cardiomyopathy, Brugada syndrome or arrhythmogenic right ventricular dysplasia or

    • have undergone surgical repair of congenital heart disease

Implantable cardioverter defibrillators (ICDs), cardiac resynchronisation therapy (CRT) with defibrillator (CRT-D) or CRT with pacing (CRT-P) are recommended as treatment options for people with heart failure who have left ventricular dysfunction with a left ventricular ejection fraction (LVEF) of 35% or less as specified in table below:

  • Treatment options with ICD or CRT for people with heart failure who have left ventricular dysfunction with an LVEF of 35% or less (according to NYHA class, QRS duration and presence of LBBB)

QRS interval

NYA class I

NYA class II

NYA class III

NYA class IV

<120 milliseconds

ICD if there is a high risk of sudden cardiac death

ICD if there is a high risk of sudden cardiac death

ICD if there is a high risk of sudden cardiac death

ICD and CRT not clinically indicated

120- 149 milliseconds without LBBB





120-149 milliseconds with LBBB





>=150 milliseconds with or without LBBB





LBBB, left bundle branch block; NYHA, New York Heart Association

The NICE guidance does not cover the use of implantable defibrillators for non-ischaemic dilated cardiomyopathy.


  • subcutaneous implantable cardioverter defibrillator (2)
    • current evidence on the efficacy of the insertion of a subcutaneous implantable cardioverter defibrillator (ICD) for the prevention of sudden cardiac death in the short and medium term is adequate

    • an entirely subcutaneous ICD differs from a conventional ICD in that the lead is placed subcutaneously, rather than transvenously
      • the lead comprises 2 sensing electrodes and a shocking coil
      • the ICD senses cardiac signals, but the lead is not directly attached to the heart
      • unlike a conventional ICD, the subcutaneous device is not designed to provide long-term pacing


  1. NICE (June 2014). Implantable cardioverter defibrillators and cardiac resynchronisation therapy for arrhythmias and heart failure
  2. NICE (April 2013). Insertion of a subcutaneous implantable cardioverter defibrillator for prevention of sudden cardiac death.

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