Considerations for ventricular fibrillation detection by implantable cardioverter defibrillators

Implantable cardioverter defibrillator detection of ventricular fibrillation is inherently a complicated process. Nevertheless, there is a clinical imperative that ventricular fibrillation be detected with 100% sensitivity. Incumbent with the need for such a high sensitivity is a trade-off that results in diminished ventricular fibrillation detection specificity, which in turn results in unnecessary delivery of high-energy shocks. In this review we look in generic terms at the different lead and detection systems available and the effect of these systems on both undersensing and oversensing of ventricular fibrillation. In addition, several clinical and programming issues that affect sensitivity and specificity of ventricular fibrillation detection are reviewed.