The Particulars: Programming long arrhythmia detection times has been shown to reduce the incidence of implantable cardioverter-defibrillator (ICD) shock therapy. However, data are lacking on the impact of prolonged arrhythmia detection times on the rates of ICD shock therapy and other adverse outcomes.

Data Breakdown: Four studies were reviewed for a meta-analysis that examined the impact of programming longer versus shorter ICD arrhythmia detection times on clinical outcomes. Of the nearly 5,000 patients involved in the meta-analysis, there were 305 mortalities, 1,284 total shocks, 658 appropriate shocks, and 114 syncopal episodes during a mean/median follow-up of 12 to 17 months. Significant reductions in mortality, total shocks, appropriate shocks, and inappropriate shocks—without a significant increase in syncope—were observed in patients with long detection times when compared with those with shorter times.

Take Home Pearl: The use of long arrhythmia detection times appears to significantly decrease the burden of shock therapy and mortality without significantly increasing syncope rates among ICD recipients.