Optimizing ICD programming for shock reduction.

With the increasing numbers of patients with implantable cardioverter/defibrillators for primary prevention (PP), the topic of inappropriate therapy becomes more and more important. If a shock intervention, e.g. for rapidly conducted atrial fibrillation or fast VT (FVT), represents the first reminder of the implantable cardioverter/defibrillator (ICD), the adherence to the therapy will decrease. Moreover, anxiety to receive the next inappropriate ICD Rx is able to initiate a bad quality of life or depression. Starting with the PainFREE Rx II Trial results, the programming of antitachycardia pacing was able to terminate even fast ventricular arrhythmia, i.e. ≥ 188 bpm, in three of four episodes. Thereafter, several studies evaluated whether a prolongation in ventricular tachyarrhythmia (VT) detection is able to reduce unnecessary ICD Rx owing to nonsustained VT. The PREPARE trial evaluated this concept in a cohort of PP patients. This nonrandomized study compared a historical control group to patients with a prolonged detection interval. The results underline the idea that an extension in detection time leads to a significant decrease in ICD Rx for supra- as well as VT. The RELEVANT study investigated in a randomized fashion the outcome of an increase in detection time in nonischemic patients under CRT including an ICD. The findings clearly demonstrated a reduction in ICD Rx as well as hospital admissions, significantly. Currently, the ADVANCE III trial investigates a 30/40 interval detection compared to 18/24 for FVT in prospective randomized fashion in patients for primary or secondary prevention including all ICD devices.