Do Traditional VT Zones Improve Outcome in Primary Prevention ICD Patients?

Autor: Duncan E, Thomas G, Johns N, Pfeffer C, Appanna G, Shah N, Hunter R, Finlay M, Schilling RJ, Sporton S
Zdroj: Pacing & Clinical Electrophysiology; Nov2010, Vol. 33 Issue 11, p1353-1358, 6p
Abstrakt: We reviewed outcomes in our primary prevention implantable cardioverter defibrillator ( ICD) population according to whether the device was programmed with a single ventricular fibrillation (VF) zone or with two zones including a ventricular tachycardia (VT) zone in addition to a VF zone. This retrospective study examined 137 patients with primary prevention ICDs implanted at our institution between 2004 and 2006. Device programming and events during follow-up were reviewed. Outcomes included all-cause mortality, time to first shock, and incidence of shocks. Eighty-seven ICDs were programmed with a single VF zone (mean >193 ± 1 beats per minute [bpm]) comprising shocks only. Fifty ICDs had two zones (mean VT zone >171 ± 2 bpm; VF zone >205 ± 2 bpm), comprising antitachycardia pacing (100%), shocks (96%), and supraventricular (SVT) discriminators (98%) . Discriminator 'time out' functions were disabled. Mean follow-up was 30 ± 0.5 months and similar in both groups. All-cause mortality (12.6% and 12.0%) and time to first shock were similar. However, the two-zone group received more shocks (32.0% vs 13.8% P = 0.01). Five of 16 shocks in these patients were inappropriate for SVT rhythms. The single-zone group had no inappropriate shocks for SVTs. Eighteen of 21 appropriate shocks were for ventricular arrhythmias at rates >200 bpm (three VF, 15 VT). This suggests that primary prevention ICD patients infrequently suffer ventricular arrhythmias at rates <200 bpm and that ATP may play a role in terminating rapid VTs. Patients with two-zone devices received more shocks without any mortality benefit. (PACE 2010; 1353-1358) [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index