Comparison of therapy detection times between implantable cardioverter defibrillators with standard dual- and single-chamber pacing

Previous implantable cardioverter defibrillators (ICDs) required patients in need of dual-chamber (DDD) pacing for improved hemodynamic status to undergo implantation of separate devices to treat bradycardia and/or ventricular arrhythmias. An investigation was conducted to verify the performance of a new ICD that combines both therapies. Sixty-nine patients at 17 European and Canadian centers were implanted with VENTAK AV models 1810/1815, ICD's that includes DDD pacing and algorithms designed to differentiate between atrial and ventricular arrhythmias. 36 of the cohort were compared to 32 patients tested at six centers with an external test device (VENTAK MINI). In both cohorts detection times were calculated for ventricular fibrillation (VF) induced at implant. The mean detection times (DT) from the VENTAK AV device were compared to the DT from the VENTAK MINI device. Patient characteristics of the VENTAK AV and the VENTAK MINI control groups were similar. Mean VF detection time (+/- SD) with the VENTAK AV device was 2.21 +/- 0.54 seconds, as compared with 1.87 +/- 0.62 seconds with the VENTAK MINI (p < 0.01), indicating that the difference in means did not exceed one second. The VENTAK AV system function did not demonstrate interaction with the pacemaker function, as indicated by the clinical significance with the detection times of the study device. The difference in detection times between cohorts did not statistically exceed one second. Appropriate detection of the new ICD was not compromised by the addition of the dual-chamber pacing therapy.