Programming of Implantable Cardioverter-Defibrillators on the Basis of the Upper Limit of Vulnerability

Publisher Website
Google Scholar
Abstract
Background A patient-specific measure of defibrillation efficacy that requires a minimum number of ventricular fibrillation (VF) episodes would be valuable for programming implantable cardioverter-defibrillators (ICDs). The upper limit of vulnerability (ULV) is the weakest shock strength at or above which VF is not induced when a stimulus is delivered during the vulnerable phase of the cardiac cycle. It correlates with the defibrillation threshold (DFT) and can be determined with a single episode of VF. The objective of this study was to test the hypothesis that ICDs programmed on the basis of the ULV convert spontaneous ICD-detected VF reliably. Methods and Results We studied 100 consecutive patients at ICD implantation and during follow-up of 20±7 months. At implantation, the ULV and DFT were determined, and the ICD system was tested at a shock strength equal to the ULV+3 J. During follow-up, the strength of the first shock was programmed to the ULV+5 J for arrhythmias detected in the VF zone (cycle length Conclusions ICD shocks can be programmed on the basis of the ULV, a measurement made in regular rhythm, without a direct measure of defibrillation efficacy.

This publication has 32 references indexed in Scilit: