Automated Vulnerability Testing Identifies Patients With Inadequate Defibrillation Safety Margin Article

Industry Collaboration

cited authors

  • Birgersdotter-Green, Ulrika, Ruetz, Linda L., Anand, Kishlay, Monir, George, Abeyratne, Athula I., Bailey, J. Russell, Shorofsky, Stephen R., Hsia, Henry H., Friedman, Paul A.

funding text

  • Dr Birgersdotter-Green, Dr Shorofsky, Dr Friedman, and Dr Hsia have received research grants/support from Medtronic. Dr Birgersdotter-Green and Dr Hsia have received honoraria from Medtronic. Dr Shorofsky has received fellowship support from Medtronic. Dr Monir and Dr Hsia are consultants to Medtronic. Ruetz and Abeyratne are Medtronic employees. Dr Birgersdotter-Green and Dr Shorofsky have received research grants from Boston Scientific. Dr Birgersdotter-Green and Dr Shorofsky have received honoraria from Boston Scientific. Dr Birgersdotter-Green and Dr Shorofsky have received research grants from St. Jude. Dr Birgersdotter-Green and Dr Hsia have received honoraria from St. Jude. Dr Friedman has received research support from Biotronik and has served as consultant or received speakers fees from St. Jude and Biotronik. Dr Bailey reports no conflicts.

abstract

  • Background-Implantable cardioverter-defibrillator system efficacy is tested at implant by induction of ventricular fibrillation (VF). Defibrillation safety margin can be assessed without VF induction using upper limit of vulnerability methods, but these methods have required manual determination of T-wave timing. Methods and Results-To test the feasibility of an inductionless system of implant testing, a multicenter prospective study of an automated vulnerability safety margin system was conducted, which measured T-wave timing using an intracardiac electrogram during a ventricular pacing train. The system delivered up to 4 T-wave shocks of 18 J. Lack of VF induction by all 4 shocks was considered evidence of defibrillation adequacy. Patients subsequently underwent conventional defibrillation testing to meet a standard implant criterion. The 95% lower CI for defibrillation success at 25 J for noninduced patients was found using Bayesian statistics. Sixty patients were enrolled at 6 centers. Vulnerability testing and defibrillation success results were obtained from 54 patients. Vulnerability testing induced VF in 10 (19%) patients, of whom 2 required system revision. All patients not induced by vulnerability testing were successfully defibrillated twice at <= 25 J. The Bayesian credible interval was 97% to 100% for the population success rate of defibrillation at 25 J for automated vulnerability safety margin noninduced patients. Conclusions-An automated system identified all patients who failed conventional safety margin testing, while inducing only 19% of patients. Although limited by sample size, this study suggests the feasibility of automated implant testing that substantially reduces the need for VF induction in patients receiving implantable cardioverter-defibrillators. (Circ Arrhythm Electrophysiol. 2012;5:1073-1080.)

authors

Publication Date

  • December 1, 2012

webpage

published in

category

start page

  • 1073

end page

  • 1080

volume

  • 5

issue

  • 6

WoS Citations

  • 7

WoS References

  • 26