title: Patient-specific computational analysis of transvenous defibrillation: a comparison to clinical metrics in humans.
abstract: The goal of this study is to assess the predictive capacity of computational models of transvenous defibrillation by comparing the results of patient-specific simulations to clinical defibrillation thresholds (DFT). Nine patient-specific models of the thorax and in situ electrodes were created from segmented CT images taken after implantation of the cardioverter-defibrillator. The defibrillation field distribution was computed using the finite volume method. The DFTs were extracted from the calculated field distribution using the 95% critical mass criterion. The comparison between simulated and clinical DFT energy resulted in a rms difference of 12.4 J and a 0.05 correlation coefficient (cc). The model-predicted DFTs were well matched to the clinical values in four patients (rms = 1.5 J; cc = 0.84). For the remaining five patients the rms difference was 18.4 J with a cc = 0.85. These results suggest that computational models based soley on the critical mass criterion and a single value of the inexcitability threshold are not able to consistently predict DFTs for individual patients. However, inspection of the weak potential gradient field in all nine patients revealed a relationship between the degree of dispersion of the weak field and the clinical DFT, which may help identify high DFT patients.
authors.affiliation: Department of Biomedical Engineering, Boston University, 44 Cummington Street, Boston, MA 02215, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mocanu
authors.forename: Joachim
authors.initials: J
authors.lastname: Kettenbach
authors.forename: Michael O
authors.initials: MO
authors.lastname: Sweeney
authors.forename: Ron
authors.initials: R
authors.lastname: Kikinis
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Kenknight
authors.forename: Solomon R
authors.initials: SR
authors.lastname: Eisenberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D003198:Computer Simulation; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation / Q000379:methods*; D004574:Electromagnetic Fields; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011874:Radiometry / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013813:Therapy, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome