title: Computational methods to reduce uncertainty in the estimation of cardiac conduction properties from electroanatomical recordings.
abstract: Cardiac imaging is routinely used to evaluate cardiac tissue properties prior to therapy. By integrating the structural information with electrophysiological data from e.g. electroanatomical mapping systems, knowledge of the properties of the cardiac tissue can be further refined. However, as in other clinical modalities, electrophysiological data are often sparse and noisy, and this results in high levels of uncertainty in the estimated quantities. In this study, we develop a methodology based on Bayesian inference, coupled with a computationally efficient model of electrical propagation to achieve two main aims: (1) to quantify values and associated uncertainty for different tissue conduction properties inferred from electroanatomical data, and (2) to design strategies to optimize the location and number of measurements required to maximize information and reduce uncertainty. The methodology is validated in an in silico study performed using simulated data obtained from a human image-based ventricular model, including realistic fibre orientation and a transmural scar. We demonstrate that the method provides a simultaneous description of clinically-relevant electrophysiological conduction properties and their associated uncertainty for various levels of noise. By using the developed methodology to investigate how the uncertainty decreases in response to added measurements, we then derive an a priori index for placing electrophysiological measurements in order to optimize the information content of the collected data. Results show that the derived index has a clear benefit in minimizing the uncertainty of inferred conduction properties compared to a random distribution of measurements, reducing the number of required measurements by over 50% in several of the investigated settings. This suggests that the methodology presented in this work provides an important step towards improving the quality of the spatiotemporal information obtained using electroanatomical mapping.
authors.affiliation: Department of Computer Science, University of Oxford, UK; Fraunhofer-Chalmers Centre, Gothenburg, Sweden. Electronic address: mikw@cs.ox.ac.uk.
authors.forename: Mikael
authors.initials: M
authors.lastname: Wallman
authors.forename: Nicolas P
authors.initials: NP
authors.lastname: Smith
authors.forename: Blanca
authors.initials: B
authors.lastname: Rodriguez
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000465:Algorithms; D018780:Body Surface Potential Mapping / Q000379:methods*; D006329:Heart Conduction System / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Bayesian inference; Cardiac modelling; Electroanatomical mapping; Model personalization; Parameter estimation