Usage of statistical estimation method for the simultaneous mapping of inner and outer surfaces of the heart

To characterize the cardiac rhythm disturbances catheter-based cardiac mapping approaches have become a common practice due to their minimal invasiveness. A multielectrode basket-shaped contact catheter and the multielectrode intravenous catheter are two types of the used catheters. Catheter based approaches provide mapping of the one surface at a time. Therefore, there is a need for a method that can achieve mapping of the inner (endocard) and outer (epicard) surfaces of the heart in one heart beat. In this study, for simultaneous mapping of epi/endocardial surfaces multielectrode basket-shaped catheters and intravenous catheters we used statistical estimation method. In order to test this approach we used three dimensional simulations of the electrical activity of the heart. For this purpose, we created a simulation database using Aliev-Panfilov model. Our simulation database included 3880 maps formed by starting the simulations from endocardial, myocardial and epicardial sites. Half of these maps were used as training data and the rest were used as test data. We selected 64 points on left and 64 on right endocardial surfaces as multielectrode basket catheter measurement sites and 91 sites on epicardial surface as the intravenous catheter measurement sites. To test the performance of this approach we used criteria such as correlation coefficient (CC), root mean squared error (RMSE), relative error (RE) and localization error (LE). As a result, between the estimated and original maps CC is ∼0,98, RMSE is ∼2,7 ms, RE is ∼0,05 and LE is 5–6 mm.