Electrophysiological imaging of volumetric infarct border using a spatio-temporal LP-norm constraint

Abstract

Imaging the bioelectrical source distribution along the infarct border is of important therapeutic potential as infarct border is the common site for reentry circuits leading to life-threatening arrhythmias. Although it can be tackled by computational reconstruction of volumetric cardiac source using body-surface voltage data, the problem is notoriously ill-posed without a unique solution. Progress towards 3D cardiac source reconstruction is further hindered by the complex spatio-temporal property of cardiac current sources, which decides that common L1 and L2-norm constraints are not proper because the underlying assumption is either too focal or too smooth to reflect the property of the source distribution. In this work, we propose a general regularization with Lp-norm (1 <; p <; 2) constraint to bridge the gap between L1 and L2 solutions in cardiac source reconstruction along the infarct border. We further incorporate temporal information into Lp-norm constraint to promote consistency over time as well as robustness to noise. In a set of computer-simulated and real-data experiments, we demonstrate the superiority of the proposed method in reflecting the complex spatial structure of source distribution along 3D infarct border during the ST-segment of an ECG cycle, over L1 or L2 counterparts.