Introduction: Recently, noninavasive electrocardiographic imaging (ECGI) has been gaining increasing attention due its potentially tremendous clinical value in treatment of patients with dysfunctioning cardiac electrical propagation system. However, the wide adoption of this promising methodology is apparently dependent on clinical validation results against the invasive information.
Methods: In this work, we evaluated the ECGI accuracy by noninvasive localization of biventricular pacemakers in ten patients with a programmable cardiac resynchronization therapy (CRT) device. Torso and body geometries as well as precise pacemaker positions were obtained from computed tomography scanning. For numerical reconstructions, three established spatiotemporal regularization approaches were tested in combination with different techniques for earliest excitation site identification.
Results: The reconstruction quality depended on the pacemaker anatomical position in heart with a superior accuracy for the left-ventricular free wall in comparison to the right-ventricular basal and septal areas. Distinct regularization methods performed similarly and resulted in minor accuracy differences. Application of a spatiotemporal approach for activation times calculation further improved the median localization error to 15 mm.
Conclusion: Although ECG imaging showed a clinically acceptable median accuracy, intra-patient variability and deterioration in the accuracy of septal reconstructions should be addressed in the future studies.