Model study of vector-loop morphology during electrical mapping of microscopic conduction in cardiac tissue

In this preliminary study we examined the effects of fiber curvature on the vector loops calculated in the extracellular field. An interconnected cable model of a two dimensional sheet of atrial tissue was used to model propagation. Activation was simulated for sheets of tissue, with both curved and straight fibers. The resultant extracellular field and vector loops were then calculated for both cases. Consistent with previous work, we found that the vector loop can be used to predict the local direction of propagation to within 5% for the case of straight fibers. In the case of curved fibers the accuracy is reduced somewhat (maximum error of 14%).