Mapping myocardial activation distributions using neural networks: 2-D simulation results.
The goal of this study was to explore the capabilities of neural networks to map with accuracy the sequence and location of myocardial activation using QRS complexes simulating normal and altered activation. A two-dimensional (2-D) fractal-based computer model of myocardial activation was used to develop training data for initial network learning. Two types of activation scenarios were used to evaluate network learning: 1) 450 training sets based on three activation foci per set using randomly chosen times and activation sites, and 2) 199 training sets based on a sequential, hierarchical blocking of the fractal-based model conduction network. Network learning was evaluated with training and test cases using trained weights. Network-calculated activation maps compared with the target activation maps had a mean error of < 5% in assigning the site and timing of activation. Pointwise mean correlation coefficients were > 0.98 for all conduction network cases and > 0.84 for the more demanding point foci cases. We conclude, based on these simulation results, that neural networks may be used to calculate activation maps using electrocardiogram lead data for a variety of activation patterns.
Nelson
T R
TR
Department of Radiology, University of California, San Diego, La Jolla 92093.
Boone
J M
JM
D000818:Animals; D003198:Computer Simulation; D004562:Electrocardiography; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D016571:Neural Networks, Computer