Vectocardiographic Lead Systems for the Characterization of Atrial Fibrillation

Objective The aim of the study was to design a vectorcardiographic lead system dedicated to the analysis of atrial fibrillation (AF). Methods Body surface potentials during AF were simulated by using a biophysical model of the human atria and thorax. The XYZ components of the equivalent dipole were derived from the Gabor-Nelson equations. These served as the gold standard while searching for an optimal orthogonal lead system for the estimation of the heart vector while using a limited number of electrode positions. Six electrode configurations and their dedicated transfer matrices were tested by using 10 different episodes of simulated AF and 25 different thorax geometries. Results Root-mean-square–based relative estimation error of the vectorcardiogram using the Frank electrodes was 0.39. An adaptation of 4 of the 9 electrode locations of the standard electrocardiogram, with 1 electrode moved to the back, reduced the error to 0.24. Conclusion The Frank lead system is suboptimal for estimating the equivalent dipole components (VCG) during AF. Alternative electrode configurations should include at least 1 electrode on the back.