Body surface potential mapping and computer simulation of human ventricular fibrillation

Our aim was to study the electrical characteristics of human ventricular fibrillation (VF) by means of body surface potential mapping and heart-model simulations. We acquired 120-lead ECG data on the chest surface of patients undergoing controlled testing of implantable defibrillators. VF was induced by burst pacing, and ECGs were recorded for 5 to 7 seconds before the device delivered a rescue shock. We then used orthogonal decomposition to characterize spatial and temporal features of ECGs, and inverse solution to derive epicardial potential maps. To gain insight into mechanisms of VF, we used an anisotropic bidomain model of the human ventricular myocardium, featuring 5 ionic currents. The model showed meandering VF scroll waves exhibiting break-up and coalescence according to choice of ionic-current parameters. This combination of experiments and simulations offers a unique perspective on the origin of spatial patterns of ECG during VF.