T.L.: Digital computer model of a total body electrocardiographic surface map: Adult male-torso simulation with lungs. Circulation

A 20-dipole digital computer model of the electromotive surface generated by the heart with a simulated human male torso, including lungs, is presented. The simulated torso-surface ECG equipotential maps were compared to those seen in normal human subjects by Taccardi and were found to resemble them to within the resolution of these maps throughout most of ventricular depolarization (QRS). On comparison of the simulated maps to those produced when the heart was considered to be a single equivalent dipole, it was found that normal surface maps contain considerable in-formation not accounted for by an equivalent dipole source during the mid and terminal portions of the QRS. This information occurs in areas not sampled by a standard pre-cordial electrocardiogram. The addition of the lungs did not appear to change the surface ECG map in any important respect. Additional Indexing Words: Computer heart model ECG equipotential surface maps Heart simulation Equivalent dipolb ECG computer simulation A MATHEMATICAL MODEL of the vec-torcardiogram (VCG) with the heart considered to be a set of 20 distributed dipoles eccentrically placed in a sphere of uniform conductivity was recently reported.' Agreement was observed in this model be-tween the simulated data and the clinical, VCG, and electrocardiographic (ECG) data of normal subjects and of patients with vary-ing degrees of right and left ventricular by-pertrophy, and large and moderate-sized myocardial infarcts. Simulated total body ECG equipotential maps of a normal heart in a normal homogenous male torso, recently published,2 were similar to those recorded by Taccardi3 in normal subjects. In the present simulation, the set of 20 distributed dipoles which simulates the cardi