EXPERIMENTAL MODEL FOR EVALUATION OF CARDIAC DEFIBRILLATION.

A computer model of the thorax has been developed which has made it possible to systematically investigate the effects of electrode position on current density in the region of the heart. The computer model of the human torso incorporates an exact anatomical shape of the heart, lungs and torso, and conductivity inhomogeneities in the torso. The electrocardiographic body-surface potential distribution and magnetic field around the body in the normal state and in patients with pathological heart conditions. The use of this model has been extended to include this study of cardiac defibrillation. The results indicate that the electrode positions most commonly utilized for defibrillation are not necessarily the best choice. Other electrode positions could be used which provide more uniform current density through the heart with less likelihood of damage without requiring an excessive increase in shock. These studies open the question of reconsidering the choice of electrode positions for defibrillation.