Myocardial electrogenesis and the electrocardiogram

Determinants of the electrocardiographic voltage are reviewed with formulation of certain parameters. The dipole moment of a single fiber and consequently, a possible maximal moment of the double layer of the activation wave front are estimated as 0.21 mA.cm per unit area (cm2). The longitudinal activation of parallel fibers produces much stronger double layer than the transverse activation across fibers. Without any loss of the electrical force of fibers, a normal ventricle of 200 g in weight would create a possible maximal QRS area of 350 microV.sec in a surface lead. The normal endo- to epicardial ventricular activation is predominantly transverse with respect to fiber orientation and rather inefficient in electrogenesis. It is implied that abnormalities in ventricular conduction may possibly improve the effectiveness of myocardial generator.