Correlative studies between Frank vectorcardiograms and thallium-201 myocardial perfusion images in patients with old anterior myocardial infarction.

A correlative study was performed on 70 patients with old anterior myocardial infarction between each of the orthogonal components of instantaneous QRS vectors and the anterior-wall, lateral-wall and septal myocardial uptake ratios (A-MUR, L-MUR, and S-MUR, respectively). These MURs were calculated from the thallium-201 myocardial perfusion images at 5 projections and used as the index of the infarct size of the respective LV wall. The Z components of the 14-msec and 24-msec instantaneous QRS vectors significantly correlated with the S-MUR (r = -0.51) and the A-MUR (r = -0.66) respectively. The X component of the 32-msec instantaneous QRS vector also showed a significant correlation with the L-MUR (r = 0.59). The regression equations obtained in the present study seemed also applicable to patients with complete right bundle branch block. It is concluded that the quantitative analysis of the Frank vectorcardiograms could afford valuable information as to the size as well as the site of myocardial infarctions.