Extent of the inferior myocardial infarction assessed by the frontal plane of the vectorcardiogram.

ABSTRACT

A correlation was made between the vectorcardiographic changes and the peak value of the L.D.H. in the serum of 21 patients with acute inferior (diafragmatic) M.I. The following vectorcardiographic variables showed changes proportional to the increase in serum L.D.H. The correlation was found to be statistically significant. The direction of the 0.025 sec vector (r = 0.63, P less than 0.005). The duration of the initial superior forces of the QRS loop (r = 0.87, P less than 0.001). The maximal leftward deviation of the initial superior QRS loop forces (r = 0.65, P less than 0.005). The maximal superior deviation of the initial QRS loop forces (r = 0.68, P less than 0.05). The ratio of the maximal superior deviation over the maximal inferior deviation of the QRS loop "QY/RY" (r = 0.76, P less than 0.001). The area under the initial superior forces of the QRS loop and over 0 degrees +/- 180 degrees axis in squared milimeters (r = 0.88, P less than 0.001). It is suggested that V.C.G. is a usefull means in assessing the extent of inferior M.I.