The loss of electrically active myocardium in cardiogenic shock.

A method of precordial mapping of RS ratio changes and the appearance of Q waves that occur in acute myocardial infarction has been developed. The serial changes of R and Q waves in 40 patients suffering uncomplicated anterior infarction shows that the loss of electrically active myocardium occurs within 6 h from the onset of chest pain. The total precordial ECG changes of R and Q waves in 5 patients suffering anterior infarction and cardiogenic shock showed that the loss of electrically active myocardium continues after 6 h from the onset of chest pain, and is significantly different from the uncomplicated group. This was supported by the serial plasma MBCK activity determinations which suggest more than one episode of necrosis.