Sudden disappearance and reappearance of the pathologic Q waves after successive myocardial necrosis: electrocardiographic and pathologic correlations.

A case with sudden disappearance of the pathologic Q waves of an old posterior myocardial infarction after a superimposed acute anterior infarction is reported. This phenomena probably is due to the loss of the opposing electromotive forces in the anterior myocardial wall after acute anterior myocardial necrosis. When a third acute lateral myocardial infarction occurred, new Q waves in the corresponding leads could be observed. Pathologic examinations documented three temporally and spaciously separate infarctions. Such correlations allow a better understanding of the electrocardiographic changes in patients with successive myocardial infarctions.