Explanation for the electrocardiogram in subendocardial ischemia of the anterior wall of the left ventricle.

Recently, an important electrocardiogram picture indicating anterior wall ischemia was discussed, characterized by (1) loss of R wave and (2) not infrequently a notch in the negative limb of the QRS complexes in the precordial leads, combined with (3) ST depression and (4) a tall peaked T wave. An explanation of this electrocardiogram picture is offered based on the likely subendocardial localization of the ischemia and the resulting behavior of the subendocardial action potentials compared with the subepicardial action potentials.