Without finishing his sentence, he drove the implement into the side-wall of the tunnel, a little in front of the pillar of masonry that supported the hinges of the door.
Leads I and aVL, along with two of the chest leads, V5 and V6, are all considered " lateral" leads and they're near the lateral wall of the heart which receives blood from the left circumflex artery.
Ischemia in the areas supplied by the partially occluded vessel illustrated here in the lateral wall of the left ventricle is primarily targeted on the sub endocardial aspect of the affected region.