15. How would a partially blocked coronary artery near the ventricles affect the QRS complex of an EKG? Why?

If the area of the ventricle which is supplied by the blocked coronary artery contains any part of the electrical conducting system, then this will cause the electrical signal to have to disperse through the rest of the muscle of the ventricle instead of going through the damaged conducting system. The conducting system conducts electrical signals faster than the muscle of the ventricle, so the QRS complex will last longer, meaning that it will appear wider on the EKG tracing, and will also affect the QRS axis as well, since the electrical signal will be conducted through the heart in a different direction than if the conduction system was intact.