Mrs. Leland, a 62 year old female, presented to the ER with…

Mrs. Leland, a 62 year old female, presented to the ER with complaints of sense of uneasiness and severe fatigue for a few days now. After ruling out a few possible differential diagnosis, the attending physician narrowed it down to possible myocardial ischemia. As a student nurse practitioner, you know the pathophysiology behind this is: