ST segment elevation on the EKG represents acute injury and is the hallmark of a myocardial infarction. The surface EKG is not precise in localizing which coronary artery is occluded with thrombus, but it is very helpful. Before you have gotten your EKG back, you would think of a differential diagnosis- or list all possible things that could cause chest pain. There are many other possibilities, as well, and each possible diagnosis would have specific points in its favor with the history and physical examination. The pain of an acute MI can be highly variable.
Some patients only feel short of breath, nausea or fatigue.
The physical examination in this patient reveals hypertension and tachycardia, both of which increase the myocardial oxygen demand. At this point, we do not know if the hypertension and tachycardia are causing the problem, or are a result of the ischemic pain. The first response of the left ventricle to ischemia is that it becomes more stiff, or noncompliant. This increases the end diastolic pressure of the left ventricle which can cause shortness of breath and crackles on the lung exam. There are a number of medically acceptable options to treat this patient.