http://www.mayoclinic.com/health/cardiac-ischemia/HQ01646http://yourtotalhealth.ivillage.com/cardiac-ischemia.htmlHere are two links that help to explain things. The first is quite simple while the second is much more detailed.
My understanding is that ischemia means that a particular area of the heart (inferoapical in your case) is not being adequately supplied with oxygen. There can be several reasons for this but essentially it means that the arteries are affected and in turn so is the heart. Atherosclerosis or hardening of the arteries is one possibility but the bottom line is that ischemia puts you at a higher risk for a heart attack and so it needs to be treated. Your doctor will decide how best to do this, depending on the underlying cause.
There are also things that you can do. Eating less fatty foods, getting more exercise, not smoking are three key issues for every person but especially for us with ESRD because kidney health and heart health are very interconnected.
I hope you're doing well with the efforts to quit smoking Paul, and please let us know how your doctors decide to treat this so you can be active on the list. All good wishes.