Welcome LabCat. You will run again. The body is going to do what the body is going to do where the heart is concerned and so you might as well continue with your athletics as soon as you have recovered enough to get back to it.
Myself I am working at keeping a positive attitude about this stuff since my mother and my brother both have heart conditions. My chosen exercise routines involve yoga and self-training in martial arts. I have absolutely no intention of turning my back on either of those if my body is still capable of going the distance at all.