Geez, man, sorry to hear what you went through. Glad you came through it and are getting back on track.
Did the doc say why you need to train light? As in, are you not allowed to strain with weights (to avoid the valsalva maneuver's temporary spike in blood pressure) or do you need to keep your heart rate below a certain threshold?
I'm wondering because it's totally possible to use a light weight (15RM) and go through an intense workout with complexes, like Badger suggested. Or you could train with a 15RM but work in sets of 10-12, keep rest periods supershort, and use techniques like drop sets or rest-pause.
But if you're supposed to keep overall training intensity low until you get the all-clear, then "boring" bodybuilding with 3x15 per exercise, 2-3 exercises bodypart, might be where you're at for now.
Again, the program would depend on exactly what you can and can't do for now. These are a few 2/wk routines that you might get some ideas from:
You might also want to check some of Paul Carter's stuff, particularly the 350 Method discussed here, for ways to build muscle without focusing on going super-heavy: