ed34's post is accurate in my opinion. ECG's are not always accurate, but they do indeed show heart issues. I'd have a stress test to check out the ECG's accuracy, or at least ask for a second ECG.
I've had cataract surgery, and indeed, it is an emotional event. I'd cover Mom's bases if possible with a stress test.
Yes in some cases ischemia can be detected using an EKG. If the procedure is local anaesthetic then I assume this would have little effect on the heart, but there is the obvious anxiety during the operation.
Yes, it is done under local anaesthetic and the surgery only takes but 15 minutes - 30 minutes if you count the preparations before hand. They have this reqirement to protect themselves againt lawsuits if something should go wrong - me thinks. I had an EKG done at the time, but nobody said anything about blockage and how much. How can they detect it this way anyway?
Isn't cataract surgery done under local anaesthetic?
I believe it will be up to her doctor, but in my opinion the heart is more important than the cataract surgery at this time. If it was my family member, I would highly suggest that you follow up with the heart investigation first.