I can't speak from experience on the inappropriate shocks, the couple of jolts that I had were enough for me (thanks, but no thanks on more
My problem was different than your mother's (mine was due to plaque buildup/rupture which led to the heart tissue damage/MI at age 35).
Anyway, what I can tell you about is the anxiety. Yes, it's normal for survivors to have this. I did read that 95% of all survivors do suffer some form of anxiety or another.
For the first 6 months, I was anxious to the point of making two additional trips to the ER because I thought I felt angina again. It turns out I was wrong. After the 2nd of those, my GP suggested that I try PaxilCR. I gave it a go for 3 days and I was crawling up the walls on that the third night, feeling more anxiety than ever. That was the end of the Paxil. A few days later, I went into the GP and thanked him for the Paxil because now I understand what anxiety is really like.
Since then, my attitude is that we all go one day and there is just no point in getting worked up about it--my time will come. In the mean time, I am going to do the best I can, run every day, eat well and do those things I can to prolong life. For whatever reason, that short episode of Paxil got me over the hump. I can't say that I have experienced any related anxiety (or even unrelated) for the past 3 years, since that point.