My father suffered a major cardiac arrest last year and his ejection fraction has decreased to 37 percent from the left ventricle, it was a case of myocardial infarction, he is undergoing medical plan management and he is stable now, he has been suffering from diabetes since 15 years, but now both diabetes and cholesterol levels are under control, what could be the future complications as he is working under a private firm and he has to take 6 classes a day, so could he handle so much stress from the heart point of view, please reply to the query about future complications, he is conscious about his diets, physical fitness as advised by the cardiologist, I mean what should he not do regarding heart health point of view so that his heart works efficiently.