Greetings. Thank you for your question and welcome to HCM. I understand your concern. Well, we have to take this step by step. First, I am assuming this was a massive heart attack, that left the heart function with 20%, where normal range is 55-70%. This means that, besides this heart pumps only 20% of its content forward, and thus does not satisfy end-organ needs for pure blood with oxygen and nutrients, it also keeps 80% of its content without pumping forward and this consists a great resistance for the blood coming from the lungs to empty into the heart, therefore the pressure will be high backwards. Both these mechanisms may produce serious, potentially life-threatening scenarios. The weaker the heart (the lower the function), the greater the probability of these scenarios happening. So, everything that impedes forward pumping or raises backward pressures should be eliminated from the diet. I am referring mostly to the excessive water and, particularly, to salt. 1 gram of salt retains 10 grams of water. So, my recommendation would be no salt in diet. I also recommend that she should carefully respect and adhere to treatment regimen, because this insufficient heart is highly dependable from medication, in order to maintain a balance in organism. Another matter is that the enlarged heart muscle, makes the cells stretch and separate from each other and scar tissue is placed in between them. This phenomenon triggers malignant, serious, life-threatening ventricular arrhythmia, so you should discuss with your cardiologist about the possibility of implanting an implantable cardioverter-defibrillator (ICD), which is a pacemaker-like battery, placed under the skin, and automatically electrically shocks the patient if a ventricular arrhythmia occurs. I hope I was helpful with my answer. Feel free to ask again. Best regards, Dr. Meriton