Found this from musclemag
Ever since news broke last week of Nasser El Sonbaty’s passing, the Internet has been aflame with rumors of all sorts as to the cause of death. In many ways the continued discussion among bodybuilding fans is a testament to the impact Nasser had on the sport. For this reason we greatly appreciate Guillermo Tom taking the time to clarify the circumstances once and for all.
“Nasser had been ill for sometime. In November he was admitted to the hospital here in San Diego for breathing problems. It was then that he was diagnosed with heart failure and kidney damage. He was on dialysis from that day on. The doctors told him he was not a candidate for a heart transplant because his heart was too weak. He went back to Egypt to visit his family, which consisted of his mother, father and one sister. He died in his sleep while in Egypt. Whether or not it was caused by any of the illnesses I mentioned, we do not yet know. That’s the true story.”
Nasser was a big man. Big men and women tend to have more health problems. Our hearts don't get bigger when we add weight, be it muscle weight or fat. The more one weighs the harder one's heart has to work. Often there is a tie-in with heart failure and kidney failure.
My wife has congestive heart failure and kidney failure. She has managed to forestall dialysis through diet and medication. However her kidney function is around 20% give or take. 15% is certain dialysis. She uses oxygen 24/7 to help with the congestive heart failure. And no, she is not a smoker nor is she morbidly obese, although she has never been a skinny mini either.
My sister has been having a lot of trouble breathing lately. The doctor discovered she had a blockage in the heart. A couple of weeks ago she had an angioplasty. Her breathing is somewhat better, but not normal. She is 54 years old.
It is good that Nasser was able to see his family and to die in his sleep. Many people die before they have a chance to say goodbye to those they care about.