<s>[INST] My husband was a dialysis patient. He complained of back pain and laid down with a heat pad on his back. A couple hours later, He died in his sleep and there was vomit. Could that have been a heat attack. He had a history. A mild heart attack , had two stints and AFib. But the AFib was treated by ablation a couple year prior. [/INST] Dear madam, welcome to Chat Doctor. I am sad to hear about your husbands demise. Please accept my condolences. The most common reason for death in dialysis patients is cardiovascular (Heart attack, Strokes, heart rhythm problems, etc.). One of the conditions which I think is most likely in your husbands' case is Dissecting Aortic Aneurysm which can cause back pain and many a time can be life-threatening. A myocardial infarction (heart attack) is always very high on the list of probabilities off course. Unlikely he died of a heart attack. Hope this helps. Kind regards. RB </s>