<s>[INST] my father died of a cardiac arrest. However, he had an abdominal aortic dissection that was detected on the last day. his intestines, gall bladder and part of the liver were removed. BP and pulse were high during the operation. later stabilised. then at 1.20 am, he had a cardiac arrest and passed away. He had no history of blood pressure, or heart disease.He first reported stomach, back n chest pain on 7th december, 2010. Also fainted and vomitted. However, doctors suspected food poisoning, colitus and later gall bladder inflammation. the actual problem was discover on 23rd Decemeber, he died later the same night.(24th december) I need to know how and why this happened [/INST] Hello, Cardiac arrest is usually the mode of death in majority of the cases. Whenever any disease becomes severe, it ultimately lead to cardiac arrest and death. In his case, it is aortic aneurysm. I don't know entire scenario here, but just considering the information you have provided, it may be possible that aneurysm might have ruptured leading to blood loss, low BP and leading to cardiac arrest. Did he has any infection or sepsis which can also cause low BP and cardiac arrest which ultimately leads to death. Hope this helps you and get back if you have any doubts. Take Care Regards Dr. Sagar Makode, Cardiologist </s>