A 74 y.o. patient complains of abdomen pain and sweling, nausea. She suffers from ischemic heart disease, postinfarction and atherosclerotic cardiosclerosis. Objectively: the patient is in grave condition, abdomen is swollen, abdominal wall doesn't take active part in respiration. Laparoscopy revealed a small amount of muddy effusion in abdominal cavity, one of the loops of small intestine is dark-cyan. What is the most probable diagnosis?