Recently, I was asked to consult on a patient with ulcerative colitis. The patient was a male, 42 years old. He was admitted to the hospital with mucopurulent stools for 6 months. He had mucopurulent stools 6 months ago, with 5-15 stools/day, with paroxysmal pain in the left lower abdomen and no fever. He came to the hospital with no improvement in symptoms after 3 months of self-medication with flavopiridol, pyrimethamine and dysentery. No previous history of hypertension, heart disease, diabetes mellitus, hyperlipidemia, etc. The colonoscopy revealed diffuse congestion, edema and erosion of the whole colonic mucosa with superficial ulcer formation, covered with thin white moss and purulent secretions, and the pathological examination showed colonic mucosal ulcer and crypt abscess formation. Blood sedimentation was 42 mm/h, platelets were 450×109/L, and the electrocardiogram was normal. Diagnosis: chronic non-specific ulcerative colitis (active stage, total colitis, moderate). After admission, the patient was given oral salazosulfapyridine 1 g, 4 times/day; prednisone 10 mg, 1 time/day; because of the severe symptoms of blood in the stool, hemostatic minerals and hemostatic cyclic acid were given. After 2 weeks of treatment, the symptoms of mucopurulent stool were relieved significantly. 1 week ago, the patient suddenly felt pressure-like pain in the precordial region, radiating to the jaw and left shoulder and back, and died of acute anterior wall extensive myocardial infarction on emergency electrocardiogram. The patient had no previous history of hypertension, heart disease, diabetes mellitus or hyperlipidemia, and the electrocardiogram was normal at the time of admission, so how could myocardial infarction occur during the treatment?