Table 1 Inclusion and exclusion criteria

All admitted patients with the primary discharge diagnosis of ulcerative colitis

Complicated with any one of the conditions: sepsis, septic shock, active gastrointestinal bleeding, heart failure with NYHA Class II-IV, myocardial infarction or stroke within 3 months, liver cirrhosis with decompensation, chronic kidney disease stage IV or V

Female patients who are pregnant

The diagnosis of ulcerative colitis is established by symptoms, colonoscopy and histology

ECG with any one of the conditions: non-sinus rhythm, ventricular pre-excitation syndrome, any atrial or ventricular premature beat on ECG recording, bradycardia with resting heart rate less than 50 bpm, tachycardia with resting heart rate more than 120 bpm

Have at least one colonoscopy with biopsy during admission

Taking any one type of the medications a week before or during admission: beta-blocker, muscarinic cholinergic-blocker/agonist

Have at least one standard 12-leads ECG during the first 24 h of admission

Active infection of any of the pathogens: mycobacterium tuberculosis, CMV, EBV, HAV, HBV, HCV, HDV, HEV