Harrison 1987.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 30 Inclusion criteria: elective myocardial revascularization Exclusion criteria: pregnancy; AF or atrial flutter; atrioventricular conduction block > 1st degree; conditions that preclude beta‐adrenergic blocker treatment; MI within previous 3 months; severe hepatic or renal disease; SBP < 100 mmHg or cardiogenic shock; severe electrolyte imbalance; adrenergic augmenting drugs; long‐term beta‐adrenergic blocking drugs; calcium channel blocking agents Type of surgery: elective CABG Baseline characteristics Intervention group (esmolol) Age, mean (SD): 56.7 (± 2.06) years Gender, M/F: 13/2 NYHA III/IV: 15/0 Control group (placebo) Age, mean (SD): 56.0 (± 2.16) years Gender, M/F: 14/1 NYHA III/IV: 14/1 Country: USA Setting: single centre; hospital
Interventions	Intervention group (esmolol) Randomized, n = 15; losses = 0; analysed, n = 15 (use of ITT analysis not reported) Details: infusion of esmolol, diluted in a 1:25 solution with 5% dextrose, given IV before induction of anaesthesia, loading dose of 500 µg/kg/min for 4 min, followed by maintenance infusion of 300 µg/kg/min, continued until start of bypass Control group (placebo) Randomized, n = 15; losses = 0; analysed, n = 15 Details: infusion of 5% dextrose, given same as intervention group
Outcomes	Outcomes measured/reported by study authors: haemodynamic parameters, intraoperative myocardial ischaemia, intraoperative ventricular arrhythmias Outcomes relevant to the review: intraoperative ventricular arrhythmias
Notes	Funding/declarations of interest: supported by a grant from American Critical Care Study dates: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not specified
Allocation concealment (selection bias)	Unclear risk	Not specified
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Randomized, placebo‐controlled, double‐blind trial
Blinding of outcome assessors (detection bias) All outcomes	Low risk	Quote: "The ST trends and ECG strips were evaluated for myocardial ischaemia independently by a cardiologist who had no knowledge of the patient's treatment group"
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses
Selective reporting (reporting bias)	Unclear risk	Study authors did not report prospective clinical trial registration or publication of a protocol. It was not feasible to effectively assess risk of reporting bias
Other bias	Low risk	Not detected