Cardiovascularmiddle twist
A 64-year-old woman with cirrhosis presents with fresh haematemesis and melaena. After intravenous access, cautious crystalloid and cross-matched blood have been arranged, she remains at 112/70 mmHg with a pulse of 58 beats/minute. She has severe stable coronary artery disease with exertional angina and is awaiting revascularisation. Variceal bleeding is considered likely, and endoscopy is being arranged. Which one of the following is the most appropriate vasoactive treatment while she awaits endoscopy?