The objective of this study was to compare the haemodynamic and myocardial effects of pipecuronium and pancuronium in patients undergoing coronary artery bypass grafting (CABG) during benzodiazepine/sufentanil anaesthesia, Twenty-seven ASA III-IV patients received lorazepam (1-3 mg)po and midazolam (<.0.1 mg . kg(-1)) iv before induction of anaesthesia with sufentanil (3-8 mu g . kg(-1)). Vecuronium (0.1 mg . kg(-1)) was administered to facilitate tracheal intubation. According to random allocation, each patient received either pipecuronium (150 mu g . kg(-1)) or pancuronium (120 mu g . kg(-1)) after sternotomy but before heparinization. Mean arterial pressure, central venous pressure (CVP) pulmonary artery pressure (PAP) ST segment position and ECG (leads III, V-5, AVF) were monitored continuously throughout the procedure. Thermodilution determinations of CO in triplicate were made immediately before, and at two and five minutes after muscle relaxant administration.The objective of this study was to compare the haemodynamic and myocardial effects of pipecuronium and pancuronium in patients undergoing coronary artery bypass grafting (CABG) during benzodiazepine/sufentanil anaesthesia, Twenty-seven ASA III-IV patients received lorazepam (1-3 mg)po and midazolam (<.0.1 mg . kg(-1)) iv before induction of anaesthesia with sufentanil (3-8 mu g . kg(-1)). Vecuronium (0.1 mg . kg(-1)) was administered to facilitate tracheal intubation. According to random allocation, each patient received either pipecuronium (150 mu g . kg(-1)) or pancuronium (120 mu g . kg(-1)) after sternotomy but before heparinization. Mean arterial pressure, central venous pressure (CVP) pulmonary artery pressure (PAP) ST segment position and ECG (leads III, V-5, AVF) were monitored continuously throughout the procedure. Thermodilution determinations of CO in triplicate were made immediately before, and at two and five minutes after muscle relaxant administration.