(A and B) Experimental groups and setups. (A) Setup for non-infarcted hearts. (B) Setup for infarcted hearts. BCP: blood cardioplegia; CP: cardioplegia; CF: coronary flow; EBCP: esmolol blood cardioplegia; ECCP: esmolol crystalloid cardioplegia; lactate: myocardial lactate production; haemodynamic: haemodynamic measurements; LAD: left anterior descending artery; N: hearts per group; O₂: myocardial oxygen consumption; TTC staining: triphenyl tetrazolium chloride staining.