 The investigators decided to make a study with a cohort of patients as homogenous as possible with a cross clamp time around 70 min. Adult patients with a severe aortic stenoses without any other significant heart disease was included in our prospective randomised study. This group of patients was chosen for two reasons. First, these patients have left ventricular hypertrophy making the myocardium vulnerable to ischemia, secondly the investigators wanted to avoid the possible confounding effect of ischemia found in patients with variable degrees of coronary artery disease. Therefore, patients with additional significant coronary artery disease 50 stenoses were excluded from the study. 