Chinese researchers tested the myocardial protecting effects of a Ginkgo biloba extract (Ginaton) on ischaemic-reperfusion injured myocardium during cardiopulmonary bypass. A total of 20 patients undergoing mitral valve replacement were randomly divided into two groups: Control group comprised 10 patients that received intermittent intra-aortic infusion with cold St Thomas solution during hypothermic cardiopulmonary bypass; Ginaton group comprised 10 patients that received intermittent intra-aortic infusion with cold St Thomas solution containing Ginaton (0.5 mg/kg). Changes of ultrastructural levels of ATP, malondialdehyde and haemodynamic data were measured. Haemodynamic parameters in the Ginaton group were maintained better than those in the control group. Malondialdehyde in the control group was significantly elevated during ischaemic reperfusion, while in the Ginaton group there were no obvious changes. After declamping of the aorta, ATP levels and energy change were significantly higher in the Ginaton group than in the control group. The percentage of normal mitochondria and glycogen content was significantly higher in the Ginaton group than in the control group at declamping aorta.