Preconditioning the human myocardium

Ischaemic preconditioning (short periods of ischaemia with intermittent reperfusion) has been shown paradoxically to protect the myocardium from a subsequent longer ischaemic insult. The protection associated with preconditioning is one of the most powerful mechanisms of protection known and has been shown in every animal species investigated. However, there is no direct evidence that ischaemic preconditioning occurs in the human heart. We studied whether it was possible to precondition the human heart in a setting of coronary artery bypass surgery. The measurement of adenosine triphosphate in biopsy specimens was used as our endpoint. We believe that our results are the first to show that it may be possible to precondition and protect the human myocardium with short controlled periods of intermittent ischaemia and reperfusion.