Delayed protection of the heart against ischaemia.

Ischaemic preconditioning is the protective adaptive mechanism produced by short periods of ischaemic stress that results in a marked resistance of the myocardium to prolonged periods of the same stress; however, this protection is transient. There is now evidence that protection resulting from preconditioning returns several hours later, and here James Parratt and Laszlo Szekeres highlight the possible importance of this concept, which may lead to novel approaches to the long-term protection of the heart against ischaemic injury.