Sodium-hydrogen exchange inhibition: pre-versus post-ischemic treatment

Sodium-hydrogen exchange is involved in ischemia-reperfusion injury. Despit e the strong research support for the use of sodium-hydrogen exchange block ers to protect the myocardium during ischemia-reperfusion, there is still c ontroversy regarding the most effective time for drug delivery. Studies tha t initiate drug treatment immediately before or at reperfusion have given c onflicting results. The conflict in results may be due to differences in th e experimental design. Post-ischemic cardioprotection may be less than opti mal due to the vascular permeability barrier or a limited collateral circul ation. Increasing the drug dose or allowing more time for the drug to cross the vessel wall may overcome this limitation. Determining the correct dose and delivery protocol, therefore, will be critical for the generation of p ositive results in future clinical trials and will optimize the beneficial effects of sodium-hydrogen exchange inhibition in the treatment of reperfus ion injury.