To the Editor:—
In an excellent review of myocardial protection during anesthesia, Warltier et al. 1mention the possibility of improving oxygen availability to the myocardium by a right shift of the oxyhemoglobin dissociation curve. 2–4The beneficial effects of β-blocking drugs also are reviewed. However, the correlation of the well-known fact that β-blockers shift the curve to the right is omitted. This rightward shift may promote oxygen delivery to the myocardium during ischemia. The clear reduction in perioperative infarction rates after β-blockade rests on this fundamental effect.