Ischemic Preconditioning at a Distance

Abstract
Background Limitation of myocardial infarct size by an earlier brief complete occlusion of a coronary artery is defined as ischemic preconditioning. However, myocardial protection also can be achieved by partial reduction of coronary flow, rapid cardiac pacing, or brief ischemia-reperfusion of a remote region of the heart. Our study assesses the effect on myocardial infarct size of preconditioning at a distance induced by partial reduction of blood flow to a hind limb with or without increase of demand by electrical stimulation of a skeletal muscle. Methods and Results Anesthetized rabbits were randomized to 30 minutes of waiting period (controls), 55% to 65% reduction of femoral artery blood flow (stenosis), electrical stimulation of the gastrocnemius muscle at a rate of one per second (stimulation), or stenosis+stimulation. Thereafter, rabbits underwent 30 minutes of coronary artery occlusion and 4 hours of reperfusion. Each group included 8 rabbits. Risk zones were comparable among groups. However, the...