A method and device for treating myocardial ischemia are described in which the stress experienced by a myocardial region identified as vulnerable to becoming ischemic is varied with pre-excitation pacing. In an unloading mode, pacing is applied in proximity to the vulnerable region to reduce stress and the metabolic demand of the region. In a loading mode, pacing is applied to a region remote from the vulnerable region in order to produce a conditioning effect.