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Figure 5 Coronary resistance at the level of epicardial stenosis (top) and in distal microcirculation (middle) at the various steps of the protocol as indicated in Figure 1. Bottom panel shows the behavior of total coronary resistance and the contribution of stenosis (black) and microvascular resistance (white columns). Coronary resistance was not calculated during balloon coronary occlusion. During ischemia, both coronary stenosis and distal microcirculation showed a significant increase in resistance to flow (* = p < 0.05 vs. baseline, = p < 0.05 vs. adenosine; = p < 0.05 vs. max ischemia).