Purpose: To study the coronary resistance reserve on the reperfused myocardium, damaged by 15 minutes of severe ischemia.
Material and methods: Eight mongrel dogs, of either sex, weighing 14.4 to 21 kg were used. The index studied was the late diastolic coronary resistance. The coronary reserve was studied through reactive hyperemia produced by 10 seconds of coronary occlusion in the 5, 10, 15 and 20 minutes of reperfusion. Histological studies were done in the reperfused and control areas.
Results: The myocardial structure in the reperfused area was essentially normal, without any lesion on the capillaries or intra-myocardial vessels. The diastolic coronary resistance, after reactive hyperemia, during the reperfusion 20 minutes, have no differences with the control values. The coronary resistances in the reperfusion time, improved progressively until normal control, considering the perfusion pressure.
Conclusion: The coronary vascular reserve is preserved after 15 minutes of ischemia, followed by 20 minutes of reperfusion, considering the perfusion pressure.