An acute coronary occlusion with severe ischemic signs during percutaneous transluminal coronary angioplasty was successfully treated with a long balloon inflation. Subsequent balloon inflations did not produce ischemic signs. Distal coronary occlusion pressure rose significantly during balloon inflations of more than 2 min. It is hypothesized that an initial ischemic occlusion may improve tolerance to prolonged coronary occlusions. The underlying mechanism may be that further coronary collateral circulation is recruited over time.