<原著>心筋反応性充血時の冠血管抵抗と冠閉塞時間との関係

概要

論文の詳細を見る
Coronary vascular bed dilates markedly by myocardial ischemia to meet myocardial oxygen demand. However, there is a possibility that coronary flow might decrease by ischemia if there exists severe coronary obstruction. To assess this concept, the left anterior descending coronary artery was perfused with own arterial blood at a constant flow rate while measuring perfusion pressure in 12 mongrel open-chest dogs. Myocardial reactive hyperemia was induced by the temporary cessation of coronary perfusion. Duration of the flow cessation ranged from 20 seconds to 5 minutes to induce various degrees of reactive hyperemia. The coronary perfusion pressure after reperfusion was measured to calculate the coronary vascular resistance during myocardial ischemia. Coronary perfusion pressure was markedly decreased during reactive hyperemia in all of 25 experiments, if the cessation of flow was relatively short (from 20 to 90 seconds). Calculated coronary vascular resistance 30 seconds after reperfusion was decreased to 86±2% of the control, indicating coronary vascular bed dilated considerably by ischemia. While in 19 experiments where the cessation of coronary perfusion was 2 to 5 minutes, the reduction of coronary vascular resistance 30 seconds after the initiation of perfusion almost disappeared, the coronary vascular resistance reached 98±2% of the control. In 8 out of these 19 experiments, the myocardial ischemia caused by reactive hyperemia induced a transient increase of coronary vascular resistance. These indicated that more prolonged ischemia caused a less pronounced reduction in coronary vascular resistance. The present study indicates that coronary vascular bed will dilate considerably by transient myocardial ischemia. However, more prolonged and possibly more profound myocardial ischemia will paradoxically reduce the coronary vasodilatation.
近畿大学の論文
1983-09-25

<原著>心筋反応性充血時の冠血管抵抗と冠閉塞時間との関係

スポンサーリンク

概要

著者

関連論文

スポンサーリンク