<原著>心筋梗塞回復期における運動負荷ST上昇の機序に関する実験的研究

概要

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The exact mechanism behind exercise-induced ST-segment elevation in old myocardial infarction is still unknown. To clarify this problem, an experimental study on dogs was conducted. In 7 closed-chest dogs, transmural anterior wall infarction was induced by inserting a gelatin sponge embolus into the left anterior descending artery. One and 4 weeks following recovery, three interventions were performed : right atrial pacing (AP) alone, AP combined with noradrenaline (NA) infusion, and AP with methoxamine (MT) injection. ECG, LV angiogram, and blood pressure were taken. AP alone did not result in any ST changes, but AP+NA resulted in marked ST elevation. AP+MT again did not result in any ST changes, despite large increases in LVEDP. AP+NA significantly improved the LV ejection fraction, while AP+MT resulted in marked decreases. In the analysis of regional wall motion, AP+NA strongly enhanced radial shortenings in the non-infarcted area, but AP+MT reduced these shortenings. The wall motion of the infarcted area did not show any changes by the three interventions. These results suggest that ST-segment elevation may be a result of hyperkinesia of the non-infarcted areas, probably due to enhanced β-adrenergic activity in normal myocardial cells.
近畿大学の論文
1989-09-25