Rehr R B, Fuhs B E, Lee F, Tatum J L, Hirsch J I, Quint R
Department of Radiology, Medical College of Virginia.
Am Heart J. 1991 Dec;122(6):1571-82. doi: 10.1016/0002-8703(91)90273-k.
Thrombolytic therapy has increased the need for a technique to assess the viability of recently reperfused myocardium. This study examined the ability of in vivo phosphorus-31 (P-31) nuclear magnetic resonance (NMR) spectroscopy to distinguish reperfused-viable (stunned) from reperfused-infarcted myocardium at 6, 30, and 54 hours following coronary artery occlusion in a canine model. A 15-minute occlusion produced reperfused-viable myocardium in five animals and a 360-minute occlusion produced reperfused-infarcted myocardium in six animals. Postreperfusion risk zone myocardial phosphocreatine (PCr) concentration measured by P-31 NMR spectroscopy was significantly depressed throughout the 3-day study period in infarcted but not in viable myocardium (p less than 0.01 between groups, all time points). The postreperfusion ratio of inorganic phosphate (Pi) to PCr concentration, as determined by NMR spectroscopy, was elevated throughout the study period in infarcted but not in viable reperfused myocardium (p less than 0.01 between groups, all time points). Postreperfusion Pi concentration was elevated at 6 hours but not subsequently in reperfused-infarcted myocardium, and was not elevated in reperfused-viable myocardium. Logistic regression models selected PCr concentration and the Pi/PCr ratio as providing the best discrimination between reperfused-viable and reperfused-infarcted myocardium. The accuracy of P-31 NMR variables selected by logistic regression analysis for determining myocardial viability ranged from 97% to 100%.
溶栓治疗增加了对一种评估近期再灌注心肌存活能力技术的需求。本研究在犬模型中，检测了体内磷-31（P-31）核磁共振（NMR）波谱在冠状动脉闭塞后6小时、30小时和54小时区分再灌注存活（顿抑）心肌和再灌注梗死心肌的能力。15分钟的闭塞使5只动物产生了再灌注存活心肌，360分钟的闭塞使6只动物产生了再灌注梗死心肌。在整个3天的研究期间，通过P-31 NMR波谱测量的再灌注后危险区心肌磷酸肌酸（PCr）浓度在梗死心肌中显著降低，但在存活心肌中未降低（组间p<0.01，所有时间点）。通过NMR波谱测定的再灌注后无机磷酸盐（Pi）与PCr浓度之比在整个研究期间在梗死心肌中升高，但在再灌注存活心肌中未升高（组间p<0.01，所有时间点）。再灌注后Pi浓度在6小时时升高，但在再灌注梗死心肌中随后未升高，在再灌注存活心肌中也未升高。逻辑回归模型选择PCr浓度和Pi/PCr比值作为区分再灌注存活心肌和再灌注梗死心肌的最佳指标。通过逻辑回归分析选择的P-31 NMR变量用于确定心肌存活能力的准确性范围为97%至100%。
