Pinto F J, St Goar F G, Fischell T A, Stadius M L, Valantine H A, Alderman E L, Popp R L
Stanford University School of Medicine, Division of Cardiovascular Medicine, CA 94305.
Circulation. 1992 Jan;85(1):69-77. doi: 10.1161/01.cir.85.1.69.
Coronary artery vasomotion is altered after cardiac transplantation. The impact of accelerated transplant coronary atherosclerosis and myocardial rejection on vasomotion is not well understood. Intravascular ultrasound is a new imaging method with the ability to study real-time changes in coronary artery dimensions.
Epicardial coronary artery response to nitroglycerin was studied in 32 cardiac transplant recipients (age, 47 +/- 11 years) 3 weeks to 10 years after transplantation with intracoronary ultrasound. Cross-sectional luminal area and diameter were measured at a fixed position in the left anterior descending artery immediately before and every 30 seconds for 5 minutes after 0.4 mg of sublingual nitroglycerin. Cross-sectional area increased from a baseline of 13.1 +/- 3.9 mm2 to 15.8 +/- 3.9 mm2 at maximal vasodilation; luminal diameter increased from 4.0 +/- 0.6 mm to 4.5 +/- 0.6 mm. This increase reached statistical significance (p less than 0.001) at 1.5 minutes after administration of nitroglycerin; mean maximum increase occurred at 4.5 minutes (24% for cross-sectional area and 11% for luminal diameter). Patients with biopsy-proven mild or moderate concurrent rejection had a significantly blunted vasodilatory response versus the nonrejection group (9% versus 27% for cross-sectional area, p less than 0.04), although a vasodilatory effect was still present. Nitroglycerin response was well preserved in patients up to 10 years after transplantation; however, there was a trend toward a decreased response in patients studied immediately after transplantation (21% versus 29%, p = 0.37). Coronary intimal thickness, as measured by ultrasound, had no impact on the vasodilatory response (R = 0.23, p = 0.34).
Vasodilatory response to nitroglycerin in cardiac transplant recipients is attenuated during episodes of cardiac rejection. This response is preserved in long-term survivors and is independent of the degree of intimal thickening. Intravascular ultrasound provides a new method to document real-time epicardial coronary vasomotion.
心脏移植后冠状动脉血管舒缩功能发生改变。加速性移植冠状动脉粥样硬化和心肌排斥反应对血管舒缩功能的影响尚不清楚。血管内超声是一种能够研究冠状动脉尺寸实时变化的新成像方法。
采用冠状动脉内超声研究了32例心脏移植受者（年龄47±11岁）在移植后3周~10年内心外膜冠状动脉对硝酸甘油的反应。在舌下含服0.4mg硝酸甘油前及含服后每30秒测量左前降支固定位置处的横断面管腔面积和直径，共测量5分钟。最大血管舒张时，横断面面积从基线的13.1±3.9mm²增加到15.8±3.9mm²；管腔直径从4.0±0.6mm增加到4.5±0.6mm。硝酸甘油给药后1.5分钟时，这种增加具有统计学意义（p<0.001）；平均最大增加出现在4.5分钟时（横断面面积增加24%，管腔直径增加11%）。经活检证实有轻度或中度并发排斥反应的患者与无排斥反应组相比，其血管舒张反应明显减弱（横断面面积增加9%对27%，p<0.04），尽管仍存在血管舒张效应。移植后长达10年的患者中硝酸甘油反应保存良好；然而，移植后立即研究的患者有反应降低的趋势（21%对29%，p=0.37）。超声测量的冠状动脉内膜厚度对血管舒张反应无影响（R=0.23，p=0.34）。
心脏移植受者在心脏排斥发作期间对硝酸甘油的血管舒张反应减弱。这种反应在长期存活者中得以保留，且与内膜增厚程度无关。血管内超声提供了一种记录心外膜冠状动脉实时血管舒缩功能的新方法。
