Klocke F J, Koberstein R C, Pittman D E, Bunnell I L, Greene D G, Rosing D R
J Clin Invest. 1968 Dec;47(12):2711-24. doi: 10.1172/JCI105954.
The present investigation was intended to evaluate myocardial inert gas desaturation curves for manifestations of heterogeneous coronary perfusion. The test gas was hydrogen (H(2)) and blood H(2) analyses were performed with a gas chromatograph capable of detecting small but prolonged venous-arterial H(2) differences produced by areas of reduced flow. Curves were initially obtained after 4-min left ventricular infusions of H(2)-saturated saline in six patients with arteriographically proven coronary artery disease, three patients with normal coronary arteries, and nine closed-chest dogs. The dogs were studied before and after embolic occlusion of a portion of the left coronary artery. Although the slopes of their semilogarithmically plotted venous desaturation curves varied with time before embolization, they showed more distinct deviations from single exponentials after embolization (after H(2) concentrations had fallen below 15% of their initial values). The human curves divided similarly, those from coronary artery patients deviating appreciably from single exponentials. A similar separation was also evident in studies of coronary venous-arterial H(2) differences after 20 min of breathing 2% H(2): data were obtained in four dogs before and after coronary embolization, and in three normal patients, and five patients with coronary artery disease. Additional data indicated that the findings were not the result of right atrial admixture in sampled coronary venous blood, although admixture occurred frequently when blood was sampled in the first 2 cm of the coronary sinus (as seen in the frontal projection). Finally, average coronary flows calculated from a given set of data varied significantly with different methods of calculation. Areas of below-average flow seemed likely to be overlooked when single rate constants of desaturation, relatively insensitive analytical techniques, or relatively short periods of saturation and (or) desaturation are employed.
本研究旨在评估心肌惰性气体去饱和曲线，以了解冠状动脉灌注不均一性的表现。试验气体为氢气（H₂），采用能够检测因血流减少区域产生的微小但持续的静脉 - 动脉H₂差异的气相色谱仪进行血液H₂分析。最初，在6例经血管造影证实患有冠状动脉疾病的患者、3例冠状动脉正常的患者以及9只开胸犬中，经左心室输注H₂饱和盐水4分钟后获得曲线。对犬在左冠状动脉部分栓塞前后进行研究。尽管在栓塞前其半对数绘制的静脉去饱和曲线斜率随时间变化，但在栓塞后（H₂浓度降至初始值的15%以下后），它们与单指数曲线的偏差更为明显。人类的曲线也有类似的划分，冠状动脉疾病患者的曲线明显偏离单指数曲线。在呼吸2% H₂ 20分钟后对冠状动脉静脉 - 动脉H₂差异的研究中也有类似的分离现象：在4只犬冠状动脉栓塞前后、3例正常患者以及5例冠状动脉疾病患者中获取了数据。额外的数据表明，这些发现并非采样的冠状动脉静脉血中右心房混合的结果，尽管当在冠状窦前2厘米处采样血液时（如在额面投影中所见）混合现象经常发生。最后，根据给定数据集计算出的平均冠状动脉血流量因计算方法不同而有显著差异。当采用去饱和的单一速率常数、相对不敏感的分析技术或相对较短的饱和和（或）去饱和时间时，平均血流以下的区域似乎可能被忽视。
