Lambert C R, de Marchena E J, Bikkina M, Arcement B K
Division of Cardiology, University of South Alabama College of Medicine, Mobile, USA.
Clin Cardiol. 1996 Jun;19(6):461-5. doi: 10.1002/clc.4960190604.
Carbon dioxide is currently used as an arterial and venous contrast agent; however, little is known of its effects on left ventricular function. This study was undertaken to investigate those effects.
Ascending doses of 5, 10, and 20 ml of carbon dioxide were administered into the left main coronary artery of domestic swine with and without a continuous infusion of intravenous nitroglycerin (50 micrograms/min).
Carbon dioxide had an immediate and profound depressant effect on both systolic and diastolic left ventricular function associated with ischemic electrocardiographic changes. Compared with controls (% change), ascending doses of carbon dioxide decreased systolic pressure by -35 +/- 7, -48 +/- 8, and -53 +/- 4 in the absence of nitroglycerin, and by -32 +/- 9, -50 +/- 9, and -60 +/- 9 in the presence of nitroglycerin. Peak+dP/dt decreased by -54 +/- 7, -61 +/- 11, and -64 +/- 3 in the absence of nitroglycerin, and by -36 +/- 13, -55 +/- 11, and -65 +/- 11 in the presence of nitroglycerin. Minimum -dP/dt increased by 65 +/- 8,71 +/- 8, and 77 +/- 3 in the absence of nitroglycerin, and by 63 +/- 7,71 +/- 8, and 78 +/- 7 in the presence of nitroglycerin. No significant changes in heart rate were observed; however, widespread ST-segment elevation was observed in all animals. Coronary angiography following carbon dioxide injection revealed a marked decrease in coronary flow velocity until the gas was cleared from the microcirculation. This was also documented by direct measurement of flow velocity using a Doppler catheter in an additional animal. Left ventriculography demonstrated immediate global dilation and depression of systolic function.
In the swine model, relatively small doses of intracoronary carbon dioxide cause profound yet reversible global left ventricular dysfunction which appears to be ischemic in origin.
二氧化碳目前用作动脉和静脉造影剂；然而，其对左心室功能的影响却知之甚少。本研究旨在调查这些影响。
分别向家猪的左冠状动脉内注入递增剂量的5、10和20毫升二氧化碳，分为持续静脉输注硝酸甘油（50微克/分钟）组和未输注硝酸甘油组。
二氧化碳对左心室的收缩和舒张功能均有即刻且显著的抑制作用，并伴有缺血性心电图改变。与对照组相比（变化百分比），在未使用硝酸甘油时，递增剂量的二氧化碳使收缩压分别降低-35±7、-48±8和-53±4，在使用硝酸甘油时分别降低-32±9、-50±9和-60±9。在未使用硝酸甘油时，dp/dt峰值分别降低-54±7、-61±11和-64±3，在使用硝酸甘油时分别降低-36±13、-55±11和-65±11。最低-dp/dt在未使用硝酸甘油时分别升高65±8、71±8和77±3，在使用硝酸甘油时分别升高63±7、71±8和78±7。未观察到心率有显著变化；然而，所有动物均出现广泛的ST段抬高。注入二氧化碳后进行冠状动脉造影显示，在气体从微循环清除之前，冠状动脉血流速度显著降低。在另一只动物中使用多普勒导管直接测量血流速度也证实了这一点。左心室造影显示即刻出现全心扩大和收缩功能抑制。
在家猪模型中，相对小剂量的冠状动脉内注入二氧化碳会导致严重但可逆的全心左心室功能障碍，其起源似乎是缺血性的。
