Falck G, Olsen H, Jynge P
University of Trondheim, Faculty of Medicine, Department of Pharmacology and Toxicology, Norway.
Acad Radiol. 1997 Apr;4(4):253-63. doi: 10.1016/s1076-6332(97)80025-6.
The purpose of this study was to evaluate the role of biophysical factors (viscosity, temperature, osmalality, perfusion pressure, and ionic washout) on cardiac contractility during coronary bolus perfusions.
Guinea pig hearts were perfused in the osmolality mode at constant and high flow (30 mL/min) and were subjected to boluses (injected in 1-8 seconds) of purely nonionic media: mannitol and iohexol (in hyposmolal, isosmolal, and twice isosmolal forms) and iodixanol (in a hyposmolal form).
All contrast media elicited a dose-dependent increase in aortic pressure and contractile variables that was attenuated by an increased osmolality. Elevation of aortic pressure was followed by an increase in left ventricular systolic pressure and, with iodixamol and iohexol, a subsequent elevation of left ventricular end-diastolic pressure. Moderate hypothermic solutions (29 degrees C) did not alter the responses. The ionic washout profile was the same for the three substances, as were the individual washout profiles for sodium, potassium, chloride, magnesium, and calcium.
An increase in osmolality attenuates the increased contractility induced by a purely nonionic medium. A viscosity-induced rise in perfusion pressure may increase contractility. A moderate reduction in bolus temperature does not alter the contractile responses. The ionic washout profile is the same for the main cardioactive electrolytes.
本研究旨在评估生物物理因素（粘度、温度、渗透压、灌注压力和离子洗脱）在冠状动脉团注灌注期间对心脏收缩力的作用。
豚鼠心脏在恒定高流量（30毫升/分钟）下以渗透压模式进行灌注，并接受纯非离子介质（甘露醇和碘海醇，分别为低渗、等渗和两倍等渗形式，以及碘克沙醇，低渗形式）的团注（在1至8秒内注射）。
所有造影剂均引起主动脉压力和收缩变量的剂量依赖性增加，渗透压升高会使其减弱。主动脉压力升高后，左心室收缩压升高，使用碘克沙醇和碘海醇时，随后左心室舒张末期压力升高。中度低温溶液（29摄氏度）并未改变这些反应。三种物质的离子洗脱情况相同，钠、钾、氯、镁和钙的个体洗脱情况也相同。
渗透压升高会减弱纯非离子介质诱导的收缩力增加。粘度引起的灌注压力升高可能会增加收缩力。团注温度适度降低不会改变收缩反应。主要心脏活性电解质的离子洗脱情况相同。
