Yagi Y, Goto K, Ooshima S, Takatsu H, Tsukamoto T, Iida M, Yamamoto N, Deguchi F, Terashima Y, Hirakawa S
Second Department of Internal Medicine, Gifu University School of Medicine.
J Cardiol. 1989 Sep;19(3):921-31.
In the present study, we constructed a left ventricular pressure-volume loop from catheterization data and RN-angiocardiography. By connecting the point of origin of the plane, not the point of Vd, with the end-systolic point of the loop, we calculated a "systolic" pressure-volume area (PVA), elastic potential energy (EPE), and stroke work (SW). A cardiac output (CO)-pulmonary artery wedge (PAW) pressure plot was constructed at rest and during exercise, using a bicycle ergometer, to evaluate cardiac pump function. End-systolic volume (ESV) was obtained from the left ventricular P-V loop, and the response of ESV to exercise was investigated. Thirty-five patients with various cardiac diseases were categorized in two groups according to the delta CO/delta PAW obtained from the shift of the CO-PAW plot during exercise; group I (n = 28) with the properly functioning hearts having the ratio greater than 0.12 l/min/mmHg and group II (n = 7) with the poorly functioning hearts having the ratio less than or equal to 0.12 l/min/mmHg. Group I was subdivided further into two subsets according to the changing pattern of ESV during exercise; group I-A with decreased or unchanged ESV (n = 20) and group I-B with increased ESV in which end-diastolic volume (EDV) was increased during exercise (n = 8). During exercise, PVA and SW were unchanged but SW/PVA increased in group I-A, suggesting improvement of external mechanical efficiency. SW/PVA was unchanged in group I-B, despite the increase in PVA and SW. This suggested that external mechanical work increased as a result of increased cardiac oxygen consumption. In group II, PVA increased, SW was unchanged and SW/PVA decreased, which could be explained by the mechanism that external mechanical work during exercise decreased as compared with that at rest. It was suggested that a different mechanism may have been responsible for the production of external mechanical work among patients in group I-A and in group I-B with properly functioning hearts judged from the CO-PAW plot. Therefore, it seems useful to calculate PVA, SW and SW/PVA during exercise using the left ventricular pressure-volume loop for evaluating cardiac function.
在本研究中，我们根据心导管检查数据和放射性核素心血管造影构建了左心室压力-容积环。通过连接平面的起始点而非舒张末期容积（Vd）点与环的收缩末期点，我们计算了“收缩期”压力-容积面积（PVA）、弹性势能（EPE）和每搏功（SW）。使用自行车测力计在静息和运动期间构建心输出量（CO）-肺动脉楔压（PAW）图，以评估心脏泵功能。从左心室压力-容积环获取收缩末期容积（ESV），并研究ESV对运动的反应。35例患有各种心脏病的患者根据运动期间CO-PAW图的变化所获得的ΔCO/ΔPAW分为两组；I组（n = 28）心脏功能正常，该比值大于0.12 l/min/mmHg，II组（n = 7）心脏功能不良，该比值小于或等于0.12 l/min/mmHg。I组根据运动期间ESV的变化模式进一步细分为两个亚组；I-A组ESV减少或不变（n = 20），I-B组ESV增加且运动期间舒张末期容积（EDV）增加（n = 8）。运动期间，I-A组PVA和SW不变，但SW/PVA增加，提示外部机械效率提高。I-B组尽管PVA和SW增加，但SW/PVA不变。这表明心脏氧耗增加导致外部机械功增加。II组PVA增加，SW不变，SW/PVA降低，这可以用运动期间外部机械功与静息时相比减少的机制来解释。从CO-PAW图判断，I-A组和心脏功能正常的I-B组患者产生外部机械功的机制可能不同。因此，利用左心室压力-容积环计算运动期间的PVA、SW和SW/PVA似乎有助于评估心脏功能。
