Campbell K B, Taheri H, Kirkpatrick R D, Slinker B K
Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman 99164-6520.
Am J Physiol. 1992 Jun;262(6 Pt 2):H1631-9. doi: 10.1152/ajpheart.1992.262.6.H1631.
Single-beat and steady-state techniques for evaluating end-systolic pressure-volume relationship (ESPVR) and Frank-Starling mechanism (FSM) in the crystalloid-perfused isolated rabbit heart were compared. In the single-beat technique, a train of stable isovolumic beats was interrupted with a single perturbed beat that either ejected against various levels of imposed isobaric load (ESPVR protocol) or beat isovolumically against various levels of end-diastolic volume (V(ED); FSM protocol). In steady-state technique, sustained beating was established, isobarically, at each of various loads (ESPVR protocol) or, isovolumically, at each of various V(ED) values (FSM protocol). ESPVR from steady-state technique lay above and to the left of that from single-beat technique. Contractile state was not uniform within steady-state technique, whereas it was uniform within single-beat technique. In the FSM protocol, single-beat technique exhibited the following features relative to steady-state technique: 1) greater range of developed pressures, 2) steeper ascending limb and more sharply defined maxima, 3) higher maximal developed pressure (Pdmax), and 4) greater volume at Pdmax(Vmax). Again. a common contractile state existed within single-beat technique but not within steady-state technique. It was concluded that single-beat technique was preferable to steady-state technique for evaluating ESPVR and FSM because 1) single-beat technique required less time for obtaining data, 2) single-beat technique allowed identification of uncomplicated values of Pdmax and Vmax, and 3) single-beat technique provided a common contractile-state reference for all data, whereas steady-state technique did not.
比较了评估晶体灌注离体兔心的收缩末期压力-容积关系（ESPVR）和Frank-Starling机制（FSM）的单搏技术和稳态技术。在单搏技术中，一系列稳定的等容搏动被一个受干扰的单搏打断，该受干扰单搏要么在不同水平的外加等压负荷下射血（ESPVR方案），要么在不同水平的舒张末期容积（V(ED)）下等容搏动（FSM方案）。在稳态技术中，在不同负荷下等压建立持续搏动（ESPVR方案），或者在不同V(ED)值下等容建立持续搏动（FSM方案）。稳态技术得到的ESPVR位于单搏技术得到的ESPVR的上方和左侧。稳态技术中的收缩状态不均匀，而单搏技术中的收缩状态均匀。在FSM方案中，相对于稳态技术，单搏技术表现出以下特征：1）更大的压力上升范围，2）上升支更陡且最大值更清晰，3）更高的最大压力上升值（Pdmax），4）Pdmax时的容积更大（Vmax）。同样，单搏技术中有共同的收缩状态，而稳态技术中没有。得出结论，在评估ESPVR和FSM方面，单搏技术优于稳态技术，因为1）单搏技术获取数据所需时间更少，2）单搏技术能够识别Pdmax和Vmax的简单值，3）单搏技术为所有数据提供了共同的收缩状态参考，而稳态技术则没有。
