In vitro negative inotropic effect of plasma collected at the time of reperfusion in humans undergoing liver transplantation

Abstract

Background: During orthotopic liver transplantation (OLT), acute depression of myocardial contractility has been suspected at the time of the graft reperfusion. Methods: The authors tested the hypothesis that plasma collected at the time of reperfusion in OLT patients exerted a negative inotropic effect on isolated rat myocardium. Plasma from 13 OLT patients was collected either before surgical incision (group 1, n = 8) or 3-5 min after vena cava and portal vein unclamping (group 2, n = 9). Six patients had their pre-and postincision plasma analyzed. A postreperfusion syndrome was observed in 3 of 13 patients. Left ventricular rat papillary muscles were studied at baseline (T0), 30 min after the addition of plasma (T30), and 60 min after the addition of plasma (T60). The authors recorded contraction parameters (maximum unloaded shortening velocity [Vmax], peak extent of systolic shortening at preload [ΔL], maximum active isometric tension [AFi], positive peak tension derivative [+dFi/dt], time-to-peak shortening [TPS], and time- to-peak force [TPF]) and relaxation parameters (maximum lengthening velocity at preload [VI], negative peak tension derivative [-dFi/dt], index of load sensitivity of relaxation [tRi]). Results: In group 1, contraction parameters remained unchanged, with the exception of a decreased Vmax at T30 and AFi at T60 (each P<0.05). In group 2, all contraction parameters were significantly decreased at T30 and at T60, with the exception of AFi at T60. Both types of plasma decreased VI and altered tRi at T30 and T60, whereas only reperfusion plasma decreased -dFi/dt at T30 and T60. At T30, ΔL, -dFi/dt, and tRi were significantly more impaired in group 2 than in group 1. There was no relationship between inotropic changes and mean arterial pressure decrease at the time of reperfusion. Conclusion: Plasma collected at the time of graft reperfusion in OLT patients exerted negative effects on contraction and relaxation performance in isolated rat left ventricular papillary muscle.