[Intraoperative assessment of left ventricular function with left ventricular pressure-volume relationships in patients with open heart surgery].

: There are few reports on the assessment of the left ventricular function from left pressure-volume relationships intraoperatively in open heart surgery. LV Emax, Ea/Ees and EW/PVA efficiency were assessed intraoperatively by using a left ventricular conductance catheter in patients with aortocoronary bypass. After dobutamine administration (DOB, 10 micrograms/kg/min), LV Emax was increased by 33 +/- 23% during cardiopulmonary bypass (CPB) and 60 +/- 38% after weaning from CPB. Ea/Ees changed from 2.14 +/- 1.36 to 1.08 +/- 0.47 after weaning from CPB with dobutamine administration. EW/PVA efficiency changed from 52 +/- 12% to 66 +/- 10%. The change of LV Emax after dobutamine administration was correlated with the change of LV Emax after weaning from CPB and was correlated with Ea/Ees and EW/PVA efficiency after weaning from CPB. We concluded that measuring LV Emax before and after dobutamine administration during CPB is useful to assess left ventricular contraction clinically.