Abstract
Model-guided optimal treatment of hemodynamics is indispensable to improve outcome of acute heart failure patients. We constructed a comprehensive cardiovascular model by extending Guyton's model. The model enabled one to describe pathophysiology of unilateral left heart failure, often accompanying myocardial infarction. Venous return (VR) property was described by a surface instead of a curve, as a function of atrial pressures (PLA, PRA) as VR =V/W-GRPRA-GLPLA, given blood volume (V). The pumping ability of hearts was expressed by a cardiac output (CO) curve in 3D space, as CO=SL[ln(PLA-BL)+CL] =SR[ln(PRA-BR)+CR], given slopes of CO curve (S's). W, G's, B's and C's are parameters. Methods: Parameters W, G's, B's and C's were found to be relatively constant. In 8 dogs with/without acute heart failure, we determined V and S's from a single set of CO, PRA, PLA and standard parameter values. We then altered V from -8 to +8ml/kg and examined if predicted hemodynamics agreed those measured. Results: Standard parameters were identified as W(0.13), GR(19.6), GL (3.5). BL(2.1), CL(1.9), BR(2.0) and CR(0.80). Using these, we could accurately predict CO (y=0.93x+6.5, r2=0.96), PRA (y=0.87x+0.4, r2=0.91) and PLA (y=0.90x+0.48, r2=0.93). Conclusion: The proposed framework enabled one to accurately predict hemodynamics after volume intervention from a clinically available measurement, a single set of CO, PRA and PLA, and to optimize treatment of heart failure. [Jpn J Physiol 54 Suppl:S95 (2004)]
