Numerical simulation of hemodynamic changes during beating-heart surgery: analysis of the effects of cardiac position alteration in an animal model.
Hemodynamic instability, mostly due to vertical lifting of the heart, is usually observed during beating-heart surgical procedures. However, some hemodynamic parameters, such as coronary blood flow, are not routinely measured. A digital computer model of the circulation able to simulate and analyze the effects of heart lifting and the Trendelenburg maneuver, and thus supply detailed hemodynamic information to the clinicians would provide a useful analytical tool. A lumped parameters model of the circulation was applied to both beta-blocked and not beta-blocked pigs. The results confirmed a drop of cardiac output and coronary flow during heart lifting and a rise of both variables after the Trendelenburg maneuver for beta-blocked animals. In not beta-blocked pigs, the analysis was more complex but the model reproduced experimental data and permitted coronary flow to be estimated. These results showed the feasibility of numerical simulation for specific circulatory conditions encountered during beating-heart surgery.
Ferrari
Gianfranco
G
National Council for Research, Institute of Clinical Physiology, Section of Rome, Rome, Italy. gfr.ferrari@ifc.cnr.it
De Lazzari
Claudio
C
de Kroon
Thom L
TL
Elstrodt
Jan M
JM
Rakhorst
Gerhard
G
Gu
Y John
YJ
D000818:Animals; D003198:Computer Simulation; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods / Q000662:veterinary*; D003326:Coronary Circulation; D018475:Head-Down Tilt; D006321:Heart / Q000503:physiopathology*; D023421:Models, Animal; D008954:Models, Biological; D013552:Swine; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right