Hemodynamics of different degrees of right heart bypass: experimental assessment.
BACKGROUND
Although their assessment could be of the utmost importance to determine the surgical treatment for patients with univentricular hearts, differences in ventricular performance between partial and complete right heart bypass remain to be defined.


METHODS
Three different degrees of right heart bypass were investigated in 5 mongrel dogs: (1) superior vena cava to both pulmonary arteries shunt (SCP); (2) inferior vena cava to both pulmonary arteries shunt (ICP); and (3) both venae cavae to both pulmonary arteries shunt (BCP). Hemodynamic studies included evaluation of the cardiac index and left atrial pressure as a function of the degree of right heart bypass.


RESULTS
By maintaining the mean left atrial pressure at 5 mm Hg, cardiac indexes were 1.98 +/- 0.25, 1.67 +/- 0.29, and 1.33 +/- 0.21 L.min-1.m-2 for SCP, ICP, and BCP shunts, respectively (p = 0.001). When keeping the cardiac index constant, mean left atrial pressures were 5.2 +/- 0.8, 5.5 +/- 0.9, and 7 +/- 0.7 mm Hg for SCP, ICP, and BCP shunts, respectively (p = 0.001).


CONCLUSIONS
Increasing degrees of right heart bypass are associated with a significant decrease in ventricular performance in this experimental model.
Department of Cardiovascular and Pediatric Cardiac Surgery, Marie Lannelongue Hospital, Paris-Sud University, Paris, France.
L
L
Macé
P
P
Dervanian
M
M
Weiss
J P
JP
Daniel
J
J
Losay
J Y
JY
Neveux
D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D018729:Fontan Procedure / Q000145:classification / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology; D016276:Ventricular Function / Q000502:physiology