title: Influence of cyclic variation of right ventricular volume on left ventricular mechanical parameters measured with conductance catheter.
abstract: The conductance catheter is widely used for the continuous measurement of the left ventricular (LV) pressure-volume loops. Cyclical change of the right ventricular (RV) volume may alter the parallel conductance volume, thereby affecting the LV mechanical parameters. Using 8 open-chest adult mongrel dogs, multiple LV pressure-volume loops were obtained by 2 methods: first with a vena cava occlusion (VCO) method, which involved RV volume alteration, and second with a right-heart-bypass (RHB) preparation, which decompressed the right ventricle completely. The slope of the end-systolic pressure-volume relation (Ees), the end-systolic volume associated with the end-systolic pressure of 100 mmHg (V100,es), stiffness constant (beta), and the end-diastolic volume associated with the end-diastolic pressure of 9 mmHg (V9,ed) were calculated from each loop. There was minimal influence from RV volume alteration on systolic-phase indices [Ees (VCO method, 6.37 +/- 1.91 mmHg/ml; RHB preparation, 6.60 +/- 1.66mmHg/ml; p=0.356), and V100,es (VCO method, 18.4 +/- 9.3ml; RHB preparation, 17.8 +/- 9.0 ml; p=0.681)], but there was a significant influence on diastolic-phase indices [beta (VCO method, 0.0599 +/- 0.0152; RHB preparation, 0.0839 +/- 0.0150; p=0.007), and V9,ed (VCO method, 35.6 +/- 11.3 ml; RHB preparation, 31.9 +/- 12.3 ml; p=0.001)]. The increase in the RV volume in the diastolic phase increased the parallel conductance volume, causing overestimation of the LV diastolic volume measured by the conductance catheter.
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tanoue
authors.forename: S
authors.initials: S
authors.lastname: Morita
authors.forename: M
authors.initials: M
authors.lastname: Hisahara
authors.forename: R
authors.initials: R
authors.lastname: Tominaga
authors.forename: Y
authors.initials: Y
authors.lastname: Kawachi
authors.forename: H
authors.initials: H
authors.lastname: Yasui
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization; D002306:Cardiac Volume / Q000502:physiology*; D003971:Diastole; D004285:Dogs; D004553:Electric Conductivity; D016277:Ventricular Function, Left / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*