title: Development of a servo pump system for in vivo loading of pathological pulmonary artery impedance on the right ventricle of normal rats.
abstract: Pulmonary artery (PA) impedance provides detailed information on right ventricular (RV) afterload in pulmonary hypertension (PH). This study aimed to examine PA impedance in a rat model of monocrotaline-induced PH (MCT-PH) and to develop an experimental system for in vivo loading of pathological PA impedance on the RV of normal rats. PA impedance was quantified in normal (n= 10) and MCT-PH rats (n= 10) using a three-element Windkessel (3-WK) model. Compared with normal rats, MCT-PH rats had higher characteristic impedance (ZC) and peripheral pulmonary resistance (RP) (ZC: 0.121 ± 0.039 vs. 0.053 ± 0.017 mmHg·min·ml(-1), P< 0.001; RP: 0.581 ± 0.334 vs. 0.252 ± 0.105 mmHg·min·ml(-1), P= 0.013) and lower pulmonary artery compliance (CP) (0.242 ± 0.131 vs. 0.700 ± 0.186 ml/mmHg, P< 0.001). In another group of 10 normal rats, a computer-controlled servo pump was connected to the left PA for loading PA impedance with parameters in pathological ranges designed by the 3-WK model. Activation of the servo pump decreased the error of measured vs. target PA impedance (modulus: from 0.047 ± 0.020 without pump activation to 0.019 ± 0.007 with pump activation,P< 0.001; phase: 0.085 ± 0.028 to 0.043 ± 0.012 radians,P< 0.001). In conclusion, MCT-PH increases ZC and RP and decreases CP Our servo pump system, which is capable of imposing arbitrary PA impedance with pathological parameters, may offer a unique opportunity to delineate the pathological significance of PA impedance in PH.
authors.affiliation: Department of Artificial Organ Medicine, Faculty of Medicine, Osaka University Graduate School of Medicine, Osaka, Japan; Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Fukumitsu
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kawada
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Turner
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Uemura
authors.affiliation: Department of Artificial Organ Medicine, Faculty of Medicine, Osaka University Graduate School of Medicine, Osaka, Japan; Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan su91mach@ncvc.go.jp.
authors.forename: Masaru
authors.initials: M
authors.lastname: Sugimachi
mesh_terms: D000818:Animals; D062186:Arterial Pressure; D001783:Blood Flow Velocity; D002304:Cardiac Pacing, Artificial; D004195:Disease Models, Animal; D004582:Electronics, Medical; D004867:Equipment Design; D006439:Hemodynamics; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D008955:Models, Cardiovascular; D016686:Monocrotaline; D011651:Pulmonary Artery / Q000503:physiopathology*; D011652:Pulmonary Circulation; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D013997:Time Factors; D014655:Vascular Resistance; D016278:Ventricular Function, Right
chemical_list: D016686:Monocrotaline
keywords: monocrotaline; pulmonary artery impedance; pulmonary hypertension; windkessel model