title: Experimental and numerically modeled effects of altered loading conditions on pulmonary venous flow and left atrial pressure in patients with mitral regurgitation.
abstract: Pulmonary venous flow measured by pulsed-wave Doppler transesophageal echocardiography reflects the effects of mitral regurgitation on left atrial pressure contour. To assess the relationship between pulmonary venous flow and left atrial pressure in patients with mitral regurgitation under altered loading conditions, we studied 25 patients with 3+ or 4+ mitral regurgitation and a control group by measuring pulmonary venous flow with transesophageal echocardiography and left atrial pressures after administering saline solution (n = 6), nitroglycerin (n = 6), phenylephrine (n = 6), or nitroprusside (n = 7). After administration, the left atrial pressure v wave increased in the group given phenylephrine, concomitant with an increased diastolic flow. In contrast, the left atrial pressure v wave decreased in the group given nitroglycerin, concomitant with a decreased diastolic flow. Changes in diastolic flow were closely related to changes in the left atrial pressure v wave under all loading conditions (r = 0.91; p < 0.0001). Numeric modeling of left atrial pressure and pulmonary venous diastolic flow corroborated the experimental findings. We conclude that changes in pulmonary venous diastolic flow are closely related to changes in the left atrial pressure v wave in mitral regurgitation, under altered loading conditions.
authors.affiliation: Department of Cardiology, Cleveland Clinic Foundation, OH 44195, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Klein
authors.forename: R M
authors.initials: RM
authors.lastname: Savage
authors.forename: F
authors.initials: F
authors.lastname: Kahan
authors.forename: R D
authors.initials: RD
authors.lastname: Murray
authors.forename: J D
authors.initials: JD
authors.lastname: Thomas
authors.forename: W J
authors.initials: WJ
authors.lastname: Stewart
authors.forename: M
authors.initials: M
authors.lastname: Piedmonte
authors.forename: P M
authors.initials: PM
authors.lastname: McCarthy
authors.forename: D M
authors.initials: DM
authors.lastname: Cosgrove
mesh_terms: D000328:Adult; D000368:Aged; D016280:Atrial Function, Right / Q000187:drug effects; D001783:Blood Flow Velocity / Q000187:drug effects; D003971:Diastole; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008955:Models, Cardiovascular; D005996:Nitroglycerin / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011667:Pulmonary Veins / Q000503:physiopathology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D014662:Vasoconstrictor Agents; D009599:Nitroprusside; D010656:Phenylephrine; D005996:Nitroglycerin