Veterinary Teaching Hospital, Kansas State University, Manhattan, KS.
Echocardiographic Estimation of Mean Left Atrial Pressure in a Canine Model of Acute Mitral Valve Insufficiency
Version of Record online: 5 FEB 2008
© 2004 American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 18, Issue 5, pages 667–672, September 2004
How to Cite
Oyama, M. A., Sisson, D. D., Bulmer, B. J. and Constable, P. D. (2004), Echocardiographic Estimation of Mean Left Atrial Pressure in a Canine Model of Acute Mitral Valve Insufficiency. Journal of Veterinary Internal Medicine, 18: 667–672. doi: 10.1111/j.1939-1676.2004.tb02604.x
Preliminary data were presented at the Annual Scientific Session of the American College of Cardiology, Chicago, IL, March 30–April 2, 2003.
- Issue online: 5 FEB 2008
- Version of Record online: 5 FEB 2008
- Revised March 4, 2004; Accepted April 6, 2004
- Filling pressure;
- Mitral regurgitation;
- Tissue Doppler
High mean left atrial pressure (MLAP) due to canine degenerative mitral valve disease is associated with clinically relevant morbidity and mortality. The ability to noninvasively measure MLAP would assist in the diagnosis and treatment of disease. Doppler echocardiography allows measurement of early transmitral blood flow (E) and the velocity of the mitral valve annulus (Ea). The ratio of early mitral inflow velocity to early mitral annular velocity (E: Ea) correlates well with MLAP in human subjects. We sought to determine the ability of E: Ea to predict MLAP in dogs with experimentally induced mitral regurgitation. Nine anesthetized purpose-bred dogs underwent placement of a Swan-Ganz catheter into the left atrium and recording of MLAP. Simultaneous transthoracic echocardiographic and hemodynamic studies were performed after acute chordae tendineae rupture and during IV infusion with nitroprusside (2.5-5.0 μg?kg-1?min-1) or hydralazine (1-1.5 mg/kg). Mitral regurgitant fraction, measured by single-plane angiography and thermodilution, ranged from 17% to 81%. MLAP increased from 5.4 ± 2.5 mm Hg to 17.4 ± 9.4 mm Hg after creation of mitral valve regurgitation (MR; P= .018). Forty sets of echocardiographic measurements were obtained from 7 dogs, and E, as well as E: Ea, were linearly related to MLAP. The R2 value for the linear regression equation containing E: Ea as the dependent variable (0.83) was greater than that for E (0.73). The 95% confidence intervals were calculated for predicting MLAP = 20 mm Hg from E:Ea, and E:Ea > 9.1 or < 6.0 indicated a 95% probability that MLAP was ≥ 20 mm Hg or ≤20 mm Hg, respectively. Echocardiography can be used to predict MLAP in isoflurane-anesthetized dogs with experimentally induced acute mitral valve insufficiency.