Abstract
Objective—To compare Doppler echocardiographic variables of left ventricular (LV) function with those obtained invasively via cardiac catheterization under a range of hemodynamic conditions.
Animals—7 healthy anesthetized cats (1 to 3 years of age).
Procedure—Cats were anesthetized and instrumented
to measure the time constant of isovolumic
relaxation (tau [
]), LV end-diastolic pressure
(LVEDP), peak negative and positive rate of change
of LV pressure, arterial blood pressure, and cardiac
output. Echocardiographic variables of diastolic function
(isovolumic relaxation time [IVRT], early LV flow
propagation velocity [Vp], transmitral and pulmonary
venous flow velocity indices, and LV tissue Doppler
imaging indices) were measured simultaneously
over a range of hemodynamic states induced by
treatments with esmolol, dobutamine, cilobradine,
and volume loading. Correlation between invasive
and noninvasive measures of LV filling was determined
by univariate and multivariate regression
analyses.
Results—Significant correlations were found
between and IVRT, peak Vp, peak late transmitral
flow velocity, and peak systolic pulmonary venous
flow velocity. A significant correlation was found
between LVEDP and early diastolic transmitral flow
velocity (peak E) and the ratio of peak E to peak Vp,
but not between LVEDP and peak Vp.
Conclusion and Clinical Relevance—IVRT and Vp can be used as noninvasive indices of LV relaxation; Vp was independent of preload and heart rate in this study. The E:Vp ratio may be useful as an indicator of LV filling pressure. (Am J Vet Res 2003;64:93–103)
