Estimation of left ventricular filling pressure by Doppler echocardiography in dogs with pacing-induced heart failure.
BACKGROUND
Congestive heart failure (CHF) is a common clinical syndrome characterized by elevated filling pressure.


OBJECTIVE
Doppler echocardiographic (DE) variables of left ventricular (LV) filling can predict a decline of LV end-diastolic pressure (LVEDP) induced by acute preload reduction in dogs with compensated CHF.


METHODS
Five male hound dogs.


METHODS
Dogs previously instrumented with a transvenous cardiac pacemaker and a LV pressure gauge were paced at 160-180 bpm to induce mild CHF characterized by LVEDP > 20 mmHg. LVEDP and 9 DE variables of LV filling derived from diastolic time intervals, transmitral and pulmonary venous flow, and tissue Doppler imaging were measured simultaneously at baseline and 30, 60, 120, and 240 minutes after furosemide (4 mg/kg, IV) or placebo (0.9% saline, IV). Repeated measures analysis of variance and correlation analysis were used to determine the association between the decline of LVEDP after furosemide and DE measures of LV filling pressure (LVFP).


RESULTS
Furosemide but not placebo decreased LVEDP (P < .001). The ratio of early transmitral flow velocity to LV isovolumic relaxation time (E : IVRT) predicted LVEDP best (R(2)= .50; P < .001). Correlations were also found between LVEDP and IVRT, E, ratio between E and late diastolic transmitral flow velocity (E : A), and early diastolic velocity of the mitral annulus (Ea). The ratio of E to Ea (E : Ea) was not useful in the prediction of LVEDP in this model.


CONCLUSIONS
E : IVRT can be used to predict LVFP in dogs with mild left-sided CHF induced by rapid pacing.
Schober
K E
KE
Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH 43210, USA. schober.4@osu.edu
Stern
J A
JA
DaCunha
D N Q T
DN
Pedraza-Toscano
A M
AM
Shemanski
D
D
Hamlin
R L
RL
D000818:Animals; D002304:Cardiac Pacing, Artificial; D004283:Dog Diseases / Q000000981:diagnostic imaging*; D004285:Dogs; D015150:Echocardiography, Doppler / Q000662:veterinary*; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology / Q000662:veterinary*; D008297:Male; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology*; D017725:Ventricular Pressure / Q000502:physiology*