Pulmonary blood volume in mitral regurgitation in Cavalier King Charles spaniels.
BACKGROUND
Pulmonary edema and venous congestion are well-recognized signs of congestive heart failure (CHF) in advanced canine chronic mitral regurgitation (MR). However, little is known about pulmonary blood volume (PBV), blood pulmonary transit time (PTT), and the regulation of these.


OBJECTIVE
To measure and evaluate the relationships of PBV, forward stroke volume (FSV), and heart rate normalized blood pulmonary transit time (nPTT) in healthy dogs and dogs with MR.


METHODS
Thirty-three Cavalier King Charles Spaniels; 11 healthy, 4 in modified New York Heart Association (NYHA) class I, 11 in class II, and 7 in CHF.


METHODS
Heart rate normalized PTTs were measured by radionuclide angiocardiography. Left ventricular end diastolic and systolic diameter, left atrial/aortic root ratio, and FSV were measured by echocardiography. PBV and pulmonary blood volume index (PBVI) were calculated by established formulas.


RESULTS
PBVI was 308±56 (mean±SD) mL/m2 for healthy dogs, 287±51 mL/m2 in NYHA class I, 360±66 mL/m2 in Class II, and 623±232 mL/m2 in CHF (P=.0008). Heart rate normalized PTT, not FSV, was a predictor of PBV (r=0.92 and 0.02, respectively).


CONCLUSIONS
Increased PBV, not decreased FSV, is the main cause of increased nPTT in MR. Increased nPTT can be used as an indicator of abnormal cardiopulmonary function in dogs with MR.
Eriksson
A
A
Minerva Institute for Medical Research, University of Helsinki, Helsinki, Finland. anders.eriksson@helsinki.fi
Hansson
K
K
Häggström
J
J
Järvinen
A-K
AK
Lord
P
P
D000818:Animals; D001810:Blood Volume; D004283:Dog Diseases / Q000503:physiopathology*; D004285:Dogs; D005260:Female; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008944:Mitral Valve Insufficiency / Q000145:classification / Q000503:physiopathology / Q000662:veterinary*; D011654:Pulmonary Edema / Q000503:physiopathology / Q000662:veterinary*