Association between atrial fibrillation and right-sided manifestations of congestive heart failure in dogs with degenerative mitral valve disease or dilated cardiomyopathy.

INTRODUCTION

To determine whether dogs with atrial fibrillation (AF) are more likely to develop right-sided manifestations of congestive heart failure (R-CHF) than dogs without AF.

ANIMALS

Two hundred twenty dogs diagnosed with congestive heart failure (CHF) secondary to degenerative mitral valve disease (DMVD, n = 155) or dilated cardiomyopathy (DCM, n = 65) at a referral institution.

METHODS

Medical records were reviewed to extract relevant clinical and echocardiographic data.

RESULTS

Fifty dogs had AF at the time of CHF diagnosis, including 17/155 (11.0%) dogs with DMVD and 33/65 (50.8%) dogs with DCM. Sixty dogs had R-CHF evidenced by cavitary effusions. Among DMVD dogs, R-CHF occurred in 13/17 (76.5%) dogs with AF compared with 10/138 (7.2%) dogs without AF; among DCM dogs, R-CHF occurred in 24/33 (72.7%) dogs with AF compared with 13/32 (40.6%) dogs without AF. Dogs with AF were more likely to manifest R-CHF signs than dogs without AF (p < 0.0001 for DMVD; p = 0.0125 for DCM). The presence of AF, diagnosis of DCM, and moderate to severe tricuspid regurgitation were associated with R-CHF in multivariate analysis. AF was the strongest predictor of R-CHF (odds ratio, 14.44; 95% confidence interval, 5.75-36.26).

CONCLUSIONS

Dogs with AF are more likely to manifest R-CHF than dogs without AF. Cavitary effusions are an expected finding in approximately three-quarters of dogs with AF and CHF secondary to either DCM or DMVD.