Diagnostic accuracy of right pulmonary vein-to-pulmonary artery ratio to identify congestive heart failure in dogs affected by myxomatous mitral valve disease.

INTRODUCTION/

OBJECTIVES

Right pulmonary vein-to-right pulmonary artery (RPV/RPA) ratio, measured at the end of the T wave, helps identify congestive heart failure in dogs with myxomatous mitral valve disease (MMVD). The aim of this study was to investigate if RPV/RPA, measured at different time points during cardiac cycle, and RPV indexed to the aortic root (Ao) would help to identify MMVD dogs in stage C.

ANIMALS, MATERIALS AND

METHODS

Dogs affected by different stages of MMVD were prospectively enrolled in the present study. The RPV/RPA was measured at their maximum and minimum diameters, at the QRS and at the end of the T wave. The RPV and RPA measurements were indexed to the Ao.

RESULTS

The study included 58 dogs in stage B1, 38 in stage B2 and 59 in stage C. The RPV/RPA at the end of the T wave and at the maximum diameter detected dogs in stage C with a sensitivity of 96.6% and 94.9% and a specificity of 36.8% and 39.4%, respectively. The RPV at the end of the T wave-to-Ao ratio >1.07 presented the highest accuracy in identifying stage C dogs (sensitivity of 83.1%, and specificity of 71.1%).

STUDY LIMITATIONS: Potential misclassification of pulmonary hypertension and post-treatment evaluation could have introduced a measurement bias affecting diagnostic accuracy.

CONCLUSIONS

The RPV/RPA presented a low diagnostic accuracy in detecting stage C MMVD dogs, but RPV at the end of the T wave-to-Ao ratio, presented a higher diagnostic accuracy, which was not superior to left-atrial-to-aortic ratio.