It is important to obtain an accurate quantification of mitral regurgitation severity. This fact is especially important in order to identify B2 patients - ACVIM classification - that can benefit from starting medication or to prevent congestive heart failure. The vena contracta is the narrowest portion of a jet downstream from the regurgitant orifice. The objective of the present study is to prove if the vena contracta could be used as criteria for classification in dogs with DCMVD. One hundred and thirteen dogs suffering from DCMVD in different phases according to ACVIM classification, have been included: B1, n=54; B2, n=51 and C, n=8. The vena contracta was measured from the parasternal left apical four-chamber long axis view. Three measurements were obtained for each dog and the average was obtained. The results showed a statistically significant difference between stages for end-diastolic left ventricular index (EDVI), end-sistolic left ventricular index (ESVI) and vena contracta (Kruskal-Wallis for independent samples test). The differences were significant between B1 dogs and B2 dogs (p=0.022) and between B1 and C dogs (p=0.035) for vena contracta. The differences were significant between B1 dogs and B2 dogs (p<0.0001) and between B1 and C dogs (p<0.001) for EDVI. The differences were significant between B1 dogs and B2 dogs (p=0.044) and between B1 and C dogs (p=0.032) for ESVI. There were no differences for these values between B2 and C dogs. The vena contracta appears to be useful to differentiate between early phases of DCMVD and congestive phase of DCMVD but it seems less useful to differentiate between B2 dogs and C dogs. It is important to remember that this measurement is not useful if multiple jets are present, which is common in dogs with DCMVD. The vena contracta has an ellipsoidal shape so the measurements could vary depending on the plane of acquisition. Due to the fact that the vena contracta usually is small (typically less than 0.5 cm), slight measurement errors could lead to large mistakes and misclassifications. In humans, it is recommended to measure the vena contracta from the right parasternal long axis. All of these factors must be taken into consideration from a critical point of view in the face of the present results.

Disclosures

No disclosures to report.