Case Studies In Small Animal

Cardiovascular Medicine

Case 12

Color Flow Doppler

This color flow Doppler image shows systolic flow from the right ventricle (RV) into the right atrium. Consequently, this dog has tricuspid regurgitation despite the absence of a systolic heart murmur. The jet is large and fills the right atrium suggesting that it is at least moderate if not severe. It is impossible to tell if the regurgitation in this dog is due to myxomatous valve degeneration or is secondary to the right ventricular chamber enlargement. Most likely it is due to both in this older medium-sized dog. LV, left ventricle. LA, left atrium.

This is a diastolic frame that shows a jet originating at the pulmonic valve and flowing back into the right ventricle (RV). Consequently, this is a jet of pulmonic regurgitation. The regurgitation in this dog is probably secondary to the thickened valve cusps as well as dilation of the pulmonic valve annulus. The jet is not large enough to create sound waves intense enough to be heard on the surface of the chest so it was not surprising in this dog that a diastolic heart murmur was not heard. MPA, main pulmonary artery.

©Mark D. Kittleson, D.V.M., Ph.D. All rights reserved.