Case Studies In Small Animal

Cardiovascular Medicine

Home Up Radiographs ECG 2D Echoes Color Flow Doppler Angiogram Diagnosis

Case 39

Pulsed wave Doppler

This image shows flow velocity across the tricuspid valve in diastole. Note that during mid- and late diastole the flow velocity is almost perfectly steady at around 1.5 m/s. Then during atrial systole the velocity increases remarkably as the right atrium contracts to push more blood into the right ventricle. When this occurs, the velocity shoots upward to around 3 m/s. This means that during late diastole, the right atrial pressure is around 36 mmHg (3 squared times 4; modified Bernoulli equation) higher in the right atrium than it is in the right ventricle. Normal right atrial pressure is 5 mmHg or less. This should be seen as jugular vein pulsation on physical exam but wasn't in Sarah's case because of the subcutaneous edema she had in her neck.



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