The figure is taken from a recent Vet Clinics of North America review article by Lisciandro GR, ©2020 but is also explained well in our 2nd edition of Point-of-care Ultrasound Techniques for the Small Animal Practitioner, ©2021.

The strategy is that if the sonographer feels there is evidence for left-sided congestive heart failure (L-CHF), then do Vet BLUE®.  If Vet BLUE® is “Dry Lung ALL Vet BLUE® Views” there may be left-sided heart disease but there is no evidence for L-CHF.  Conversely, if Vet BLUE® shows “Wet Lung” in a pattern that supports left-sided CHF, then a work-up is urgently needed along with L-CHF therapy.

The strategy is that if the sonographer feels there is evidence for right-sided congestive heart failure (R-CHF), then characterize the caudal vena cava (CVC) and hepatic veins at the AFAST®-TFAST® Diaphragmatico-Hepatic (DH) view.  If the CVC has a “Bounce” or is “flat” (small maximum height), then R-CHF is not present. There may be right-sided heart disease but there is no evidence for right-sided CHF.  Conversely, if the CVC is “FAT” (increased maximum height) especially with distended hepatic veins (“Tree Trunk Sign”), these findings supports (Chou et al. PLOS ONE 2021) right-sided CHF, and a work-up is urgently needed along with R-CHF therapy.

Also, the Global FAST® Non-echo Fallback Views (Lisciandro, Editor, Point-of-care Ultrasound Techniques for the Small Animal Practitioner, ©2014, 2021; Lisciandro, J Vet Emerg Crit Care 2o11) provide important information when echocardiography including TFAST® echocardiography views are not possible because of patient status, i.e., instability, needs forms of restraint.  For example, “Dry Lung ALL Vet BLUE® Views” rules out L-CHF and the TFAST® echocardiography (or complete echocardiography)  can wait until the patient is more stable/tolerant of echocardiography.  More over when there is “Dry Lung” all views, empiric loop diuretic therapy is not indicated for pulmonary edema because no clinically relevant pulmonary edema exists. A “Bounce” or “flat” CVC rules out R-CHF and the FAST® echocardiography (or complete echocardiography)  can wait until the patient is more stable/tolerant of echocardiography.

Our Table for Maximum Heights of the Caudal Vena Cava (CVC) at the AFAST®-TFAST® Diaphragmatico-Hepatic (DH) view help characterize and interpret CVC findings in addition to “Bounce”, “flat”, and “FAT.”

We hope you found this FASTVet Blog helpful.  Please send any comments to Dr. Greg Lisciandro, DVM, DAVP, DACVECC at [email protected]