Echocardiographic caudal vena cava measurements in healthy cats and in cats with congestive heart failure and non-cardiac causes of cavitary effusions

Abstract

BackgroundEchocardiographic indices of the inferior vena cava have been associated with elevated right atrial pressures in humans. Hypothesis/objectivesDescribe caudal vena caval (CVC) sonographic dimensions in healthy cats compared to cats with cardiogenic cavitary effusion (CCE), cardiogenic pulmonary edema (CPE), or non-cardiac causes of cavitary effusion (NCE). Animals30 healthy control cats and 52 client-owned cats with CCE, CPE, or NCE examined at two university hospitals. MethodsSagittal 2-dimensional (2D) and M-mode CVC dimensions were acquired from the subxiphoid view. Caudal vena cava collapsibility index (CVC-CI) was calculated. Variables were compared between study groups using Kruskal–Wallis and Dunn's Bonferroni testing. Receiver operating characteristic curves were used to assess sensitivity and specificity for diagnostic categories. ResultsHealthy cats had sagittal 2D and M-mode (median, interquartile range) CVC maximal dimensions of 2.4 mm (1.3–4.0) and 3.4 mm (1.5–4.9) and CVC-CI of 52% (45.2–61.8) and 55% (47.8–61.3), respectively. The CVC maximal dimensions in healthy controls were smaller than in cats with cavitary effusions or pulmonary edema (all P<0.05). CVC-CI was different between CCE and NCE (P<0.0001) with cutoffs of CVC-CI ≤38% (2D) or ≤29% (M-mode) being 90.5% and 85.7% sensitive, and 94.4% and 100% specific for diagnosis of CCE, respectively. Conclusions and clinical importanceCaudal vena cava measurements are larger in cats with cavitary effusions and cats with CPE than healthy cats. In cats with cavitary effusion, decreased CVC-CI, ≤38% (2D) or ≤29% (M-mode), was helpful in distinguishing between cardiogenic and noncardiogenic etiology.