Interobserver agreement between non-cardiologist veterinarians and a cardiologist after a 6-hour training course for echographic evaluation of basic echocardiographic parameters and caudal vena cava diameter in 15 healthy Beagles

Abstract

Objective: To evaluate cardiovascular focused assessment with sonography for trauma and triage (CV-FAST) interobserver agreement for echocardiographic parameters and caudal vena cava (CVC) diameter measurement, between a cardiologist and 2 non-cardiologists after a 6-hour training course.

Setting: University veterinary teaching hospital.

Animals: Fifteen healthy Beagle dogs.

Interventions: None.

Measurements and main results: Echocardiography parameters were assessed via standardized views. Caudal vena cava was assessed via a subxiphoid window (CVC-SubX) using 3 measurements (minimal and maximal CVC diameter, and collapsibility index) and via a dorsolateral window (CVC-DL) using 1 measurement (CVC diameter). Bland-Altman analysis assessed agreement of each non-cardiologist with the cardiologist; coefficients of variation (CoV) quantified variability between observers. The 95% limits of agreement (LOA) and CoVs were considered acceptable for left atrial diameter, left atrium to aortic ratio, normalized left ventricle diameter in diastole and systole but non-acceptable for fractional shortening and pulmonary vein to pulmonary artery ratio. For CVC-SubX, the 95% LOA for maximum CVC diameter were acceptable, while minimum CVC diameter and CVC collapsibility index were non-acceptable. The CoVs were good for maximum and minimum CVC (7%) and poor for collapsibility index (37%). For CVC-DL, the 95% LOA were non-acceptable, although the CoV was considered good (11%).

Conclusions: A 6-hour training course in echocardiography allows non-cardiologists to assess left atrial diameter, left atrium to aortic ratio, normalized left ventricle diameter in diastole and systole, and CVC_max of the CV-FAST exam in healthy Beagles. Standardization of the CVC-SubX technique and assessment of the impact of the respiratory phase on CVC diameter in dogs is needed. Further studies are required to determine whether interobserver agreement remains acceptable when including different breeds. Assessment of basic echocardiographic parameters and the CVC to estimate volume status in small animal medicine merits further clinical evaluation.

Keywords: FAST; cardiovascular; echocardiography; fractional shortening; volemia.