Echocardiographic Evaluation of the Right Atrial Area Index in Dogs with Pulmonary Hypertension

Abstract

BackgroundRight atrial area (RAA) is a prognostic factor in human patients with pulmonary arterial hypertension (PAH). Reference intervals for RAA have been described in healthy dogs.ObjectivesTo evaluate RAA indexed to the body surface area in dogs with PAH as an indicator of right atrial size, PAH severity and right‐sided congestive heart failure (R‐CHF).AnimalsA total of 119 client‐owned dogs, 48 dogs with PAH and 71 control dogs.MethodsProspective observational study. Pulmonary arterial hypertension was classified according to the tricuspid regurgitation pressure gradient (TRPG) as mild (36–50 mmHg), moderate (51–75 mmHg), or severe (>75 mmHg). The RAA index was calculated as the RAA divided by body surface area.ResultsThe RAA index was higher in dogs with moderate PAH (13.3 cm2/m2; range, 3.4–24.7 cm2/m2) and severe PAH (12.1 cm2/m2; range, 5.4–21.8 cm2/m2) than in those with mild PAH (6.7 cm2/m2; range, 4.8–10.7 cm2/m2) or in controls (7.3 cm2/m2; range, 4.2–10.2 cm2/m2; P < 0.001). The RAA index was higher (P < 0.0001) in dogs with R‐CHF (17.5 cm2/m2; range, 12.7–24.7 cm2/m2) compared to those without R‐CHF (7.6 cm2/m2; range, 4.4–19.4 cm2/m2). The most accurate cutoff value of the RAA index to identify R‐CHF was >12.3 cm2/m2 (sensitivity, 100%; specificity, 89.5%). In dogs with PAH, severity of tricuspid regurgitation (TR) was the only independent predictor of RAA index based on multivariate analysis (P < 0.02).Conclusions and Clinical ImportanceThe RAA index can be used to evaluate right atrial size in dogs and may be more effective than TRPG in predicting R‐CHF in dogs with PAH. The severity of TR is the main determinant of the RAA index in dogs with PAH.

ACVIM consensus statement guidelines for the diagnosis, classification, treatment, and monitoring of pulmonary hypertension in dogs

“…Recommendations in Tables 2 and 3 for echocardiographic assessment of PH pertain to the use of a probability-based approach for the assessment PH for all causes of PH (groups 1-6, Table 4). In addition to criteria in Tables 2 and 3 Right atrial enlargement 19,20 Underfilling or decreased size of the left ventricle a Peak early diastolic PR velocity >2.5 m/s Enlargement of the caudal vena cava 19 Right ventricular hypertrophy (wall thickening, chamber dilation, or both) 19,21 RPAD index <30% 17,22 Right ventricular systolic dysfunction 19 Given the limitations of the veterinary literature (eg, single case reports or small case series, retrospective study design, frequent presence of confounding comorbid conditions contributing to PH, lack of uniform and rigorous diagnostic testing to definitively rule out comorbid conditions, among others), not all panelists agree with provided references to support the disease as the cause of PH. Larger, prospective carefully designed studies will be required to provide the necessary evidence to further refine this classification scheme.…”

Fatal Pulmonary Hypertension and Right-Sided Congestive Heart Failure in a Kitten Infected with Aelurostrongylus abstrusus

“…Left chamber dimensions, wall thicknesses, and ventricular function were assessed as previously described [20]. Right-heart dimension and function were subjectively and objectively assessed [20,23,24]. The presence of interventricular septal flattening was subjectively assessed.…”

Echocardiographic evaluation of the right ventricular dimension and systolic function in dogs with pulmonary hypertension

“…3D echocardiography is superior to 2D echocardiography to evaluate RV size, however it is time‐consuming, not readily available, and the equipment is expensive. Thus, in clinical practice, 2D evaluation of linear and area dimensions of the RV are the most commonly used variables to assess RV size …”