Echocardiographic reference intervals for right ventricular indices, including 3-dimensional volume and 2-dimensional strain measurements in healthy dogs

Figures

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  FIGURE 1. Illustration of strain measurement using STE. (A) Definition of the endocardial borders of the RV. (B) The software generates Strain curves of all 6 segments. Strain values are given as peak (PK), end‐systolic (ES), and time to peak (TTP). RV, right ventricle; STE, speckle‐tracking echocardiography

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  FIGURE 2. (A) Identification of anatomic landmarks in end‐diastole in the left‐apical 4‐chamber view. Markers were placed as shown at the LV apex and in the center of the mitral valve as well as at the RV apex and in the center of the tricuspid valve. Followed by the landmarks of the short axis, aortic valve leaflets in the LV outflow tract were determined as well as the RV in short‐axis. (B) Automatically tracing of the endocardial borders by the software in long‐axis as well as in short axis at basal, medial, and apical levels in end‐systole and end‐diastole followed by manual adjustment if necessary. A 3D dynamic RV model including complete RV volume determination with EDV, ESV, SV, and EF is generate. EDV, end‐diastolic volume; EF, ejection fraction; ESV, end‐systolic volume; LV, left ventricle; RV, right ventricle; SV, stroke volume

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  FIGURE 3. Comparison of the linear regression (blue lines) and the additive model (black lines) for each RV function index. Upper and lower prediction intervals and the means are displayed as dashed and solid lines, respectively. RV, right ventricle

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  FIGURE 4. Scatter Plots and regression line (middle line) of the normalized RV indices using the calculated exponents. 95% prediction intervals are displayed (upper and lower lines). (A) End‐diastolic volume normalized (EDVn); (B) End‐systolic volume normalized (ESVn); (C) End‐diastolic area normalized (EDAn); (D) End‐systolic area normalized (ESAn); (E) Peak systolic tissue velocity normalized (TVI S′n); (F) Tricuspid annular plane systolic excursion normalized (TAPSEn). RV, right ventricle