Table 1. M-mode and two-dimensional echocardiographic reference intervals obtained in a population of 57 healthy adult American Staffordshire Terriers.
| Variable | Median | Lower RI | (90% CI) | Upper RI | (90% CI) |
|---|---|---|---|---|---|
| M-mode | |||||
| IVSd (mm) | 10.7 | 5.9 | 5.4–7.0 | 14.3 | 13.6–14.3 |
| LVIDd (mm) | 43.0 | 34.4 | 34.0–37.0 | 51.2 | 48.8–52.4 |
| LVFWd (mm) | 9.1 | 6.2 | 5.9–6.9 | 12.1 | 11.3–12.2 |
| IVSs (mm) | 14.0 | 8.1 | 6.6–10.8 | 21.6 | 19.8–22.0 |
| LVIDs (mm) | 27.6 | 17.6 | 16.0–28.8 | 36.9 | 33.7–38.4 |
| LVFWs (mm) | 14.0 | 9.3 | 8.9–11.0 | 19.1 | 16.9–19.6 |
| FS (%) | 34.3 | 20.1 | 18.4–27.8 | 56.4 | 47.9–56.4 |
| LVIDDn | 1.64 | 1.27 | 1.27–1.42 | 1.87 | 1.79–1.90 |
| LVIDSn | 0.99 | 0.64 | 0.60–0.73 | 1.31 | 1.21–1.38 |
| 2D | |||||
| Ao (mm) | 18.6 | 13.9 | 12.5–15.2 | 23.7 | 22.3–25.1 |
| wAo | 0.78 | 0.61 | 0.55–0.65 | 0.97 | 0.92–1.02 |
| PA (mm) | 18.2 | 14.0 | 12.7–15.4 | 23.3 | 21.9–24.6 |
| Ao/PA | 1.02 | 0.80 | 0.73–0.85 | 1.26 | 1.19–1.32 |
| LA/Ao | 1.39 | 1.00 | 1.00–1.04 | 1.75 | 1.66–1.75 |
| SI | 1.41 | 1.15 | 1.15–1.23 | 2.10 | 1.75–2.10 |
| EF (%) | 60.7 | 40.5 | 35.3–46.0 | 82.5 | 76.5–88.0 |
| EDVI (ml/m2) | 59.4 | 37.1 | 33.8–41.4 | 86.7 | 79.3–92.8 |
| ESVI (ml/m2) | 21.9 | 9.5 | 6.3–13.0 | 35.3 | 31.4–38.4 |
RI, reference interval; CI, confidence interval; IVS, interventricular septal thickness; LVID, left ventricular internal diameter; LVFW, left ventricular free wall thickness; d, diastole; s, systole; FS, fractional shortening; LVIDDn, left ventricular internal diameter in diastole normalized for body weight; LVIDSn, left ventricular internal diameter in systole normalized for body weight; Ao, aortic annulus; wAo, index of aortic root dimension; PA, pulmonic annulus; LA/Ao, left atrial-to-aortic ratio; SI, sphericity index; EF, ejection fraction; EDVI, end-diastolic volume index; ESVI, end-systolic volume index.