Table 2.
TBEV equation input and output variables: VC = volume conductor (mL), TSF = systolic flow time (ms), dZ/dtmax = peak time rate of change of the transbrachial impedance pulse variation (Ω s−2, ohm s−2), Z0 = transbrachial quasi-static base impedance (Ω), SV = stroke volume (mL), HR = heart rate (beats min−1), CO = cardiac output (L min−1)
| Pre-MRI session | Males (n = 21) | Females (n = 8) | ||
|---|---|---|---|---|
| Mean ± SD | Range | Mean ± SD | Range | |
| Vc (mL) | 2929 ± 458 | 2144–4000 | 1914 ± 541 | 1571–3286 |
| TSF (ms) | 321 ± 19.2 | 276–356 | 328.8 ± 25.3 | 296–388 |
| dZ/dtmax (Ω s−2) | 0.97 ± 0.39 | 0.47–1.92 | 1.60 ± 0.41 | 1.03–2.46 |
| Z0 (Ω) | 74.3 ± 11 | 49–96 | 86.6 ± 15.4 | 64.9–113.8 |
| SV (mL) | 104.1 ± 16.3 | 75.9–143.8 | 83.8 ± 19.9 | 70.7–135.3 |
| HR (BPM) | 67 ± 8 | 53–86 | 61 ± 7 | 55–71 |
| CO (L min−1) | 6.9 ± 1.1 | 5.1–9.4 | 5.2 ± 1.7 | 3.9–9.7 |
| Post-MRI session | Males (n = 22) | Females (n = 8) | ||
|---|---|---|---|---|
| Mean ± SD | Range | Mean ± SD | Range | |
| Vc (mL) | 2935 ± 448 | 2144–4000 | 1914 ± 541 | 1571–3286 |
| TSF (ms) | 318 ± 22.7 | 278–372 | 328 ± 32.3 | 288–384 |
| dZ/dtmax (Ω s−2) | 0.89 ± 0.29 | 0.42–1.67 | 1.51 ± 0.52 | 0.86–2.65 |
| Z0 (Ω) | 72.1 ± 14.2 | 41.8–100.0 | 90.0 ± 20.7 | 51.4–117.8 |
| SV (mL) | 102.5 ± 18.4 | 55.8–138.2 | 80.0 ± 20.4 | 54.4–128.3 |
| HR (BPM) | 67 ± 8 | 57–86 | 61 ± 7 | 50–72 |
| CO (L min−1) | 6.8 ± 1.3 | 3.4–8.7 | 5.0 ± 1.7 | 3.6–8.9 |