Table 1.
Changes in indexes of LV afterload and preload and in a calculated index of cardiac output with vagal stimulation (VS) on and off
| VS | Baseline | Dobutamine 5 μg kg min−1 | Dobutamine 10 μg kg min−1 | Dobutamine 15 μg kg min−1 | Re-baseline | Dobutamine 15+Atropine | |
|---|---|---|---|---|---|---|---|
| Mean arterial pressure (mmHg) | OFF | 95.5 ± 4.0 | 96.9 ± 4.1 | 104.6 ± 3.3 | 101.9 ± 2.6 | 101.3 ± 2.6 | |
| ON | 92.0 ± 4.8 | 94.4 ± 3.8 | 96.1 ± 3.6 | 92.2 ± 3.4 | 96.6 ± 2.9 | ||
| Ea (mmHg ml−1) | OFF | 34.20 ± 4.55 | 30.68 ± 2.00 | 28.55 ± 3.47 | 23.36 ± 2.08 | 38.13 ± 4.01 | |
| ON | 40.96 ± 4.69 | 34.38 ± 3.11 | 32.64 ± 3.05 | 32.45 ± 4.31** | 24.47 ± 3.08** | ||
| End-diastolic diameter (mm) | OFF | 42.62 ± 0.73 | 42.33 ± 0.73 | 42.89 ± 0.91 | 43.75 ± 1.01 | 42.57 ± 0.87 | |
| ON | 42.30 ± 0.88 | 41.84 ± 0.83 | 41.78 ± 0.86 | 41.63 ± 0.88 | 41.58 ± 1.01 | ||
| (EDD – ESD) × HR (mm min−1) | OFF | 451.45 ± 47.91 | 576.43 ± 61.22 | 766.20 ± 60.43 | 794.40 ± 52.35 | 491.08 ± 36.35 | |
| ON | 390.14 ± 43.71 | 426.32 ± 28.34 | 467.78 ± 36.65**# | 491.94 ± 43.91**# | 692.73 ± 93.65** |
Heart rate was fixed at 165 beats min−1. Ea, arterial elastance; EDD, end-diastolic diameter; ESD, LV end-systolic diameter. Values are mean ± SEM, n= 11. **P < 0.05 vs. VS baseline; #P < 0.05 vs. corresponding time point pre-VS.