Table 3.
Predictive power of baroreflex transfer functions
| Open-loop TF (Hn-open, CSP to SNA) | Closed-loop-spontaneous TF (Hn-closed-spon, CSP [= AP] to SNA) | |||
|---|---|---|---|---|
| r2 | (Predicted condition) | r2 | (Predicted condition) | |
| Neural arc | 0.8 ± 0.1* | (Open-loop) | 0.1 ± 0.1 | (Open-loop) |
| 0.1 ± 0.2 | (Closed-loop-spon) | 0.06 ± 0.1 | (Closed-loop-spon) | |
| 0.9 ± 0.1* | (Closed-loop-drug) | 0.7 ± 0.1 (r < 0a) | (Closed-loop-drug) | |
| Open-loop TF (Hp-open, SNA to AP) | Closed -loop-spontaneous TF (Hp-closed-spon, SNA to AP) | |||
|---|---|---|---|---|
| r2 | (Predicted condition) | r2 | (Predicted condition) | |
| Peripheral arc | 0.8 ± 0.1* | (Open-loop) | 0.7 ± 0.1* | (Open-loop) |
| 0.7 ± 0.1* | (Closed-loop-spon) | 0.7 ± 0.1* | (Closed-loop-spon) | |
Values are mean ± SD (n = 10).
*
P < 0.05; significant correlation between predicted and measured values.
a
Regarding the predictive power of closed-loop-spontaneous TF in neural arc closed-loop-drug condition, r is less than 0 (r =−0.8 ± 0.1). TF, transfer function; Open-loop, baroreflex open-loop condition where CSP was binary random (white-noise) sequence and independent of systemic AP; Closed-loop-spon, baroreflex closed-loop-spontaneous condition where CSP equalled systemic AP; Closed-loop-drug, sequential infusions of phenylephrine and nitroprusside in closed-loop condition where CSP equalled systemic AP.