Table 4.
Transfer function analysis (TFA) of mean arterial pressure (MAP) and mean cerebral blood flow velocity (CBFV) in ventricular assist device (VAD) cases and controls
| VAD | VLF | LF | HF | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Coh | Gain | Phase | Coh | Gain | Phase | Coh | Gain | Phase | |
| VAD1 | 0.67 | 1.35 | 1.00 | 0.65 | 1.20 | -0.38 | 0.67 | 0.75 | 0.51 |
| VAD2 | 0.76 | 1.82 | 0.98 | 0.79 | 1.25 | -0.08 | 0.68 | 1.96 | 0.30 |
| VAD3 | 0.20 | 0.95 | 0.32 | 0.45 | 1.52 | 0.27 | 0.54 | 1.13 | 0.21 |
| VAD4 | 0.44 | 0.89 | 0.90 | 0.82 | 0.83 | 0.51 | 0.74 | 0.79 | 0.16 |
| VAD5 | 0.45 | 0.63 | 1.04 | 0.56 | 1.18 | 0.72 | 0.77 | 0.72 | 0.00 |
| Mean ± SD | 0.50 ± 0.22 | 1.13 ± 0.47 | 0.85 ± 0.30 | 0.65 ± 0.16 | 1.20 ± 0.25 | 0.21 ± 0.44 | 0.68 ± 0.09 | 1.07 ± 0.52 | 0.24 ± 0.19 |
| Control | VLF | LF | HF | ||||||
| Coh | Gain | Phase | Coh | Gain | Phase | Coh | Gain | Phase | |
| C1 | 0.13 | 0.55 | 0.73 | 0.65 | 0.65 | 0.62 | 0.74 | 0.36 | -0.09 |
| C2 | 0.61 | 1.43 | 0.63 | 0.21 | 1.71 | -0.24 | 0.32 | 2.29 | 0.27 |
| C3 | 0.72 | 1.33 | 0.33 | 0.30 | 1.89 | 0.07 | 0.34 | 2.24 | -0.15 |
| C4 | 0.46 | 1.12 | -0.27 | 0.25 | 1.07 | -0.40 | 0.28 | 1.02 | -0.18 |
| C5 | 0.25 | 1.15 | -1.71 | 0.51 | 1.18 | 0.76 | 0.91 | 1.28 | 0.21 |
| Mean ± SD | 0.43 ± 0.25 | 1.12 ± 0.34 | -0.06 ± 1.00 | 0.38 ± 0.19 | 1.30 ± 0.50 | 0.16 ± 0.51 | 0.52 ± 0.29 | 1.44 ± 0.83 | 0.01 ± 0.21 |
| P | 0.65 | 0.96 | 0.089 | 0.039* | 0.69 | 0.88 | 0.26 | 0.42 | 0.11 |
VLF, very low frequency (0.02-0.07 Hz); LF, low frequency (0.07-0.2 Hz); HF, high frequency (0.2-0.35 Hz). Coh, gain (in cm/s/mmHg) and phase (in rad) are the transfer function coherence, gain and phase from MAP to mean CBFV.
*P < 0.05 from t-test between VAD and Control.