Table 2 Coefficients and statistical significance of the quadratic term in equations regressing heart rate variability indices on lag.
From: Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure
HRV index | CHF patients | Normal subjects | ||
|---|---|---|---|---|
Coefficient | P | Coefficient | P | |
Beat sequence length = 50 | ||||
SDLD | 0.00002 | 0.769 | -0.00033 | 3.5 × 10-5 |
SD1 | 0.00002 | 0.741 | -0.00020 | 3 × 10-5 |
SD2 | -0.00004 | 0.417 | 0.00010 | 0.002 |
SD1/SD2 | 0.00062 | 0.553 | -0.00510 | 0.0003 |
Beat sequence length = 50000 | ||||
SDLD | 1.5 × 10-6 | 0.968 | -0.00028 | 1 × 10-7 |
SD1 | 2.27 × 10-6 | 0.932 | -0.00020 | 1.4 × 10-7 |
SD2 | -0.00001 | 0.502 | 0.00003 | 0.078 |
SD1/SD2 | 0.00028 | 0.531 | -0.00158 | 4 × 10-8 |