Table 3. Principal components analysis of experimental data using TTX, Flecainide, Nifedipine, and E4031 in Fig 8.
PCA1 is a major axis that underlies overall APD prolongation and explains 52% of the variance. PCA2 mainly detects changes in rise time of the AP upstroke with a smaller contribution of APDtri and explains 25% of the variance.
| PC Axis | APD30 | APD50 | APD80 | APDMXR | APDTri | Rise Time | Stim Delay | Explained Variance Ratio |
|---|---|---|---|---|---|---|---|---|
| 1 | 0.15 | 0.48 | 0.52 | 0.51 | 0.44 | 0.11 | 0.13 | 0.52 |
| 2 | 0.04 | 0.01 | -0.04 | -0.14 | -0.20 | 0.68 | 0.69 | 0.25 |
| 3 | 0.87 | 0.26 | -0.06 | -0.10 | -0.35 | -0.18 | -0.004 | 0.16 |