Table 1.
Ca2+ spark parameters in intact Casq2-/- myocytes
| Parameters | Vehicle (n = 87) |
Flecainide (n = 78) |
Tetracaine (n = 84) |
ANOVA P-value |
|---|---|---|---|---|
| Spark Frequency (Sparks·100μm-1·s-1) |
0.84±0.14 | 1.44±0.16#* | 0.48±0.10# | <0.001 |
| Amplitude (ΔF/F0) | 0.89±0.04 | 0.71±0.02#* | 0.89±0.02 | <0.001 |
| FWHM (μm) | 3.35±0.05 | 2.93±0.04#* | 3.13±0.09# | <0.001 |
| FDHM (ms) | 79.5±2.5 | 67.3±1.8#* | 78.5±4.6. | <0.001 |
| Full Width (μm) | 5.52±0.12 | 4.76±0.09#* | 5.31±0.16 | <0.001 |
| Full Duration (ms) | 131±4.0 | 110±3.0#* | 128±5.8 | <0.001 |
| Time to Peak (ms) | 33.9±1.8 | 28.2±1.4 | 32.3±2.9 | 0.053 |
| Maximum Steepness of Upstroke (Δ(F/Fo)/s) | 57.5±2.1 | 53.1±1.7 | 58.8±3.1 | 0.266 |
| Tau (ms) | 91.6±4.9 | 113.0±22.1 | 87.9±6.0 | 0.583 |
| Spark Mass ((ΔF/F0) μm3) | 63.3±8.8 | 31.1±4.0#* | 56.4±12.9 | <0.001 |
All myocytes were bathed for 10 min in experimental solutions containing either vehicle (0.01% ethanol), flecainide (6 μM) or tetracaine (50 μM) prior to recording line-scans. FWHM: spark full width at half maximum amplitude, FDHM: spark duration at half maximum amplitude; data are mean ± S.E.M.; p-values of post-hoc Student's T-test:
#
p < 0.05 vs. vehicle;
*
p < 0.05 flecainide vs. tetracaine; number of sparks analyzed per group: vehicle = 294, flecainide = 461, tetracaine = 155