Table 1.
Summary of sarcomere measurements as a function of exclusion criteria for the intact heart, cardiac slice, and single cell preparations in cardioplegic conditions
| Preparation | Exclusion Criteria | N | Mean ± SD, μm | Mode ± SD, μm | Lmin, μm | Bounds, μm | |
|---|---|---|---|---|---|---|---|
| Intact heart | None (all SLM <5 min) | 300 | 2.05 ± 0.18 | 1.95 ± 0.02 | |||
| +Angle ±30° from x-axis | 218 | 1.98 ± 0.12 | 1.95 ± 0.02 | ||||
| +Lmin | 162 | 1.99 ± 0.12 | 1.95 ± 0.02 | 72 | 1.90–1.97 | ||
| Cardiac slice | None (all SLM included) | 80 | 1.80 ± 0.13 | 1.78 ± 0.03 | |||
| +Lmin | 72 | 1.81 ± 0.13 | 1.79 ± 0.03 | 39 | 1.71–1.82 | ||
| Cells | None (all SL) | 313 | 1.71 ± 0.10 | 1.71 ± 0.02 |
The bandwidth for the kernel density estimations is set to 0.06 μm for all mode calculations to allow comparisons between mode values based on the highest bandwidth values calculated for whole heart and slice preparations. The minimum path length, Lmin, is calculated based on n values using Eq. S2 in the Online Supplement for preparations where the angle of the cell relative to the imaging plane is uncertain. SLM, measured sarcomere length (SL); N, no. of hearts.