Atrial trabeculae: Steady-state twitch contractions
| Mechanical parameters | Control | Detubulated | Control | Detubulated | ||
| 1 Hz | 3 Hz | |||||
| Active stress (mN/mm2) | 18.1 ± 5.4 | 18.6 ± 5.7 | NS | 21.3 ± 4.6 | 19.6 ± 3.8 | NS |
| Twitch time to peak (ms) | 71 ± 1 | 73 ± 2 | NS | 72 ± 2 | 72 ± 2 | NS |
| Twitch relaxation time 50% (ms) | 39 ± 6 | 42 ± 4 | NS | 39 ± 6 | 42 ± 4 | NS |
| Twitch relaxation time 90% (ms) | 148 ± 10 | 151 ± 7 | NS | 147 ± 10 | 151 ± 11 | NS |
| Mechanical parameters | Control | Detubulated | Control | Detubulated | ||
| 1 Hz | 3 Hz | |||||
| Active stress (mN/mm2) | 18.1 ± 5.4 | 18.6 ± 5.7 | NS | 21.3 ± 4.6 | 19.6 ± 3.8 | NS |
| Twitch time to peak (ms) | 71 ± 1 | 73 ± 2 | NS | 72 ± 2 | 72 ± 2 | NS |
| Twitch relaxation time 50% (ms) | 39 ± 6 | 42 ± 4 | NS | 39 ± 6 | 42 ± 4 | NS |
| Twitch relaxation time 90% (ms) | 148 ± 10 | 151 ± 7 | NS | 147 ± 10 | 151 ± 11 | NS |
Twitch force before and after formamide shock in atrial trabeculae. The time to 50 and 90% relaxation/decay is measured from the peak of the twitch. NS, not significant in paired Student’s t test. n = 5 and 8, number of rats and number of trabeculae, respectively.