Table 1.
Phenotypic characteristics of 24-week-old mutant and control mice.
| Echocardiography | ContM | MyHC | P value | ContT | TnT | P value |
|---|---|---|---|---|---|---|
| Body weight (g) | 28.1 ± 0.8 | 28.6 ± 1.5 | 0.5 | 27.1 ± 1.3 | 29.4 ± 2.6 | 0.5 |
| Heart Rate (bpm) | 517 ± 25 | 523 ± 22 | 0.4 | 521 ± 22 | 505 ± 30 | 0.08 |
| LVESD (mm) | 2.6 ± 0.2 | 2.9 ± 0.3 | 0.02 | 2.4 ± 0.4 | 2.1 ± 0.3 | 0.03 |
| LVEDD (mm) | 3.9 ± 0.2 | 4.1 ± 0.3 | 0.1 | 3.8 ± 0.4 | 3.5 ± 0.3 | 0.02 |
| LVEF (%) | 63 ± 5 | 57 ± 8 | 0.01 | 67 ± 7 | 71 ± 8 | 0.2 |
| LVFS (%) | 34 ± 4 | 29 ± 5 | 0.02 | 37 ± 5 | 39 ± 6 | 0.1 |
| Stroke volume (µl) | 43 ± 7 | 43 ± 7 | 0.8 | 44 ± 10 | 37 ± 7 | 0.03 |
| LV mass (mg) | 123 ± 14 | 139 ± 22 | 0.03 | 124 ± 29 | 108 ± 15 | 0.04 |
| Gross anatomy and histology | ||||||
| Heart weight (g) | 0.13 ± 0.01 | 0.15 ± 0.01 | 0.03 | 0.12 ± 0.01 | 0.10 ± 0.05 | 0.03 |
| HW/tibial length | 0.070 ± 0.004 | 0.081 ± 0.006 | 0.03 | 0.065 ± 0.003 | 0.059 ± 0.003 | 0.006 |
| Picrosirius red staining (%) | 0.59 ± 0.00 | 1.94 ± 0.01 | 0.007 | 0.55 ± 0.00 | 1.82 ± 0.00 | < 0.001 |
LV; left ventricular, LVESD; LV end systolic diameter, LVEDD; LV end diastolic diameter, LVEF; LV ejection fraction, LVFS; LV fractional shortening, HW; heart weight.
Two-sided unpaired student’s t-test was used for statistical comparisons between mutants and littermate controls (ContM vs MyHC and ContT vs TnT). For ECHO data, ContM (n = 15), MyHC (n = 20), ContT (n = 20), TnT (n = 18) were studied. For gross anatomy, n = 4 mouse hearts were included in each group. For histology, 20 randomly selected fields in the septum, apex and lateral wall were examined in each mouse heart (n = 2 mouse hearts in each group).