Table 1.
Cardiac function, ECG parameters, and heart weight in R6/1 and WT mice at two ages
| 3 months | 7 months | |||
|---|---|---|---|---|
| WT | R6/1 | WT | R6/1 | |
| Haemodynamics | ||||
| HR (bpm) | ND | ND | 363 ± 15 (6) | 399 ± 23 (6) |
| SAP (mmHg) | ND | ND | 100 ± 6 | 85 ± 4 |
| DAP (mmHg) | ND | ND | 72 ± 4 | 57 ± 3* |
| LVSP (mmHg) | ND | ND | 98 ± 6 | 84 ± 3 |
| LVEDP (mmHg) | ND | ND | 5.5 ± 0.2 | 4.5 ± 0.6 |
| dP/dtmax (mmHg s−1) | ND | ND | 6210 ± 710 | 6910 ± 504 |
| dP/dtmin (mmHg s−1) | ND | ND | 6568 ± 730 | 6048 ± 480 |
| Echocardiography | ||||
| HR (bpm) | 525 ± 14 (5) | 431 ± 34 (5)† | 519 ± 10 (9) | 437 ± 21 (9)† |
| LVDd (mm) | 3.98 ± 0.05 | 3.80 ± 0.14 | 4.51 ± 0.15‡ | 3.49 ± 0.12† |
| FS (%) | 33 ± 4 | 33 ± 2 | 27 ± 1 | 28 ± 2 |
| ECG | ||||
| R–R (ms) | 145 ± 3 (5) | 145 ± 3 (5) | 157 ± 4 (6) | 158 ± 10 (5) |
| P–R interval (ms) | 39.2 ± 1.3 | 37.0 ± 0.4 | 38.3 ± 1.1 | 39.2 ± 0.7 |
| QRS interval (ms) | 7.7 ± 0.5 | 8.2 ± 0.7 | 10.4 ± 0.5 | 9.6 ± 0.7 |
| Morphometrics | ||||
| Body weight (g) | 30 ± 1 (14) | 25 ± 1† (8) | 38 ± 2‡ (10) | 22 ± 1† (9) |
| Tibial length (mm) | 17.8 ± 0.2 | 17.7 ± 0.2 | 18.4 ± 0.2‡ | 18.4 ± 0.1‡ |
| Heart (mg) | 126 ± 3 | 108 ± 3† | 140 ± 8‡ | 89 ± 4†‡ |
| Atria (mg) | 10 ± 1 | 10 ± 1 | 12 ± 1 | 7 ± 1†‡ |
| HW/TL (mg mm−1) | 7.1 ± 0.2 | 6.1 ± 0.3† | 7.6 ± 0.4 | 4.8 ± 0.2†‡ |
| Atria/TL (mg mm−1) | 0.57 ± 0.03 | 0.56 ± 0.03 | 0.64 ± 0.03 | 0.37 ± 0.03†‡ |
| HW/BW (mg g−1) | 4.2 ± 0.1 | 4.3 ± 0.1 | 3.7 ± 0.1‡ | 4.1 ± 0.1† |
| Atria/BW (mg g−1) | 0.34 ± 0.02 | 0.40 ± 0.03 | 0.31 ± 0.01 | 0.32 ± 0.03 |
Group size indicated in parentheses. Abbreviations: BW, body weight; DAP, diastolic aortic pressure; dP/dtmax, maximal rate of the rise of left ventricular pressure; dP/dtmin, maximal rate of the fall of left ventricular pressure; FS, fractional shortening; HR, heart rate; HW, heart weight; LVDd, left ventricular dimension at diastole; LVEDP, left ventricular end-diastolic pressure; LVSP, left ventricular systolic pressure; ND, not determined; SAP, systolic aortic pressure; TL, tibial length; WT, wild-type. *P < 0.05 vs. age-matched WT (Student's unpaired t test). †P < 0.05 vs. age-matched WT. ‡P < 0.05 vs. 3-month-old group of same genotype (two-way ANOVA).