Table 2.
Histomorphometric analysis of right and left ventricular myocardium of hearts from lambs with right ventricular overload and from control lambs
| RV | LV | |||||
|---|---|---|---|---|---|---|
| Control | RV overload | P (*) | Control | RV overload | P (*) | |
| Endocardial volumes (%) | ||||||
| Myocytes | 77.3±6.1 | 72.2±7.1 | 0.26 | 81.3±6.8 | 77.9±9.4 | 0.54 |
| Myocyte nuclei | 2.0±0.4 | 2.1±0.5 | 0.77 | 1.6±0.3 | 2.3±0.7 | 0.06 |
| Collagen | 6.4±1.4 | 7.8±5.5 | 0.87 | 4.2±1.8 | 6.4±1.5 | 0.57 |
| Tissue gap | 13.9±3.2 | 14.6±8.7 | 0.60 | 8.2±4.6 | 10.3±6.8 | 0.07 |
| Rest | 2.4±4.1 | 5.4±3.6 | 0.25 | 6.4±3.3 | 5.4±2.9 | 0.63 |
| Mid-myocardial volumes (%) | ||||||
| Myocytes | 81.0±3.2 | 78.4±7.9 | 0.51 | 86.0±3.9 | 83.5±10.9 | 0.64 |
| Myocyte nuclei | 2.1±0.9 | 2.0±0.3 | 0.80 | 1.7±0.2 | 2.4±0.4 | <0.05 |
| Collagen | 7.4±1.5 | 8.2±5.3 | 0.75 | 4.5±1.8 | 5.3±2.3 | 0.46 |
| Tissue gap | 7.4±4.2 | 8.1±2.0 | 0.75 | 5.7±2.5 | 8.2±6.6 | 0.59 |
| Rest | 4.2±4.0 | 5.3±6.1 | 0.74 | 3.7±2.1 | 3.0±4.1 | 0.74 |
| Epicardial volumes (%) | ||||||
| Myocytes | 73.3±8.6 | 68.8±10.8 | 0.48 | 82.3±5.9 | 75.9±8.7 | 0.21 |
| Myocyte nuclei | 1.9±0.3 | 1.7±0.2 | 0.20 | 1.7±0.3 | 2.3±0.6 | 0.05 |
| Collagen | 12.3±2.8 | 14.5±5.7 | 0.70 | 6.7±2.4 | 8.3±4.9 | 0.38 |
| Tissue gap | 9.9±5.1 | 11.3±5.7 | 0.45 | 6.5±2.1 | 8.5±4.3 | 0.53 |
| Rest | 4.5±4.4 | 5.5±4.7 | 0.74 | 4.6±3.4 | 7.4±3.3 | 0.23 |
The relative volume fractions of myocytes, myocyte nuclei, amount of collagen and tissue gaps in the LV and RV of the control group (left column) and RV pressure overload group (right column) are given. ‘Rest’ represents all structures other than those mentioned above (e.g. vasculature and fibroblasts). A distinction between epicardial, mid-myocardial and endocardial layers was based on different myocyte fiber orientation.
*
Unpaired Student's t-test: RV overload vs. control. Bold type indicates a significant difference.