Template:Windle1940 table4
From Embryology
| Age | Length of heart (mm) | Heart rate (/min) | P-R interval (sec) | Duration of R rise (sec) | Duration of R-T complex (sec) | Approximate conduction speed (mm/sec) |
|---|---|---|---|---|---|---|
| 40 hr. embryo | 0.8 | 120 | none | .009-.012 | 0.28-0.82 | 2.67 |
| 60 hr. embryo | 1.2 | 163 | 0.11 | .008-.010 | 0.20-0.21 | 3.80 |
| 120 hr. embryo | 2.0 | 230 | 0.09 | .010 | 0.21-0.24 | 6.85 |
| 5 day chick | 14.0 | 295 | 0.06 | .004-.006 | 0.24-0.33 | 40.58 |
| Adult hen | 40.0 | 320 | 0.06 | .009 | 0.15-0.18 | 117.77 |
