Hemodynamic parameters of stage 20 to stage 35 chick embryo.

Hemodynamic parameters of the chick embryo from stage 20 (3 d of a 21-d incubation) up to stage 35 (8 d) are described. Normal values of dorsal aortic flow velocity wave forms were measured with a 20-MHz directional-pulsed Doppler velocity meter that was validated to be accurate above 5 mm/s. An analysis of variance was carried out for each of the flow velocity parameters. The correlation coefficient that represents the reproducibility was satisfactory (r > 0.90). There was a 17-fold rise in mean dorsal aortic blood flow (mm3/s). Heart rate doubled from 123 +/- 12 to 239 +/- 8 bpm, and stroke volume increased from 0.14 +/- 0.08 to 1.28 +/- 0.55 mm3. A stage-related rise was seen in peak systolic and mean velocities and peak acceleration. These data may serve as a basis for flow velocity wave form investigation and interpretation in developmental stages of cardiac malformations.