Heart rate perturbation in chick embryos: a comparison of two methods. Am J Physiol 1991 Jun;260(6 Pt 2):H1864-9
Date
06/11/1991Pubmed ID
2058724DOI
10.1152/ajpheart.1991.260.6.H1864Scopus ID
2-s2.0-0025769166 (requires institutional sign-in at Scopus site) 12 CitationsAbstract
This report compares the effects of two methods of heart rate (HR) perturbation on stroke volume and dorsal aortic flow in the Hamburger-Hamilton stage 24 chick embryo. The sinus venosus was paced at intrinsic HR and at 150, 125, 75, and 50% of intrinsic HR (n = 23). Alternatively, a 1-mm steel probe heated to increase and cooled to decrease HR was applied to the sinus venosus (n = 15). All studies were performed in ovo at 37-38 degrees C. Aortic flow (mm3/S) and stroke volume (mm3/beat) were calculated from aortic velocity, aortic cross-sectional area, and HR. Atrioventricular (AV) inflow velocities were measured during pacing (n = 10) or probe application (n = 11) technique. Dorsal aortic flow was maximum at intrinsic HR and decreased at both increased and decreased HR. Stroke volume decreased proportionally to HR during rate increase. At decreased HR, when AV synchrony was disrupted (pacing), stroke volume was unchanged from intrinsic values. However, when AV synchrony was maintained at decreased HR (cold probe), the embryonic ventricle significantly increased stroke volume.
Author List
Cuneo B, Hughes S, Benson DW JrMESH terms used to index this publication - Major topics in bold
AnimalsBlood Flow Velocity
Chick Embryo
Heart Rate
Hemodynamics
Regional Blood Flow
Stroke Volume