ISSN:
1432-2013
Schlagwort(e):
Neonatal Heart
;
Vagal Stimulation
;
Sino-Auricular Node
;
Heart Interval
;
Neonatales Herz
;
Vagusreizung
;
Sinusknoten
;
Herz-Intervall
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary In two groups of young rabbits, aged 0–5 and 9–23 days, the effect on the heart interval of stimulation of the right and left vagal nerves separately was investigated at frequencies of 1, 2, 4, 8 and 16 stimuli per second. Up to and including 8 stimuli per second, this is well described by log10 (I f /I o )=Hf, orI f =I o L f =I o e hf , whereI o andI f are the heart intervals before and during stimulation respectively at frequencyf, L is a lengthening factor,H=log10 L andh=2.3026 H. Thus each increase in vagal stimulation multiplies the heart interval by a constant factor. the response as defined by H were estimated for both right and left vagal nerves in 15 rabbits, and right or left only in 7 others. The responses varied considerably in individual rabbits and were much larger for almost all in the younger group. The effects of right compared with left stimulation, and of deviations of observed from fitted interval ratios, are studied in detail. Some other mathematical forms given in the literature for the response curves are discussed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00587492
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