Dynamic vagal control of pacemaker activity in the mammalian sinoatrial node.
Population
Isolated sinus node preparations (rabbit, cat, and sheep)
Design
Preclinical
Authors
Discussion
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Overview
Preclinical vagal entrainment of pacemaker rhythm warrants no practice change; leaves open translation to human rate-control therapies.
Structured PICO
P
Population
Isolated sinus node preparations (rabbit, cat, and sheep)
I
Intervention
Brief (50-150 msec) trains of stimuli applied onto the endocardial surface in the presence of propranolol (3.9 X 10(-6)M) to activate postganglionic vagal terminals
O
Outcome
Electrophysiological changes including hyperpolarization and phasic changes in sinoatrial cycle lengthsurrogate
This preclinical study elucidates the cellular mechanisms by which brief vagal discharges dynamically control sinoatrial periodicity, including paradoxical acceleration of the pacemaker rhythm.
Cite This Study
Jalife et al. (1983) studied this question.