AJP - Heart and Circulatory Physiology, Vol 258, Issue 2 424-H430, Copyright © 1990 by American Physiological Society
Influence of adenosine on left ventricular performance in conscious dogs
G. L. Freeman, J. T. Colston and J. Hultman
Department of Medicine, University of Texas Health Science Center, San Antonio.
Adenosine, a potent vasodilator of both the peripheral and coronary
vasculature, is increasingly used to produce controlled hypotension in the
clinical and experimental setting. To define the influence of adenosine on
left ventricular (LV) performance in conscious closed-chest dogs were
studied six chronically instrumented autonomically blocked animals before
and after the administration of 0.3, 0.6, and 1.2 microM.kg-1.min-1
infusions of adenosine. Systolic performance was quantified by the
end-systolic pressure-volume (Pes-Ves) and stroke work end-diastolic volume
(SW-EDV) relations. Active diastolic performance was quantified by the time
constant of LV relaxation (T), whereas passive diastolic properties were
assessed by comparing LV pressures at a common LV volume. Despite a
decrease of mean arterial pressure of 51 mmHg, adenosine did not change the
slope of the Pes-Ves relation or the end-systolic volume at a pressure of
100 mmHg. The slope of the SW-EDV relation was also unchanged, and its
volume axis intercept was slightly reduced. There were no differences in T
or in the diastolic pressure at a common LV volume. Thus adenosine appears
to have little influence on systolic or diastolic LV performance aside from
its marked affect on afterload, indicating it is a useful agent for
producing controlled hypotension.
