|
|
||||||||
Cardiovascular and Pulmonary Research Institute, Allegheny University of the Health Sciences, Pittsburgh, Pennsylvania 15212
The goal of this study was to compare
responses to a calcium promoter, BAY y 5959, and dobutamine (Dob) in
heart failure (HF). Dogs
(n = 9) were chronically instrumented
and studied in the conscious state before and after pacing-induced HF.
In the control state, BAY y 5959 (20 µg · kg
1 · min
1)
increased the first derivative of left ventricular (LV) pressure (dP/dt) by 83 ± 8%
and mean arterial pressure (MAP) by 8 ± 2% and decreased heart
rate (HR) by 30 ± 3%. With Dob (10 µg · kg
1 · min
1)
LV dP/dt rose similarly (+80 ± 6%), but HR also rose (+25 ± 4%)
(P < 0.05 vs. BAY y 5959). After HF
developed, BAY y 5959 still increased LV
dP/dt by 108 ± 8% and MAP by 21 ± 2% and decreased HR by 28 ± 4%, whereas Dob increased LV
dP/dt by only 50 ± 7% (P < 0.05 vs. BAY y 5959) and MAP by
7 ± 3%, and HR did not change (+3 ± 3%)
(P < 0.05 vs. BAY y 5959). In HF,
cardiac work increased more (P < 0.05) with BAY y 5959 (+105 ± 13%) compared with Dob (+47 ± 11%), yet myocardial oxygen consumption increased similarly with the
two drugs. Accordingly, mechanical efficiency increased more
(P < 0.05) with BAY y 5959 (+73 ± 14%) than with Dob (+17 ± 12%). These data indicate that
1) increases in contractility mediated directly by Ca2+ are
relatively resistant to desensitization in HF; and
2) the calcium-channel promoter can
produce increases in myocardial contractility and cardiac work similar
to those of Dob at a significantly lower oxygen cost, thereby enhancing
mechanical efficiency in HF.
catecholamine; myocardial contractility; inotropic agents; myocardial oxygen consumption; myocardial efficiency
This article has been cited by other articles:
![]() |
W. Shen, R. M. Gill, J.-P. Zhang, B. D. Jones, A. K. Corbly, and M. I. Steinberg Sodium channel enhancer restores baroreflex sensitivity in conscious dogs with heart failure Am J Physiol Heart Circ Physiol, April 1, 2005; 288(4): H1508 - H1514. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. Nikolaidis, D. Trumble, T. Hentosz, A. Doverspike, R. Huerbin, M. A. Mathier, Y.-T. Shen, and R. P. Shannon Catecholamines restore myocardial contractility in dilated cardiomyopathy at the expense of increased coronary blood flow and myocardial oxygen consumption (MvO2 cost of catecholamines in heart failure) Eur J Heart Fail, June 1, 2004; 6(4): 409 - 419. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Shen, R. M. Gill, B. D. Jones, J.-P. Zhang, A. K. Corbly, and M. I. Steinberg Combined Inotropic and Bradycardic Effects of a Sodium Channel Enhancer in Conscious Dogs with Heart Failure: A Mechanism for Improved Myocardial Efficiency Compared with Dobutamine J. Pharmacol. Exp. Ther., November 1, 2002; 303(2): 673 - 680. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |