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OBJECTIVE This study evaluated cardiac beta-adrenoceptor responsiveness in the elderly. BACKGROUND The hypothesis of reduced cardiac beta-adrenoceptor responsiveness in the elderly is based on a smaller increase in heart rate after administration of isoproterenol, a nonselective beta 1- and beta 2-adrenoceptor agonist. By means of dobutamine-stress-echocardiography we were able to retest the hypothesis more accurately because dobutamine is a relatively selective beta 1-adrenoceptor agonist with weak beta 2- and alpha-adrenoceptor stimulant activity that prevents baroreflex-mediated changes in heart rate. METHODS After administration of stepwise incremental infusions of dobutamine, we measured heart rate and blood pressure responses in 360 patients who had no beta-adrenergic blocking agent therapy and no side effects during the stress test. For each patient we calculated the dose of dobutamine required to increase heart rate by 50% of the maximal heart rate during the highest dose of dobutamine. RESULTS No relation was found between age and sensitivity to dobutamine (n = 293). Power analysis revealed that this negative finding was not the result of inadequate sample size. In contrast to the prevailing hypothesis, an increased heart rate response to dobutamine was found even in a subgroup of "healthy" elderly subjects (i.e., those without concomitant disease or acute myocardial ischemia, n = 67) that was not related to changes in blood pressure during stress. However, in subjects with acute ischemia (n = 109), smokers (n = 151) or patients with a history of a previous myocardial infarction (n = 148), dobutamine sensitivity was reduced in the elderly despite a diminished change in systolic blood pressure with advanced age during dobutamine infusion. This phenomenon could be explained by a decrease in efferent cardiac baroreflex sensitivity, as has been observed during acute myocardial ischemia. There were no age-related differences in plasma concentrations of dobutamine. CONCLUSIONS No evidence for reduced beta-adrenoceptor responsiveness to dobutamine was found in "healthy" elderly subjects.
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
January 1989,
The Journal of clinical endocrinology and metabolism,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
August 1979,
Clinical pharmacology and therapeutics,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
February 2002,
Anesthesiology,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
October 1985,
Chest,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
January 1989,
Archives internationales de pharmacodynamie et de therapie,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
August 1986,
The American journal of physiology,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
June 1984,
Clinical pharmacology and therapeutics,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
January 1996,
Molecular and cellular biochemistry,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
November 1994,
Journal of the American College of Cardiology,
D Poldermans, and
E Boersma, and
P M Fioretti, and
H van Urk, and
F Boomsma, and
A J Man in 't Veld
November 1977,
Naunyn-Schmiedeberg's archives of pharmacology,
