Impaired chronotropic response to exercise in patients with congestive heart failure. Role of postsynaptic beta-adrenergic desensitization.
Why the study?
What is the mechanism responsible for the attenuated heart rate response to exercise in patients with congestive heart failure?
Population
105 subjects, comprising 46 normal subjects and 59 patients with congestive heart failure stratified by peak…
Comparison
Exercise testing, graded isoproterenol infusion… vs Normal subjects.
Design
Cross-sectional
Authors
Discussion
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Member takes
Implication
Blunted chronotropic response may limit exercise capacity in CHF; leaves open whether beta-adrenergic desensitization is causal.
Structured PICO
What is the mechanism responsible for the attenuated heart rate response to exercise in patients with congestive heart failure?
P
Population
105 subjects, comprising 46 normal subjects and 59 patients with congestive heart failure (CHF) stratified by peak exercise oxygen consumption (VO2).
I
Intervention
Exercise testing, graded isoproterenol infusion, and milrinone infusion (in CHF patients).
C
Comparator
Normal subjects.
O
Outcome
Heart rate (HR) response to exercise, peak exercise norepinephrine (NE) level, and the ratio of exercise increments in HR and NE.surrogate
Cite This Study
Colucci et al. (1989) studied this question.