83978
document
Short-term effects of denopamine on anaerobic threshold and related parameters in patients with chronic heart failure : a double-blind crossover study . BACKGROUND The short-term effects of denopamine , an orally available beta-stimulant , on exercise capacity were studied in patients with chronic heart failure . METHODS AND RESULTS Nineteen patients entered the study . Three patients had ischemic heart disease , 13 had dilated cardiomyopathy , and three had valvular disease ; 16 patients were in New York Heart Association class II , and three patients were in New York Heart Association class III . Symptom-limited exercise testing ( ramp protocol ) on a bicycle ergometer with gas exchange analysis was conducted 1 hour after oral administration of either 20 mg denopamine or placebo . Drug administration sequence was randomly assigned in a double-blind crossover method , with 1 week between drugs . Peak VO2 was 20.4 +/- 3.2 and 21.2 +/- 3.1 ml/min/kg , respectively , for those administered the placebo and the drug , and anaerobic threshold was 13.1 +/- 2.1 and 14.0 +/- 2.0 ml/min/kg . There was a significant increase in peak VO2 ( p < 0.05 ) and anaerobic threshold ( p < 0.01 ) with denopamine , whereas no significant change was observed in peak work rate or exercise time . Denopamine increased heart rate in patients with atrial fibrillation but had little effect on heart rate in patients with sinus rhythm . CONCLUSION Data obtained from gas exchange analysis are more sensitive and potentially more useful in the detection of short-term changes in exercise capacity than data obtained from either exercise time or peak work rate , indexes that are commonly used to assess drug therapy . Patients with mild-to-moderate heart failure with sinus rhythm , but not those with atrial fibrillation because of its frequent induction of tachycardia , may be good candidates for denopamine therapy .
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Intervention_Pharmacological
denopamine
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Intervention_Pharmacological
denopamine
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Intervention_Physical
ergometer
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Intervention_Pharmacological
20 mg denopamine
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Intervention_Control
placebo
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Intervention_Control
placebo
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Intervention_Pharmacological
denopamine
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Intervention_Pharmacological
Denopamine
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Intervention_Pharmacological
denopamine
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Outcome_Physical
anaerobic threshold and related parameters
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Outcome_Physical
Peak VO2
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Outcome_Physical
anaerobic threshold
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Outcome_Physical
peak work rate or exercise time .
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Outcome_Physical
heart rate
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Outcome_Physical
heart rate
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Outcome_Physical
exercise capacity
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Participant_Condition
chronic heart failure
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Participant_Sample-size
Nineteen
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Participant_Sample-size
Three
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Participant_Condition
ischemic heart disease
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Participant_Condition
dilated cardiomyopathy
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Participant_Condition
valvular disease ;
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Participant_Condition
atrial fibrillation
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Participant_Condition
sinus rhythm
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Participant_Condition
mild-to-moderate heart failure
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Participant_Condition
sinus rhythm
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Participant_Condition
atrial fibrillation
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Participant_Condition
tachycardia