This is a prospective study to evaluate changes in exercise capacity and chronotropic response to exercise before and after beta-blocker dosage reduction in patients with atrial fibrillation (AF).
Rate control therapy is the first-line treatment for atrial fibrillation (AF). Resting heart rate(HR) is the treatment target of rate control therapy in current clinical practice; However, the optimal value for resting heart rate in AF remained unclear. Beta-blocker(BB) is widely used as rate-control agent. It is concerned that excessive use of BB might lead to a negative effect on exercise capacity in patients with AF. The aim of this study is to explore the effect of Beta-blocker on hemodynamic parameters and peak oxygen uptake during cardiopulmonary exercise test (CPET).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
40
Phase I: 1. CPET performed at trough BB concentration: participants will undergo CPET at least 30 hours after last beta-blocker usage. 2. CPET performed at peak BB concentration : participants will undergo CPET at 3 hours after last beta-blocker usage. Phase II: BB dosage will be reduced.
National Taiwan University Hospital
Taipei, Taiwan
RECRUITINGPeak oxygen intake
Peak oxygen intake will be assessed with symptom-limited cardiopulmonary exercise testing.
Time frame: The change in peak oxygen uptake will be measured at day 0 , day 7 and day 21.
Chronotropic response to exercise
Plasma norepinephrine level was obtained before and immediately after cardiopulmonary exercise testing to assess the relationship of beta-blocker, circulating norepinephrine level and chronotropic response to exercise.
Time frame: The change in chronotropic response to exercise will be measured at day 0 , day 7 and day 21.
European Heart Rhythm Association (EHRA) symptom scale
The investigators will assess the change in EHRA symptom scale. The EHRA score ranges from 1 to 4. Higher scores indicate more severe symptoms.
Time frame: The change in European Heart Rhythm Association (EHRA) score will be measured at day 0 , day 7 and day 21.
Cardiac output and stroke volume
Cardiac output and stroke volume during incremental exercise testing will be assessed by impedance cardiography.
Time frame: The change in cardiac output and stroke volume will be measured at day 0 , day 7 and day 21.
Cognitive function
The investigators will assess the change in Montreal Cognitive Assessment (MoCA). The total score of MoCA ranges from 0 to 30. Higher scores indicate better cognitive function.
Time frame: The change in MoCA will be measured at day 0 , day 7 and day 21.
NT-proBNP
NT-proBNP level will be assessed before and immediate after the cardiopulmonary exercise test.
Time frame: The change in NT-proBNP will be measured at day 0 , day 7 and day 21.
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Quality of life evaluation
The investigators will assess the change in 36-Item Short Form Survey (SF-36). SF-36 consists of eight domains of health status. The score of each domain ranges from 0 to 100. Higher scores indicate a better outcome.
Time frame: The change in SF-36 will be measured at day 0 , day 7 and day 21.