TY - JOUR
T1 - Delayed anaerobic threshold in heart failure patients with atrial fibrillation
AU - Palermo, Pietro
AU - Magrì, Damiano
AU - Sciomer, Susanna
AU - Stefanini, Elisa
AU - Agalbato, Cecilia
AU - Compagnino, Elisa
AU - Chircu, Cristina M.
AU - Maffessanti, Francesco
AU - Teodoru, Minodora
AU - Agostoni, Piergiuseppe
PY - 2016/5/25
Y1 - 2016/5/25
N2 - Purpose: To assess whether atrial fibrillation (AF) in heart failure (HF) affects oxygen uptake at anaerobic threshold (V E O 2 AT) and heart rate (HR) kinetics. METHODS: A total of 15 patients with HF and AF and 18 with HF and sinus rhythm (SR) performed a maximal incremental and 2 constant workload cycle ergometer cardiopulmonary exercise tests (below and above AT, at 25% and 75% of maximal workload, respectively). At constant workload tests, kinetics of VO2 and HR were assessed by calculating time constant (τ).RESULTS: HF patients with AF showed a similar peak VO2 to those with SR (16.7±4.5 mL/kg/min vs 16.6±3.9 mL/kg/min). However, VO2 AT (11.3±2.9 mL/kg/min vs 9.3±2.8 mL/kg/min; P 2 below and above AT were not significantly different.CONCLUSIONS: In HF patients with AF, despite a similar peak VO2 compared with patients with HF and SR, VO2 AT is higher because of a higher HR and a greater HR increase during exercise. One postulated mechanism would be a greater cardiac output increase at the beginning of exercise in HF patients with AF. The delayed AT generates uncertainty about the meaning of a VO2 value at AT in HF patients with AF, because a higher AT is usually associated with better performance and a better prognosis.
AB - Purpose: To assess whether atrial fibrillation (AF) in heart failure (HF) affects oxygen uptake at anaerobic threshold (V E O 2 AT) and heart rate (HR) kinetics. METHODS: A total of 15 patients with HF and AF and 18 with HF and sinus rhythm (SR) performed a maximal incremental and 2 constant workload cycle ergometer cardiopulmonary exercise tests (below and above AT, at 25% and 75% of maximal workload, respectively). At constant workload tests, kinetics of VO2 and HR were assessed by calculating time constant (τ).RESULTS: HF patients with AF showed a similar peak VO2 to those with SR (16.7±4.5 mL/kg/min vs 16.6±3.9 mL/kg/min). However, VO2 AT (11.3±2.9 mL/kg/min vs 9.3±2.8 mL/kg/min; P 2 below and above AT were not significantly different.CONCLUSIONS: In HF patients with AF, despite a similar peak VO2 compared with patients with HF and SR, VO2 AT is higher because of a higher HR and a greater HR increase during exercise. One postulated mechanism would be a greater cardiac output increase at the beginning of exercise in HF patients with AF. The delayed AT generates uncertainty about the meaning of a VO2 value at AT in HF patients with AF, because a higher AT is usually associated with better performance and a better prognosis.
KW - Anaerobic threshold
KW - Atrial fibrillation
KW - Heart rate
KW - Oxygen uptake
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U2 - 10.1097/HCR.0000000000000159
DO - 10.1097/HCR.0000000000000159
M3 - Article
AN - SCOPUS:84969544918
VL - 36
SP - 174
EP - 179
JO - Journal of Cardiopulmonary Rehabilitation and Prevention
JF - Journal of Cardiopulmonary Rehabilitation and Prevention
SN - 1932-7501
IS - 3
ER -