Purpose: Exaggerated sympathetic nervous system (SNS) activity associated with low heart rate variability (HRV) is considered as a trigger of cardiac arrhythmias and sudden death. Regular exercise training is efficient to improve autonomic balance. In 2013, the investigators published that a single session of an optimized short-high intensity interval exercise with passive recovery (HIIT) protocol was efficient in chronic heart failure (CHF) patients for enhancing vagal tone and to decrease arrhythmias in the 24-h post exercise period when compared to a single session of moderate intensity continuous exercise (MICT). Nevertheless the effects of HIIT training performed on several weeks have never yet been studied on the parameters described by Coumel's triangle (the arrhythmogenic substrate, the trigger factor as premature ventricular contraction and the modulation factors of which the most common is the autonomic nervous system). The aim of this study was to verify the superiority of HIIT to enhance parasympathetic activity, cardiorespiratory fitness and cardiac function when compared to MICT in a short and intense cardiac rehabilitation program.
Before and after the Rehabilitation Program (RP), all patients underwent a 24-hour ECG recording, an echocardiography, a cardiopulmonary exercise test. The RP consisted of 2 types of exercise training according to the randomization: 1. a short-high intensity interval exercise with passive recovery 2. a classical moderate and continuous exercise training at 60% of peak power output The RP lasted 4 weeks.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
DOUBLE
Enrollment
32
to compare MICT vs HIIT 5 days/week during 4 weeks in a Cardiovascular Centre.
High Frequency power in normalized units (HFnu%)
based on Heart Rate Variability, the power spectral density of the HF (0.15-0.40 Hz, ms2.Hz-1) bands were calculated.
Time frame: Change from baseline through study completion, an average of 4 weeks (measured during the night period for stationary signal)
maximal oxygen consumption (VO2peak ml.min.kg)
VO2 at peak exercise was measured with Cardiopulmonary Exercise Test.
Time frame: Change from baseline through study completion, an average of 4 weeks
First ventilatory threshold (VT1) (ml.min.kg)
VO2 at VT1 was measured with Cardiopulmonary Exercise Test.
Time frame: Change from baseline through study completion, an average of 4 weeks
Heart Rate Recovery (beats per minute, bpm)
Heart Rate Recovery (with passive recovery) at 1, 2 and 3 minutes after peak exercise (in beats per minute, bpm)
Time frame: Change from baseline through study completion, an average of 4 weeks
Left Ventricular Ejection Fraction (LVEF, %)
LV volumes and ejection fraction were calculated from apical recordings by modified biplane Simpson's method.
Time frame: Change from baseline through study completion, an average of 4 weeks
premature ventricular contraction, (n/24h)
Ectopic ventricular beats were classified as isolated premature contractions, bigeminy, and salves.
Time frame: Change from baseline through study completion, an average of 4 weeks
NT-pro-BNP, (ng/L)
blood sample analysis
Time frame: Change from baseline through study completion, an average of 4 weeks
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