Heart rate variability
The HRV was measured using a BIOPAC MP150 amplifier with the ECG recording module ECG100C-MRI in R wave at 1000 Hz sampling rate, gain as 1000, LP as 35 Hz and HP as 1 Hz (Biopac Systems Inc., Goleta, CA, USA) and AcqKnowledge 4.3 software. Three Ag/AgCl electrodes with 11-mm diameter (EL503 EKG , Biopac Systems Inc., Goleta, CA, USA) were placed in a Lead II disposition. The beat-to-beat RR intervals were analyzed using the Kubios Premium software (version 3.2) (