2.4. Analysis of HRV
premature ventricular contraction
PREMATURE VENTRICULAR CONTRACTION, ECTOPIC BEATS
A three-lead electrocardiogram was used for recording of heart rate using a sampling rate of 1000 points per second (LabChart 7 PRO, ADInstruments, Colorado Springs, CO 80906).The methods used for HRV analysis adhere to the standards developed by the Task Force of the European Society of Cardiology the North A Electrophysiology [HRV was assessed by time and frequency domain methods using three 5 min consecutive RR intervals at baseline (BL), after seven days of JD (JD7), and seven days after discontinuation of JD (Post-JD). All ectopic beats resulting from premature ventricular contraction were removed from electrocardiographic waveforms and missing data replaced by interpolated beats derived from the nearest valid data to analyze the normal RR intervals (NN). The variables used for the time domain analysis include the standard deviation of all normal RR intervals (SDNN), standard deviation of the delta of all RR intervals (SD