Partitioning total heart rate variability.

Abstract This study investigates the structure of total heart rate variability (HRV) by partitioning the variance of RR intervals into normalized short-( CS ) and long-term ( CL ) contributions, and CS into contributions derived from heart rate accelerations ( CS a ) and decelerations ( CS d ). Total HRV ( SDNN ) and its partitions were quantified in resting 30-minute ECG recordings from 160 young healthy volunteers (18–30 years old; 75 females). CS (13.4+/–6.4%) was lower than CL (86.6+/–6.5%) in all subjects ( p −15 ) while CS d (7.3+/–3.8%) was higher than CS a (6.1+/–2.9%) in 124 participants ( p −12 ). CS , CL , CS d and CS a have significantly different contributions to total HRV.