Table 2 Description of heart rate variability data to be analyzed from 24- hour Holter recording
Heart rate variability parameter (Acronym) | Description/Physiological representation |
|---|---|
Low frequency (LF) | Represents contribution of baroreflex activity in overall cardiovascular control |
High frequency (HF) | Represents contribution of cardiac parasympathetic/vagal nervous activity |
Low to high frequency ratio (LF:HF) | Represents the interplay between sympathetic and parasympathetic limbs of the autonomic nervous system |
Standard deviation of the normal | Â |
Wave (SDNN) | Variation (in units of standard deviation) between each successive R-wave in the ECG recording |
Standard deviation of the average | Â |
Normal wave (SDANN) | Average of the variation (in units of standard deviation) between each successive R-wave when comparing multiple 5-minute sections of the ECG recording |
Percentage of normal wave variation (pNN50%) | Percentage of normal R-waves that differ from the wave directly before it by ≥50 milliseconds |