Reproducibility of heart rate variability from short-term recordings during five manoeuvres in normal subjects

PRIMARY OBJECTIVE: Due to limited and contradictory information available, the reproducibility of temporal and spectral measurements of heart rate variability from short-term recordings was evaluated in normal subjects during supine, controlled breathing, standing, exercise and recovery conditions. METHODS AND PROCEDURES: Five-minute tachograms from 11 individuals were obtained during the specified manoeuvres, and repeated three times in a five day period. Besides temporal and spectral indexes, the central frequencies were also computed. MAIN OUTCOMES AND RESULTS: The ANOVA presented non-significant differences among the repetitions for any of the parameters studied. Most intra-class correlation coefficients were over 0.68. The central frequency of the low component diminished during the manoeuvres. CONCLUSIONS: In healthy individuals, the temporal and spectral measurements of the heart rate variability from short-term records are stable in a five day period for the manoeuvres studied. Central frequencies of the spectral components might be used as indexes of the autonomic activity.