Correlation between spectral measures of systolic blood pressure variability and heart rate variability during paced breathing, standing and exercise

摘要

To provide insight on the somewhat controversial issue of the physiological correlates of spectral indexes of systolic pressure variability (SPV) we assessed the relations between them and those of heart rate variability (HRV) in 20 subjects during two sympathetic maneuvers, standing (S) and exercise (E). We also evaluated the percentage of statistical differences among 50-s epochs (PSDE) of the spectral measures dynamics obtained in 5-min steady-state conditions. From time-frequency spectra, high-frequency power of RR intervals (HFRR), low-to-high-frequency ratio (LFRR/HFRR), low-frequency of systolic pressure (LFSP), high-frequency of systolic pressure (HFSP), high-frequency of respiration (HFRe) and HFSP-HFRe time-frequency coherence were computed. LFSP-lnHFRR, LFSP-RR and LFSP-LFRR/HFRR correlations were −0.73±0.09, −0.77±0.06, and 0.66±0.13 respectively. During E, HFRR decreased, HFSP increased (p<0.001) and HFRe-HFSP coherence was 0.93±0.05. Global PSDE of the measures was 41±18%. HRV spectral measures show strong correlation with LFSP power, novel evidence that supports its suitability as sympathetic index. The differential effect of E on HFRR and HFSP and high HFSP-HFRe coherence document the mechanical respiratory origin of HFSP. Spectral measures of supposedly steady-state maneuvers present high PSDE.