ABC | Volume 110, Nº2, February 2018

Original Article Casali et al Short & very short-term blood pressure variability Arq Bras Cardiol. 2018; 110(2):157-165 Figure 2 – Autonomic response to standing-up maneuver as evaluated by delta indices: delta HRV (heart rate variability), delta LF/HF (low frequency/high frequency) and delta of LF of blood pressure variability (LF_BPV), calculated from HR variability, LF/HF index and LF component of BPV, respectively. Box plots (median, 25 and 75% interquartile intervals) showing comparison between controls (C, blue bars) and diabetic-hypertensive (DH, green bars) groups. * p < 0.001 and ** p = 0.009 vs. C, Mann-Whitney rank sum test. 40 20 0 –20 –40 –60 –80 Delta HRV Delta LF/HF Delta LF_BPV C DH C DH C DH 400 300 200 –200 100 0 –100 1200 1000 800 600 400 200 –200 0 * * * Table 3 – Correlation between very short- (FBPM) and short-term (24h-ABPM) BP variability parameters – Control group. 24-hour Daytime Nighttime Time-rate Coefficient of variation Standard deviation Time-rate Coefficient of variation Standard deviation Time-rate Coefficient of variation Standard deviation AT REST Total BPV R 0.236 -0.042 -0.007 -0.247 -0.585 -0.315 0.555 0.210 0.301 (P) 0.461 0.897 0.983 0.439 0.046 0.319 0.061 0.513 0.341 LF component BPV R 0.373 0.538 0.608 0.370 0.445 0.559 0.021 0.343 0.438 (P) 0.233 0.071 0.036 0.236 0.147 0.059 0.948 0.276 0.155 Alpha index R -0.127 -0.357 -0.322 -0.483 -0.592 -0.524 0.290 -0.056 0.063 (P) 0.695 0.255 0.308 0.111 0.043 0.080 0.361 0.863 0.846 AFTER SYMPATHETIC ACTIVATION (Standing‑up maneuver) Total BPV R 0.418 0.350 0.427 0.138 -0.172 0.084 0.180 0.392 0.424 (P) 0.176 0.265 0.167 0.670 0.594 0.795 0.575 0.208 0.170 LF component BPV R 0.591 0.322 0.385 0.649 0.329 0.413 -0.074 0.315 0.263 (P) 0.043 0.308 0.217 0.022 0.296 0.183 0.819 0.319 0.409 Alpha index R -0.116 -0.392 -0.322 -0.346 -0.312 -0.322 0.191 -0.503 -0.270 (P) 0.720 0.208 0.308 0.271 0.324 0.308 0.552 0.095 0.397 DELTA INDEXES (AT REST/ AFTER SYMPATHETIC ACTIVATION) Delta_HRV R -0.056 -0.070 -0.105 0.353 0.081 -0.042 -0.541 -0.168 -0.340 (P) 0.862 0.829 0.746 0.261 0.803 0.897 0.070 0.602 0.280 Delta_LF/HF R 0.636 0.000 0.217 0.857 0.385 0.392 -0.233 -0.126 0.088 (P) 0.026 1.000 0.499 0.000 0.216 0.208 0.466 0.697 0.787 Delta LF_BPV R 0.299 -0.091 -0.077 0.282 0.011 -0.035 -0.170 -0.035 -0.217 (P) 0.346 0.779 0.812 0.374 0.974 0.914 0.598 0.914 0.498 BPV: blood pressure variability, LF: low frequency, LF_BPV: LF component of BPV; FBPM: Short-Term Blood Pressure. Statistic correlation expressed as correlation coefficient (R) and significance (P), obtained by Spearman’s test. 161