NOVEL DETERMINATION OF VASCULAR PROPERTIES FROM BLOOD PRESSURE MEASUREMENTS TAKEN AT DIFFERENT ARM HEIGHTS: PP.14.35

Objectives: Assessing the methodology of using blood pressure (BP) variation at different arm cuff heights for the determination of the slope characterizing the linear relationship between systolic BP (SBP) and diastolic BP (DBP), which was found to have prognostic significance when determined by 24-hour ambulatory monitoring. Methods: The study population included 46 healthy subjects: M/F 25/21; age 52 ± 15 year; BP 111 ± 16/61 ± 8 mmHg. BP was measured in the sitting position with an upper-arm cuff using a digital BP monitor. BP measurements (n = 7 to 9) performed consecutively at arm postures at 3–4 different cuff center heights varying between heart to head level. At each posture, the (flexed) arm was either self-supported (17 patients) or supported comfortably by a stand with an arm support adjustable at selectable levels (29 patients). Between measurements, the arm rested at the heart level for at least about 30 sec. The test duration was 15–20 minutes. Variability of SBP and DBP was expressed by the standard deviations of SBP, SDs, and DBP, SDd, respectively. Following the principles of symmetric regression analysis, SBP-on-DBP slope was estimated by SDs/SDd, called BP Variability Ratio (BPVR). Results: Mean ± SD of the BP variability range (twice the SD values) was 20 ± 6/16 ± 4 mmHg. SBP-DBP relationship was highly linear (r = 0.952 ± 0.036). SBP-on-DBP slope was 1.18 ± 0.28 with 5 ± 2% error of determination. Data were insensitive to the use of the stand. Conclusion: Measuring BP at different arm heights is a simple and fast way for determining the SBP-on-DBP slope. While BP variability range and determination accuracy is comparable to the 24-hour ambulatory-based method, the present method is relatively “instantaneous” regarding circulatory status and potentially applicable for non-dipping and short term response to interventions, performed in resting conditions and BP variability is created passively by gravitation, hence relative stability of the arterial factor. This could also enhance reproducibility. However, outcomes variation over time, comparability with ambulatory method and prognostic significance remains to be evaluated.