Effects of gravity-induced upper-limb blood pressure changes on wave transmission and arterial radial waveform

• Published in: Journal of hypertension Vol. 34; no. 6; p. 1091
• Main Authors: Pucci, Giacomo, Battista, Francesca, Anastasio, Fabio, Sanesi, Leandro, Gavish, Benjamin, Butlin, Mark, Avolio, Alberto, Schillaci, Giuseppe
• Format: Journal Article
• Language: English
• Published: England 01.06.2016
• Subjects: Adult; Aged; Arterial Pressure; Blood Pressure Determination - methods; Brachial Artery - physiology; Female; Gravitation; Heart Rate; Humans; Male; Middle Aged; Posture; Pulse Wave Analysis; Radial Artery - physiology; Upper Extremity - physiology; Young Adult
• ISSN: 1473-5598
• DOI: 10.1097/HJH.0000000000000931

Local blood pressure (BP) changes induced by arm tilting may influence pressure wave transmission and reflection. We investigated the effects of upper-limb tilting on radial augmentation index (rAIx) and related central measures [aortic augmentation index (aAIx)]. In 45 volunteers (age 49 ± 19 years), supine brachial BP and radial artery waveforms were obtained by applanation tonometry with the dominant arm stretched and gently supported in three different positions: at the heart level, with the BP cuff 15 cm above heart level (approximately +30°), and 15 cm below heart level (-30°). Brachial SBP/DBP was 120/68 ± 17/8 mmHg. Mean arterial pressure changed predictably with arm tilting (99 ± 12 mmHg at -30°, 88 ± 10 mmHg at 0°, 77 ± 11 mmHg at +30°, all P < 0.001). rAIx decreased at -30° (69 ± 22%), and increased at +30° (93 ± 20%) compared with 0° (82 ± 20%, all P less than 0.001). Changes in rAIx (value at +30° minus value at -30°) showed an inverse relationship with age (r = -0.32, P = 0.03). Heart rate, BP and rAIx did not change in the contralateral arm, which was held at the heart level during the examination. aAIx followed the same pattern as rAIx (123 ± 27% at -30°, 144 ± 33% at +30°, 136 ± 31% at 0°, all P less than 0.001); changes in rAIx and aAIx were strongly related each other (r = 0.82, P < 0.001). Acute gravitational upper-limb BP changes generate opposite, profound changes in rAIx, and major artifactual changes in aAIx. These findings provide a rationale for recommending to keep the upper limb at the heart level during radial waveform assessment.