8.10 BRACHIAL ARTERY FLOW-MEDIATED DILATATION: DIFFERENT PATTERNS OF WALL SHEAR RATE INCREASE DURING REACTIVE HYPERAEMIA

Kunihiko Aizawa; Sara Sbragi; Alessandro Ramalli; Piero Tortoli; Francesco Casanova; Carmela Morizzo; Clare Thorn; Angela Shore; Phillip Gates; Carlo Palombo

doi:10.1016/j.artres.2016.10.066

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Volume 16, Issue C, December 2016, Pages 67 - 68

8.10 BRACHIAL ARTERY FLOW-MEDIATED DILATATION: DIFFERENT PATTERNS OF WALL SHEAR RATE INCREASE DURING REACTIVE HYPERAEMIA

Authors

Kunihiko Aizawa¹, Sara Sbragi², Alessandro Ramalli³, Piero Tortoli³, Francesco Casanova¹, Carmela Morizzo², Clare Thorn¹, Angela Shore¹, Phillip Gates¹, Carlo Palombo²

¹Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Exeter, UK

²Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa, Italy

³Department of Information Engineering, University of Florence, Italy

Available Online 24 November 2016.

DOI: 10.1016/j.artres.2016.10.066 How to use a DOI?
Abstract: Background: Wall shear rate (WSR) is considered an important stimulus for flow-mediated dilatation (FMD). However, its estimation by conventional ultrasound is challenging due to inherent difficulties of velocity estimation near the arterial wall. To evaluate how WSR influences brachial artery FMD, we used a prototype Doppler ultrasound system which provides simultaneous estimates of WSR at near and far walls and continuous arterial diameter tracking.

Methods: Data from 33 young healthy individuals (27.5±4.9yrs, 19F) were analysed. FMD was assessed with a conventional reactive hyperaemia technique using Ultrasound Advanced Open Platform (ULA-OP). All acquired raw data were post-processed using custom-designed software to obtain WSR and diameter parameters.

Results: Baseline diameter and FMD were 3.29±0.45 mm and 6.54±3.54 %, respectively. During hyperaemia, we observed two distinct patterns of increased WSR: monophasic (MOP, n=15 fast increase reaching peak WSR at once) and biphasic (BIP, n=18 fast followed by slow increase before reaching peak WSR). In BIP, peak WSR (657±153 sec-1 vs 522±132 sec-1) and WSR area under the curve until peak dilation (20398±6265 au vs 13530±5592 au) were significantly greater than in MOP (both p<0.05). Absolute diameter increase was significantly greater in BIP (0.24±0.10 mm) than in MOP (0.15±0.09 mm, p<0.05). Percentage diameter increase tended to be greater in BIP (7.6±3.3 %) than MOP (5.3±3.5 %, p=0.08).

Conclusions: These results demonstrate that there are distinct WSR increase patterns during hyperaemia, and that these patterns are associated with differences in the magnitude of hyperaemic WSR. Our observations suggest that these WSR increase patterns may be associated with the subsequent brachial artery FMD response.
Open Access: This is an open access article distributed under the CC BY-NC license.

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Journal: Artery Research
Volume-Issue: 16 - C
Pages: 67 - 68
Publication Date: 2016/11/24
ISSN (Online): 1876-4401
ISSN (Print): 1872-9312
DOI: 10.1016/j.artres.2016.10.066 How to use a DOI?
Open Access: This is an open access article distributed under the CC BY-NC license.

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ris enw bib

TY  - JOUR
AU  - Kunihiko Aizawa
AU  - Sara Sbragi
AU  - Alessandro Ramalli
AU  - Piero Tortoli
AU  - Francesco Casanova
AU  - Carmela Morizzo
AU  - Clare Thorn
AU  - Angela Shore
AU  - Phillip Gates
AU  - Carlo Palombo
PY  - 2016
DA  - 2016/11/24
TI  - 8.10 BRACHIAL ARTERY FLOW-MEDIATED DILATATION: DIFFERENT PATTERNS OF WALL SHEAR RATE INCREASE DURING REACTIVE HYPERAEMIA
JO  - Artery Research
SP  - 67
EP  - 68
VL  - 16
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2016.10.066
DO  - 10.1016/j.artres.2016.10.066
ID  - Aizawa2016
ER  -

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