P6.12 WAVE INTENSITY ANALYSIS OF REFLECTIONS IN THE BRACHIAL ARTERY FOLLOWING CUFF OCCLUSION AND HAND WARMING

• Main Author: D. Ho
• Format: Article
• Language: English
• Published: Atlantis Press 2013-11-01
• Series: Artery Research
• Online Access: https://www.atlantis-press.com/article/125939090/view

Background: Wave intensity analysis (WIA) is a mathematical tool used to study wave reflections in the arteries. Reflections are believed to contribute to BP augmentation and are also independent predictors of cardiovascular risk. Until now, the use of this technique has been largely confined to the aorta and carotid arteries. Methods: 8 healthy subjects (age 30 ± 7.1) underwent wrist occlusion using a cuff inflated to >50mmHg suprasystolic pressure for 5min and hand warming at 55°C for 12min. Brachial artery diameter and blood flow velocity were measured using wall tracking and doppler ultrasound with an ALOKA SSD-5550 equipped with a 7.5 MHz probe. Wave intensity was calculated and reflections were quantified as the energy of the reflected wave/energy incident wave (WRI, %). Central aortic pressure following hand warming was also estimated using applanation tonometry (Sphygmocor) in separate studies. Results: Cuff inflation resulted in a significant increment in WRI from 12.4 ± 4.15% to 26.8 ± 8.34% (p=0.001) whereas a marked reduction from 16.3 ± 6.60% to 4.09 ± 1.62% followed hand warming (p=0.0017). Cuff release was immediately associated with a significant attenuation in WRI (p=0.01). Hand-warming had no significant effect on the contralateral brachial or aortic SBP or DBP compared to baseline (p=0.3, 0.08 respectively). Conclusion: Radial artery occlusion and hand warming respectively led to an augmentation and reduction in the reflected wave in the brachial artery. Hand warming was not associated with a significant change in peripheral or central BP.