title: The effects of ischemia with and without remote conditioning on hyperemia induced decline in carotid-radial pulse wave velocity.
abstract: Ischemic conditioning has long held promise for preventing ischemic-reperfusion (I-R) injury. Although a number of studies have evaluated the effects of brief repeated episodes of ischemia before a prolonged ischemic episode on the cardiovascular system using clinical endpoints, more sensitive techniques by which to measure its effects are lacking. Since endothelial function is sensitive to I-R injury, flow mediated dilation of the brachial artery has been proposed for this purpose, but has significant limitations. Hyperemia normally decreases carotid to radial pulse wave velocity (PWV). Accordingly, we sought to determine the effects of I-R injury and ischemic conditioning on the hyperemic change (Δ) in PWV. We induced hyperemia by release of arterial cuff occlusion before and after ipsilateral arm I-R injury (7.5min occlusion) in 25 healthy males, age 29±6 years. The protocol was repeated on 2 occasions in combination with either pre- or post- conditioning stimuli (3× 30s contralateral arm occlusions). Hyperemia resulted in a significant decrease (-13.7%, p<.001) before but not after prolonged ischemia (-0.88%, p=0.40). I-R along with either pre- or post-ischemic conditioning restored the PWV decline (pre: -11.0%, p<0.001; post: -9.9%, p<0.001). In conclusion, 7.5min ischemia blunts the normal PWV decline produced by hyperemia. Remote pre- and post-conditioning restores this response. This technique may be useful for the assessment of novel treatment strategies and mechanisms underlying remote pre- and post-ischemic conditioning in protecting the cardiovascular system.
authors.affiliation: Division of Cardiovascular Medicine, State University of New York Downstate Medical Center, Brooklyn, NY 11203-2098, United States.
authors.forename: Nwamaka
authors.initials: N
authors.lastname: Onegbu
authors.forename: Haroon
authors.initials: H
authors.lastname: Kamran
authors.forename: Bhawna
authors.initials: B
authors.lastname: Sharma
authors.forename: Manasi
authors.initials: M
authors.lastname: Bapat
authors.forename: Stephen
authors.initials: S
authors.lastname: Littman
authors.forename: Nikhil
authors.initials: N
authors.lastname: Warrier
authors.forename: Rinkesh
authors.initials: R
authors.lastname: Patel
authors.forename: Muhammad Tanweer
authors.initials: MT
authors.lastname: Khalid
authors.forename: Louis
authors.initials: L
authors.lastname: Salciccioli
authors.forename: Jason M
authors.initials: JM
authors.lastname: Lazar
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002339:Carotid Arteries / Q000503:physiopathology*; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D057775:Ischemic Postconditioning; D019194:Ischemic Preconditioning; D008297:Male; D008365:Manometry; D009518:New York; D011673:Pulsatile Flow; D017534:Radial Artery / Q000503:physiopathology*; D015427:Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors; D034941:Upper Extremity / Q000098:blood supply*; D055815:Young Adult