Can vascular structure and function change by altering brachial artery blood flow using an external pressure cuff pulsation technique

Abstract

Purpose: There are numerous contr ibutors that cause changes to vascular structure and funct ion, most revolve around exercise. A major determinant of vascular change is shear stress, which is inf luenced by the amount of force placed on the artery. An external cuf f pulsat ion intervent ion wi l l at tempt to regulate blood f low and al ter shear st ress; this wi l l clar ify whether blood f low changes acute vascular structure and funct ion. I f proven, addi t ional rehabi l itat ion processes for individuals suf fer ing from angina or vascular damage may be benef ited. Method: Physical ly act ive males volunteered as part icipants. A non - invasive method of Flow-Mediated Di lat ion was used to assess the vascular adaptat ions before and af ter a 5-minute cuf f pulsat ion intervent ion at 60% of their systol ic blood pressure. Resul ts: A signi f icant dif ference was found when compar ing t ime to peak arter ial di lat ion (TTPAD) before and af ter the intervent ion (86.7 + 16.0 sec; 107.95 + 36.3 sec, respect ful ly). There were sl ight changes found in other var iables such as delta diameter, shear rate and arter ial diameter, however, no signi f icant di f ference was ident if ied. Moreover, blood pressure remained relat ively constant throughout the whole procedure. Conclusion: The resul ts show that a cuf f pulsat ion intervent ion increases TTPAD signi f icant ly, but has l i t t le acute ef fect on vascular response in other var iables. This may be due to the extent that the cuf f st resses the artery. In addi t ion, the avai labi l i ty of Ni tr ic Oxide, the mediator of vascular di lat ion may also play a role in the vasodi lat ion of an ar tery, as the st imulus to release Ni t r ic Oxide is too l it t le to make an ef fect and causes an increase TTPAD. Greater external pressure may therefore resul t in signi f icant ly di f ferent acute adaptat ions.