Related Experiment Videos
Flow-mediated dilatation
O T Raitakari1, D S Celermajer
1Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia.
Insights
Arterial endothelial dysfunction, a key event in atherosclerosis, can now be assessed noninvasively. This ultrasound method measures arterial changes, correlating with invasive tests and offering insights into reversibility.
Area of Science:
- Cardiovascular Medicine
- Vascular Biology
- Diagnostic Imaging
Background:
- Arterial endothelial dysfunction is a crucial early event in atherogenesis, preceding structural changes and contributing to obstructive atherosclerosis.
- Traditional methods for measuring endothelial function are invasive, limiting their use in asymptomatic individuals.
- The development of noninvasive tests is essential for studying endothelial function in broader populations.
Purpose of the Study:
- To evaluate the utility of noninvasive ultrasound-based testing for assessing arterial endothelial function.
- To compare noninvasive findings with invasive measurements and coronary atherosclerosis severity.
- To explore the potential for reversing endothelial dysfunction using various therapeutic strategies.
Main Methods:
- Utilized an ultrasound-based method to measure arterial diameter changes in response to increased shear stress.
- Assessed endothelium-dependent dilatation, a marker of endothelial function.
- Correlated noninvasive endothelial function measurements with invasive testing and coronary atherosclerosis extent.
Main Results:
- Noninvasive endothelial function testing demonstrated correlation with invasive coronary endothelial function assessments.
- The method showed correlation with the severity and extent of coronary atherosclerosis.
- This approach provided insights into the reversibility of endothelial dysfunction.
Conclusions:
- Noninvasive ultrasound assessment of endothelial function is a valuable tool for studying early atherogenesis.
- This method offers a viable alternative to invasive testing, particularly for asymptomatic subjects.
- Findings support the potential reversibility of endothelial dysfunction through pharmacological and other interventions.
Abstract:
Arterial endothelial dysfunction is one of the key early events in atherogenesis, preceding structural atherosclerotic changes. It is also important in the late stages of obstructive atherosclerosis, predisposing to constriction and/or thrombosis. Endothelial function can be measured in coronary arteries and in the periphery by measuring vasomotor function after intra-arterial infusion of pharmacologic substances which enhance the release of endothelial nitric oxide. The disadvantage of these methods is their invasive nature, which generally makes them unsuitable for studies involving asymptomatic subjects. For this reason, noninvasive tests of endothelial function have been developed. In the most widely used of these, an ultrasound-based method, arterial diameter is measured in response to an increase in shear stress, which causes endothelium-dependent dilatation. Endothelial function assessed by this method correlates with invasive testing of coronary endothelial function, as well as with the severity and extent of coronary atherosclerosis. This noninvasive endothelial function testing has provided valuable insights into early atherogenesis, as well as into the potential reversibility of endothelial dysfunction by various strategies, including pharmacological agents (lipid lowering, ACE inhibition), L-arginine, antioxidants and hormones.