Baroreceptor Control and CoA (2010-2012)

 

Impact of Local Arterial Compliance and Shear Stress on Baroreceptor Function in Children with Repaired Coarctation of the Aorta

Phase contrast MRI images of the ascending and descending aorta; magnitude (top) and velocity (bottom)

Kenny D, Curtis S, Polson J, Martin RP, Wilson DG, Caputo M, Hartley Davies R, Cockcroft JR, Paton JFR, Wolf AR, Hamilton M.

Bristol Heart Institute, Medical Physics & Bioengineering, University Hospitals Bristol and Weston NHS Foundation Trust, University of Bristol, Bristol Congenital Heart Centre, and University of Wales

Aim

MRI may be used to evaluate local arterial compliance and shear stress that may influence arterial remodelling in patients with repaired  coarctation of the aorta. MRI also offers detailed data on flow volumes and velocities and has been used to evaluate wall shear stress.

Methods

Children with early repair of coarctation of the aorta (CoA) and age-matched controls underwent detailed cardiac MRI with evaluation of aortic compliance, flow and pulse wave delay. Shear stress was also calculated using a simple method.

Results

There was a significant difference in aortic arch compliance seen between the Subclavian Flap Repair subgroup and controls (p=0.02).

Conclusions

Normotensive children with early effective repair for CoA have reduced aortic compliance at the level of the aortic arch. This is associated with higher central blood pressure although no difference in aortic shear stress.

For more detailed information on this project, click here.

Velocity profile through the ascending aorta over the cardiac cycle and plot of flow vs time from trigger in the ascending and descending aorta used to calculate the pressure wave delay.