Background
: Thoracic aortic aneurysm and dissection (TAAD) is the leading cause of death in patients with Marfan syndrome (MFS) and other aortic disease (AD). The natural history of AD aries significantly. The size of the aorta alone does not always predict the risks of complications, such as catastrophic TAAD.
Objectives
: We sought to develop an ultrasound technique to quantitatively measure deformation of the ascending aorta (Ao) using a real-time 2-D ultrasound speckle tracking imaging (USTI) technique to investigate:
alterations in biomechanical properties of AAo in MFS, and
early and sensitive markers for TAAD for MFS.
Methods:
A total of 40 patients (MFS: n=18, age=11.4 ± 6.2 years, versus Control: n = 22, age=10.2 ± 4.3, p = 0.46) were prospectively enrolled. Real-time 2-D echocardiography was performed. The dimension of the AAo root (at the level of aortic annulus, sinus of Valsalva (SOV), sino-tubular junction and ascending aorta) was tracked and measured continuously in the cardiac cycle to derive the maximal and minimal systolic and diastolic dimensions using USTI (Philips Medical Systems). These measurements were used to yield dimensions, strain (deformation), strain rate (rate of deformation), distensibility, stiffness index and elastic modulus.
Results:
The results were summarized in Table 1
. Compared with controls, the MFS group had significantly enlarged dimension of the AAo root (P<0.0001). In addition, the biomechanical properties were significantly altered, suggestive of reduced deformation, distensibility, elasticity and increased stiffness of the AAo root.
Conclusions:
This study demonstrated the feasibility of quantitative measurement of the biomechanical properties of the AAo in MFS using USTI. We have also shown significant deterioration of the biomechanical properties in MFS.
Table 1.
Biomechanical properties of AAO in MFS
P5451Ascending aorta wall deformation in hypertensive patients. A speckle tracking imaging study
