Abstract 2151: Distensibility Characterization of Descending Thoracic Aortic Aneurysms Using Echocardiographic Strain and Doppler Tissue Imaging: Is Size the Only Important Character?
Background: It is known that size of aortic aneurysms correlates with the risk of rupture, however, it is not known at what point in the disease progression the aortic wall characteristics might change. As well, some large aneurysms are observed not to rupture, while some smaller aneurysms rupture. The distensibility of the aortic wall may be an important factor in the evaluation of disease progression and risk of rupture. Aortic wall movement as measured by strain and doppler tissue imaging (DTI) could provide a novel means of evaluation.
Objectives: In this study, we determine distensibility characteristics of descending thoracic aortic aneurysms using echocardiographic strain and doppler tissue imaging.
Methods: Transesophageal echocardiography was performed in 7 patients with aneurysms (2 dissections; 5 atheromas without dissection) and compared them to 7 patients without aneurysms. Patient baseline characteristics were similar. A 2mm sample volume was selected on the anterior wall of the descending thoracic aorta in short axis views at a level of aneurysmal dilatation, nonaneurysmal patient sample selection was at a similar depth. Doppler tissue velocities and longitudinal strain were measured.
Results: Mean aneurysm diameter was 4.1cm (range 3.0cm to 6.3cm). Mean DTI velocities and strain rates (SRI) were significantly different between the aneurysmal and nonaneurysmal aortas (DTI 2.1±0.4 cm/s and 4.0±1.0 cm/s, p < 0.002) (SRI 9.8±3.1 1/s and 2.5±2.0 1/s, p < 0.001). There was moderate correlation found between aneurysm size and SRI (R=0.6).
Conclusion: Strain imaging of the aorta is feasible. Further study is needed to determine the correlation of pathological aortic distensibility and risk of rupture based on these imaging modalities.