Abdominal aortic wall motion of healthy and hypertensive subjects: evaluation of tissue Doppler velocity imaging

Evaluation of abdominal aortic elasticity by strain rate imaging in patients with type 2 diabetes mellitus

PURPOSE

To use strain rate imaging (SRI) to compare the abdominal aortic wall elasticity between patients with type 2 diabetes mellitus and controls.

METHODS

We measured the abdominal aorta intima-media thickness (IMT) with B-mode echography, and the anterior and posterior wall displacement (d), strain, and strain rate (SR) with SRI, in 90 patients with type 2 diabetes mellitus and 30 control subjects (group A). The patients were classified into group B (normal IMT), group C (thickened IMT), and group D (one single atheroma plaque).

RESULTS

d, strain, and SR were significantly lower in group B, C, and D than in group A (p < .05). Systolic, early-diastolic, and late-diastolic SR were lower in patients with diabetes (especially in group D) than in controls. There were significant differences in systolic SR, early-diastolic SR, and late-diastolic SR between group A and group B (p < .05).

CONCLUSIONS

SRI is a noninvasive method that can demonstrate a loss in aorta wall elasticity in patients with diabetes with normal IMT.

Aortic root dimension changes during systole and diastole: evaluation with ECG-gated multidetector row computed tomography

Cardiac pulsatility and aortic compliance may result in aortic area and diameter changes throughout the cardiac cycle in the entire aorta. Until this moment these dynamic changes could never be established in the aortic root (aortic annulus, sinuses of Valsalva and sinotubular junction). The aim of this study was to visualize and characterize the changes in aortic root dimensions during systole and diastole with ECG-gated multidetector row computed tomography (MDCT). MDCT scans of subjects without aortic root disease were analyzed. Retrospectively, ECG-gated reconstructions at each 10% of the cardiac cycle were made and analyzed during systole (30-40%) and diastole (70-75%). Axial planes were reconstructed at three different levels of the aortic root. At each level the maximal and its perpendicular luminal dimension were measured. The mean dimensions of the total study group (n = 108, mean age 56 ± 13 years) do not show any significant difference between systole and diastole. The individual dimensions vary up to 5 mm. However, the differences range between minus 5 mm (diastolic dimension is greater than systolic dimensions) and 5 mm (vice versa). This variability is independent of gender, age, height and weight. This study demonstrated a significant individual dynamic change in the dimensions of the aortic root. These results are highly unpredictable. Most of the healthy subjects have larger systolic dimensions, however, some do have larger diastolic dimensions.

The association between left ventricular diastolic dysfunction and increased aortic stiffness can be explained by possible neurohumoral mechanisms

OBJECTIVE

In our study, we tried to find an answer to the question "How could the association between left ventricular diastolic dysfunction (LVDDF) and increased aortic stiffness (IAS) be explained?"

METHODS

Cases without coronary artery disease (CAD) were divided into three groups according to their left ventricular (LV) inflow patterns and their LV basal-lateral annulus pulsed-wave tissue Doppler imaging (pw-TDI). Group 1 (n = 38) represented the normal LV inflow pattern while Group 2 (n = 54) represented impaired LV relaxation and Group 3 (n = 18) represented pseudonormalization. Aortic diameters were measured by using M-mode at a level that is 3 cm above the aortic valve. Aortic strain (AS) and aortic distensibility (AD) were calculated by using aortic diameters and pulse pressure.

RESULTS

In Group 3, AS was lower compared to Groups 1 and 2 (respectively P < 0.001, P = 0.040). AS was also lower in Group 2 compared to Group 1 (P = 0.012). AD was higher in Group 1 compared to Groups 2 and 3 (respectively P = 0.01, P < 0.001). Early diastolic velocity of aortic pw-TDI was higher in normal LV inflow compared to Groups 2 and 3 (respectively P = 0.022, P = 0.050). Unfortunately, none of echocardiographic parameters that evaluate LV and aortic functions together (stroke volume, pulse pressure/stroke volume, pulse pressure/stroke volume index) were different among the groups.

CONCLUSION

The results of our study clearly showed the association between LVDDF and IAS in cases without CAD. Additionally, it was concluded that this togetherness could be explained not by hemodynamic factors but by possible neurohumeral mechanisms.