Daniela Battaglia

Assessment of ascending aorta wall stiffness in hypertensive patients by tissue Doppler imaging and strain Doppler echocardiography

Background Aortic stiffness may be associated with an increased incidence of cardiovascular events and has been reported to be related to arterial wall motion velocities as measured by tissue Doppler imaging. Objective To investigate the potential clinical application of tissue Doppler imaging (TDI) for assessment of aortic function parameters in healthy and hypertensive adults. Methods 110 hypertensive and 80 healthy adults were examined. Pulse wave velocity (PWV) and augmentation index (Aix) were measured as standard parameters of arterial stiffness by an oscillometric system. Aortic M-mode and TDI parameters were measured. Aortic distensibility (D) and aortic stiffness index (SI) were calculated using accepted formulae. Anterior wall aortic expansion velocity (SAo), acceleration time (ATAo), early (EAo) and late (AAo) diastolic retraction velocity and peak systolic radial strain (εAo) were determined. Comprehensive echocardiography was performed for the assessment of left ventricular (LV) systolic/diastolic function. Results SAo, EAo and eAo were significantly lower in hypertensive subjects (p<.001, p<.001, and p<.0001, respectively). Reduced D (p<.05 vs controls) and increased PWV (p<.05 vs controls) and SI (p<.01 vs controls) were consistent with evidence of increased aortic stiffness in both male and female hypertensive patients. PWV and Aix increased and D decreased with increasing age or systolic blood pressure. Multivariate analysis showed εAo to be independently related (R2 = 0.63) to pulse pressure, LV mass index and diastolic function. Conclusion Ascending aorta TDI provides wall velocity and strain data differentiating hypertensive from healthy adults and reflecting aortic compliance changes related to age and sex and LV diastolic function.

Assessment of ascending aorta distensibility after successful coarctation repair by strain Doppler echocardiography.

BACKGROUND Increased arterial stiffness may participate in the genesis of hypertension and increase of left ventricular (LV) mass after surgical correction of coarctation of the aorta. The purpose of the current study was to assess the aortic elastic properties using Doppler tissue imaging and strain rate imaging in patients after coarctoplasty. METHODS Echocardiography with Doppler tissue/strain rate imaging capabilities was performed in 26 adult normotensive patients who had successful repair of coarctation of the aorta in infancy and in 24 control subjects. Transesophageal aortic transverse sections were imaged at the level of the proximal and distal segments to the repair site. Doppler tissue imaging wall velocities during systole (S(w)), early relaxation (E(w)), and atrial systole (A(w)) and peak systolic strain (ps epsilon) were measured in both groups. Transthoracic ascending aorta (AAo) measurements were also obtained. RESULTS In the patients with coarctoplasty, S(w) velocities and ps epsilon were significantly decreased in the proximal segments compared with control subjects. Both peak systolic blood pressure after exercise (P < .001) and pulse pressure after exercise (P < .001) were directly related to AAo wall strain. LV annular early diastolic velocity was significantly reduced compared with control subjects in patients with decreased AAo wall strain and exercise-induced hypertension (P < .001) and related to AAo wall velocity (P < .005) and strain (P < .001). In multiple linear regression analysis, only weight, study group, and AAo wall strain were correlated to LV mass index. CONCLUSIONS Patients with coarctation of the aorta have reduced proximal aortic wall velocities and strain and increased stiffness even after successful repair. This amplifies stress-induced hypertension and increases LV burden.