New index of regional arterial stiffness assessed by tissue Doppler imaging.

BACKGROUND

Although brachial-ankle pulse wave velocity is a widely used index of arterial stiffness, there are several limitations of this method. The actual length of an artery used for measuring pulse wave velocity is estimated based on an anatomical correction value, and brachial-ankle pulse wave velocity is directly affected by systemic blood pressure or vascular occlusion. Thus, the aim of this study was to determine whether aortic wall strain rate as measured by tissue Doppler imaging is a more useful modality for evaluating regional arterial stiffness than brachial-ankle pulse wave velocity.

METHODS

Seventy-two patients (18 to 78 years) with normal cardiac function and without large vessel complications were enrolled in this study.

RESULTS

A significant positive correlation was found between brachial-ankle pulse wave velocity and age, and brachial-ankle pulse wave velocity increased with age (r = 0.64, P < 0.0001).A significant negative correlation was found between strain rate and age, and strain rate decreased with age (r = -0.44, P < 0.05). A significant correlation was also found between brachial-ankle pulse wave velocity and systolic blood pressure (r = 0.45, P < 0.02), but not between strain rate and systolic blood pressure.There was no significant difference in brachial-ankle pulse wave velocity between hyperlipidaemic and normolipidaemic subjects. However, strain rate was lower in hyperlipidaemic than in normolipidaemic subjects (P < 0.05).

CONCLUSION

Strain rate on the ascending aortic wall is a novel and more accurate index of regional arterial stiffness than brachial-ankle pulse wave velocity.