This inconsistent result may be DNA Damage inhibitor explained by a relatively low body mass index in our patients and confounding factors such as an effect of age on the arterial stiffness. The speckle tracking method has overcome some technical limitations of tissue Doppler imaging,

including angle dependency, tethering and translational effects, high signal-to-noise ratio and high measurement variability.5),6) Speckle tracking has made it possible to quantify different components Inhibitors,research,lifescience,medical of complex cardiac motions, namely longitudinal, circumferential and radial deformation and torsion. Using the speckle tracking method, our data showed that progressive vascular stiffening contributed to the impairment of systolic and diastolic regional myocardial function. Furthermore, the Inhibitors,research,lifescience,medical compensatory increases in

apical rotation and basal-to-apical twist were attenuated in patients with advanced arterial stiffening. We previously reported that hypertensive patients with normal EF had a decreased longitudinal ε and a paradoxically increased LV torsion.13) Inhibitors,research,lifescience,medical The quantitative parameters of regional myocardial function correlated with the serum concentration of TIMP-1, which controls myocardial collagen turnover. Although the precise mechanisms associated with variable changes in different types of regional function remain unclear, paradoxically increased LV torsion with normal EF has been observed in Inhibitors,research,lifescience,medical patients with diabetes, aortic stenosis and hypertrophic cardiomyopathy.14-18) Because the changes in torsion occur long before irreversible tissue damage, these may be an early indicator of systolic dysfunction. The increase in basal-to-apical twist was primarily due to the increase in basal rotation that is affected by age-related changes in diastolic filling.19) Limitations Although we excluded patients with diabetes mellitus, we included 7 patients with impaired glucose tolerance. Nevertheless, our patients

had fasting blood glucose concentrations ranging from 112 to 123 mg/dL, and all had serum HbA1C concentrations Inhibitors,research,lifescience,medical < 7.0%. Second, the current study used apical 4-chamber view to assess longitudinal ε. The lack of 2-chamber view and apical long axis view may be another found limitation of this analysis. Third, our study could not demonstrate the precise mechanism underlying increased LV twist. Although a few explanations have been proposed,15-18) it is unclear whether high torsion is a compensatory response to maintain intracavitary pressure or a secondary change in abnormal fiber structure caused by subendocardial dysfunction in a hypertensive heart with normal EF. Further investigations are needed to clarify its clinical impact on the progression of hypertensive heart disease. Conclusions In hypertensive patients with normal EF, arterial stiffness contributed to the impairment of systolic and diastolic function of the regional myocardium.