25) Therefore, an alternative pacing mode or alternative pacing sites have been tested in order to prevent LV dyssynchrony and hemodynamic deterioration. Several studies have showed that either RV outflow tract (RVOT) pacing26-28) or RV septal pacing29),30) might have an advantage over classic RV apical pacing, but controversial results have also been reported.4) We could Inhibitors,research,lifescience,medical not demonstrate any significant difference of the LV dyssynchrony indices between the RV apical and septal pacing. According to the PROSPECT trial, no single echocardiographic measure of dyssynchrony may be recommended because of the poor reproducibility and moderate sensitivity of cardiac resynchronization therapy

response.31) In this study, we used various kinds of mechanical Inhibitors,research,lifescience,medical dyssynchrony parameters. However, none of the echocardiographic measures of dyssynchrony showed a significant difference according to the pacing site. One interesting finding of our study is that RV septal pacing showed better longitudinal systolic movement than did RV septal pacing. Although the resting LV EF was similar

between the groups, this difference might affect the long-term LV performance, which should be tested by Inhibitors,research,lifescience,medical another study. Study limitations The LV mechanical function and dyssynchrony could be evaluated by a recently introduced speckle-tracking imaging technique, which might provide other indices including LV twist and 2-dimensional radial strain.32) Using this relatively new technique, it might be interesting to test whether LV mechanical function or dyssynchrony indices show Inhibitors,research,lifescience,medical significant difference according to the different pacing sites. Finally, although longitudinal function was better in the septal pacing group, we could not rule out the possibility that the difference of age and sex between two groups might

affect our results. Inhibitors,research,lifescience,medical Acknowledgements This work was supported by a research grant from the Korean Society of Echocardiography 2007.
It has been known for a long time that the heart makes rotation along its long-axis and a wringing (twisting) very motion. Many investigators have made use of various different techniques to measure this twist motion and to attempt to explain its significance. Such techniques include embedding radiopaque markers in the myocardium and observing their movements through biplane cine angiography,1) and making observations with sonomicrometry in animal hearts.2) Many of these techniques are invasive, and thus unsuitable for observing the hearts of human subjects. Since the 1990s, however, techniques employing magnetic resonance imaging (MRI) www.selleckchem.com/products/DAPT-GSI-IX.html tagging have seen extensive use.3),4) While MRI has greatly furthered our understanding of the twist motion of the human heart and thereby cardiac physiology, the need for large installations and the significant costs incurred mean that the range of applications is severely restricted.