الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 132 |  |  |
| | | from | 132 | | |
Abstract
Objectives: We explored the relationship of QT interval prolongation compared to QRS prolongation for a better prediction of LV mechanical dyssynchrony and dysfunction, in idiopathic dilated cardiomyopathy (IDC) using vector velocity imaging (VVI),.
Methods: A total of 47 patients (mean age 32±15 year) were investigated. LV deformation and mechanical (intra-LV) dyssynchrony was assessed. The SD of time from the beginning of QRS to peak longitudinal systolic strain was measured in 18 LV segments. A cutoff value > 49 ms of TTP-SD (the mean+2 SD of the value in age-matched controls) was used to define intra-LV dyssynchrony.
Results: 31(65.9%) out of 47 IDC had LV mechanical dyssynchrony. QTc interval prolongation ≥440 ms were identified in 33(70%) and QRS prolongation in 19 patients (40%).No significant difference in LV dyssynchrony, longitudinal, circumferential strain or LV twist between patients with long QT and normal QT or those with wide and narrow QRS. Using ROC curves, QRS≥ 120 shows 62% sensitivity, 100% specificity in the prediction of LV dyssynchrony. Whereas a cutoff value≥ 440 ms for QTc showed 85% sensitivity and only 33% specific in prediction of LV dyssynchrony.
Conclusion: In IDC QT interval prolongation on the surface ECG is not related intraventricular mechanical dyssynchrony or LV dysfunction and did not offer better predictor than wide QRS complex.