We have located links that may give you full text access.
CONTROLLED CLINICAL TRIAL
JOURNAL ARTICLE
A new use for maximum deflection index: Detection of intraventricular dyssynchrony.
Journal of Electrocardiology 2017 May
AIM: CRT has been shown to be very beneficial for patients with reduced LVEF, symptomatic HF and increased QRS width. But many patients do not benefit from CRT. Maximum deflection index (MDI) is a quantitive measure of the rapidity of depolarization of the myocardium. In previous studies, high MDI was found to indicate epicardial origin of ventricular tachycardia. We aimed to detect the relationship between echocardiographic intraventricular dyssynchrony and MDI.
METHODS: We included 144 patients with HF, QRS≥120ms, LBBB, NYHA II-IV, LVEF<35% and scheduled for CRT (90 male, 54 female; mean age 65.3±9.9years). Septal-lateral >60ms delay for the beginning of systolic velocity in TDI and septum-posterior >130ms delay in M-mode were accepted as intraventricular dyssynchrony. The MDI was calculated by dividing the time from onset of the QRS complex to the earliest point of maximum deflection in V5-V6 by the QRS duration.
RESULTS: Septal-lateral delay was associated with MDI and QRS width in bivariate analysis. In logistic regression analysis, MDI (beta=0,264, p=0.001) and QRS width (beta=0,177, p=0.028) were found to be independent parameters for predicting significant septal-lateral delay. MDI was also associated with significant septum-posterior delay in bivariate correlations and ROC curve (p<0.05 for all). In bivariate analysis MDI was associated with intraventricular dyssynchrony in both non-strict LBBB (r=0.261, p=0.010) and strict LBBB (r=0.305, p=0.035) groups.
CONCLUSION: MDI is closely associated with all echocardiographic intraventricular dyssynchrony parameters. We suggest that MDI may be used as a marker to detect patients with increased intraventricular dyssynchrony. It may be useful to integrate MDI to CRT patient selection procedure in order to minimize nonresponders.
METHODS: We included 144 patients with HF, QRS≥120ms, LBBB, NYHA II-IV, LVEF<35% and scheduled for CRT (90 male, 54 female; mean age 65.3±9.9years). Septal-lateral >60ms delay for the beginning of systolic velocity in TDI and septum-posterior >130ms delay in M-mode were accepted as intraventricular dyssynchrony. The MDI was calculated by dividing the time from onset of the QRS complex to the earliest point of maximum deflection in V5-V6 by the QRS duration.
RESULTS: Septal-lateral delay was associated with MDI and QRS width in bivariate analysis. In logistic regression analysis, MDI (beta=0,264, p=0.001) and QRS width (beta=0,177, p=0.028) were found to be independent parameters for predicting significant septal-lateral delay. MDI was also associated with significant septum-posterior delay in bivariate correlations and ROC curve (p<0.05 for all). In bivariate analysis MDI was associated with intraventricular dyssynchrony in both non-strict LBBB (r=0.261, p=0.010) and strict LBBB (r=0.305, p=0.035) groups.
CONCLUSION: MDI is closely associated with all echocardiographic intraventricular dyssynchrony parameters. We suggest that MDI may be used as a marker to detect patients with increased intraventricular dyssynchrony. It may be useful to integrate MDI to CRT patient selection procedure in order to minimize nonresponders.
Full text links
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app