Validation of the local shortening function as assessed by nonfluoroscopicelectromechanical mapping: a comparison with computerized left ventricularangiography

Background: Nonfluoroscopic electromechanical mapping (NEM) has been propos ed as a new technique for the evaluation of electrical and mechanical funct ioning of the myocardium. In this system, linear local shortening (LLS) is the parameter used for assessment of local mechanical properties. To valida te this parameter, we compared LLS with regional wall motion (RWM) data der ived from contrast left ventriculograms acquired in the same patients. Meth ods and results: Angiographic left ventricular RWM was analyzed using the a rea-length method. The right anterior oblique view was divided in five segm ents, the left anterior oblique view in two. Through a comparison of enddia stolic and endsystolic areas drawn from a computer-defined central point to the respective wall delineation, RWM was calculated as change in area. In the first approach, we compared area changes to comparable NEM segments. In the second part of the study. LLS values for normokinetic, hypokinetic, ak inetic and dyskinetic segments were correlated to the change in angiographi c RWM. In the first approach, the overall comparison of segments yielded a correlation coefficient of 0.67 (P<0.0005). In the second part of the study , differences in LLS values between dyskinetic (LLS=-3.68+/-8.86%), akineti c (2.84+/-3.96%), hypokinetic (9.35+/-4.27%) and normokinetic (13.66+/-7.98 %) segments were highly significant (overall ANOVA: P<0.0005). Conclusion: NEM is a powerful tool for invasive electromechanical assessment of myocard ial function. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.