Evaluation of left ventricular myocardial deformation parameters in individuals with electrocardiographic early repolarization pattern

Abstract

Objective: Although an early repolarization (ER) pattern was considered to be a benign electrocardiographic variant, several studies have shown that it is associated with an increased risk of idiopathic ventricular fibrillation and death. The aim of the present study was to determine whether there is any abnormality in myocardial deformation parameters (strain, strain rate, rotation, and twist) of the left ventricle obtained by speckle-tracking echocardiography (STE) in subjects with ER pattern. Methods: There were two groups in this prospective case-control study. The first group consisted of subjects with ER pattern (n=35). The other group was control without ER pattern (n=25). Subjects with poor echocardiographic image quality and history of cardiovascular, pulmonary, systemic, or metabolic disease were excluded from the study. For STE of the left ventricle, two-dimensional images from apical long-axis, twochamber, and four-chamber views and from parasternal short-axis views were obtained. Results: We did not observe significant differences between the groups for left ventricular (LV) longitudinal deformation parameters, rotation, and twist. When LV circumferential deformation parameters were analyzed, early diastolic strain rate value at the level of apex was higher in subjects with ER pattern (2.3 +/- 0.7 s(-1) vs. 1.9 +/- 0.4 s(-1), p=0.01). Among LV radial deformation parameters, only peak strain (42.5 +/- 16.1% in the ER group vs. 56.9 +/- 21.1% in controls, p=0.004) and early diastolic strain rate (-2.0 +/- 0.7 s(-1) in the ER group vs. -2.3 +/- 0.7 s(-1) in controls, p=0.03) values at the level of papillary muscle were different. Conclusion: In subjects with ER pattern, LV myocardial deformation evaluated by STE is normal with a few regional exceptions. STE does not provide much information about risk stratification of these subjects.