Mechanical dispersion and global longitudinal strain by speckle tracking echocardiography: Predictors of appropriate implantable cardioverter defibrillator therapy in hypertrophic cardiomyopathy

Abstract

Purpose: In this study, we investigated whether mechanical dispersion which reflects electrical abnormality and other echocardiographic and clinic parameters predict appropriate ICD shock in patients undergone ICD implantation for hypertrophic cardiomyopathy.

Methods: Sixty-three patients who received ICD implantation for primary or secondary prevention were included in the study. Patients' clinical, electrocardiographic, 2D classic, and speckle tracking echocardiographic data were collected. Mechanical dispersion was defined as the standard deviation of time to peak negative strain in 18 left ventricular segments. Appropriate ICD therapy was defined as cardioversion or defibrillation due to ventricular tachycardia or fibrillation. Patients were divided into two groups as occurrence or the absence of appropriate ICD therapy.

Results: A total of 17 (26.9%) patients were observed to have an appropriate ICD therapy during follow-up periods. In patients who performed appropriate ICD therapy, a larger left atrial volume index, higher sudden cardiac death (SCD)-Risk Score, longer mechanical dispersion, and decreased global longitudinal peak strain (GLPS) were observed. In multivariate logistic regression analysis, including (GLPS, mechanical dispersion, LAVi, and SCD-Risk Score) was used to determine independent predictors of occurrence of appropriate ICD therapy during the follow-up. Mechanical dispersion, GLPS, and SCD-Risk Score were found to be independent predictors of occurrence of appropriate ICD therapy.

Conclusions: Mechanical dispersion, GLPS, and SCD-Risk Score were found to be predictive for appropriate ICD therapy in patients receiving ICD implantation. Readily measurable mechanical dispersion and GLPS could be helpful to distinguish patients at high risk who could optimally benefit from ICD therapy.

Keywords: electromechanical delay; hypertrophic cardiomyopathy; myocardial strain.