Early Speckle-tracking Echocardiography Predicts Left Ventricle Remodeling after Acute ST-segment Elevation Myocardial Infarction

Left Ventricular Global Function Index and the Impact of its Companion Metric

Left ventricular (LV) global function index (LVGFI) has been introduced as a volume-based composite metric for evaluation of ventricular function. The definition formula combines stroke volume (SV), end-systolic volume (ESV), end-diastolic volume (EDV) and LV mass/density. Being a dimensionless ratio, this new metric has serious limitations which require evaluation at a mathematical and clinical level. Using CMRI in 96 patients we studied LV volumes, various derived metrics and global longitudinal strain (GLS) in order to further characterize LVGFI in three diagnostic groups: acute myocarditis, takotsubo cardiomyopathy and acute myocardial infarction. We also considered the LVGFI companion (C), derived from the quadratic mean. Additional metrics such as ejection fraction (EF), myocardial contraction fraction (MCF) and ventriculo-arterial coupling (VAC), along with their companions (MCFC and VACC) were calculated. All companion metrics (EFC, LVGFIC, MCFC, and VACC) showed sex-specific differences, not clearly reflected by the corresponding ratio-based metrics. LVGFI is mathematically coupled to both EF (with R = 0.86) and VAC (R = 0.87), which observation clarifies why these metrics not only share similar prognostic values but also identical shortcomings. We found that the newly introduced LVGFIC has incremental value compared to the single use of LVGFI, EF, or GLS, when characterizing the three patient groups.

Role of Speckle Tracking in the Evaluation of Left Ventricular Remodeling After Streptokinase Infusion in Patients with Acute Anterior Myocardial Infarction

Background. Left ventricular (LV) remodeling is an adverse consequence after acute myocardial infarction.Aim. To assess the role of speckle tracking in the evaluation of LV remodeling after streptokinase infusion in patients with acute anterior ST-segment elevation myocardial infarction (STEMI).Material and methods. A total of 200 patients with first acute anterior STEMI received streptokinase as a reperfusion therapy were included. Conventional echocardiography and speckle tracking were performed within 3 days of admission and 3 months later. According to the development of LV remodeling, patients were classified into two groups. Group (I) patients with LV remodeling (60 patients) and group (II) patients without remodeling (140 patients).Results. Patients with LV remodeling had lower global longitudinal (GLS) and circumferential (GCS) strain values (-13.19±4.57 vs. -18.90±4.23 % and -13.16±4.27 vs. -17.16±3.3 %, respectively, p<0.001). GLS cutoff value of >-13.5 was shown to have the best diagnostic accuracy (sensitivity =60.0% & specificity =87.1%) in predicting LV remodeling (AUC 0.816, 95% confidence interval [CI] 0.754-0.877, p<0.001). GCS cutoff value of >-16.21 was shown to have the best diagnostic accuracy (sensitivity =75.0% & specificity =71.4%) in predicting LV remodeling (AUC 0.785, 95%CI 0.719-0.85, p<0.001).Conclusion. Speckle tracking echocardiography either longitudinal or circumferential strain has good sensitivity and specificity in predicting LV remodeling after acute myocardial infarction.

Speckle tracking analysis in intensive care unit: A toy or a tool?

The use of conventional echocardiography in the intensive care unit (ICU) is today established to assess left and right ventricular systolic function, for preload determination and procedural guidance. Next step in ICU echocardiography could be the use of novel ultrasound techniques such as strain echocardiography to assist in the management of patients with acute coronary syndrome, heart failure, or pulmonary embolism. This review has gathered the available evidence supporting the incremental value of strain in the diagnostic workup of cardiac diseases treated in ICU.