Sub-clinical Detection of Left Ventricular Myocardial Dysfunction in Valvular Heart Diseases: A State-of-the-Art Review in a Speckle Tracking Echocardiography and Myocardial Performance

Abstract

Purpose of the state-of-the-art review: Left ventricular (LV) global longitudinal strain (GLS) is recently recognized as a more sensitive measure of LV myocardial systolic function compared with LV ejection fraction (LVEF). In addition, left ventricular GLS , myocardial performance index (MPI) and maximum rate of LV pressure rise during isovolumetric contraction (LV dP/dtmax) are more reproducible than traditional assessment of LV systolic function by two dimensional echocardiography (2DE) LVEF. These underutilized techniques can detect preclinical myocardial dysfunction in patients who are at risk of LV failure in valvular-induced heart disease . Current guidelines for diagnosis and treatment of valvular heart disease (VHD) include LVEF as one of the parameters to take into consideration in the clinical decision-making. However, a large body of evidence has shown that left ventricular GLS, MPI and LV dP/dtmax have been classically considered as a sensitive marker of LV contractility and inotropic state. In turn GLS and myocardial performance may be a better prognosticator than LVEF in aortic and mitral valve heart diseases. This timely state-of-the-art review, appraised the evidence and role of GLS, MPI and dP/dT as clinical tools in patients with aortic and mitral valve disease. Recent findings: Left ventricular GLS has been shown to be prognostic in low-flow, low-gradient severe aortic stenosis with preserved LVEF. The role of left ventricular GLS, Tei index (MPI) and maximum rate of LV pressure rise (LV dP/dtmax) in patients with aortic regurgitation and mitral valve diseases (regurgitation and stenosis) is less well established. Summary: Echocardiography is considered the primary non-invasive imaging tool for valvular heart disease assessment and the cornerstone method in diagnosing and evaluating the morphology and severity of aortic and mitral valve diseases. Currently, diagnostic-cardiac catheterization is no more recommended except in very rare cases when echocardiographic image quality is suboptimal, non-diagnostic and when the results of 2DE are discrepant with clinical data. Once clinical decision-making is based on the 2DE and three dimensional echocardiographic in assessment of the severity of mitral and aortic valve diseases, it is crucial that standards should be adopted to maintain accuracy and consistency across echocardiographic laboratories. This illustrative review article assesses left ventricular systolic function (LVEF) employing two and/or three dimensional echocardiography in comparison to GLS, MPI and LV dP/dtmax, especially applied for aortic valve (AV) and mitral valve (MV) diseases. It is noteworthy that this document only provides echocardiographic standards rather than making recommendations for clinical management. Conclusion: It is concluded that GLS, MPI and maximum rate of LV pressure rise during isovolumetric contraction (LV dP/dtmax) are recommended and more so, they should be increasingly used to identify subclinical LV myocardial dysfunction in patients with mitral and aortic valve heart diseases, to identify optimal timing for surgery and prognosticate outcomes after surgery