Estimation of myocardial work – a new concept of non-invasive left ventricular systolic function assessment

Abstract

Assessment of left ventricular (LV) systolic function is a mandatory component of cardiovascular diseases diagnostics. In clinical practice, the main parameters are the ejection fraction and LV global longitudinal strain. Both parameters have a number of limitations, including dependence on afterload. This review describes a new technique for non-invasive assessment of global and segmental myocardial contractility based on the calculation of myocardial work by analyzing pressure-strain curves. The main advantage of the technique is the ability to take into account the afterload conditions by the traditional measurement of blood pressure on the brachial artery. The characteristics of the key parameters of the methodology (global work index, global constructive work, global effective and wasted work) as well as their normative values are presented. The stages of the analysis and the limitations of the method are described separately. The results of the main pilot studies of myocardial work parameters in various cardiovascular diseases are presented. Possibilities of the technique for characterizing LV segmental function in left bundle branch block, selection of patients for cardiac resynchronization therapy with subsequent response assessment are presented. The diagnostic and prognostic value of the parameters of myocardial work in arterial hypertension, acute and chronic forms of ischemic heart disease, hypertrophic and dilated cardiomyopathy, chronic heart failure are analyzed. The possibilities of the technique in assessing the effectiveness of therapy in patients with heart failure are described. Potential advantages of the parameters of myocardial work over other markers of LV systolic function, such as ejection fraction and global longitudinal strain, have been determined. The review is illustrated with clinical examples of the use of the technique for various cardiovascular diseases from our own practice.