Relationship between left ventricular torsion early after myocardial infarction and remodeling in patients with ST segment elevation myocardial infarction treated by percutaneous coronary intervention

Abstract

SUMMARY C oronary heart disease (CHD) is now the leading cause of death worldwide; it is on the rise and has become a true pandemic that respects no borders’ (Joep et al., 2012). This statement from 2009 on the website of the WHO does not differ much from the warning issued in 1969 by its Executive Board: ‘Mankind’s greatest epidemic: CHD has reached enormous proportions striking more and more at younger subjects (Schunemann et al., 2008, World Health Organization, Regional Office for Europe, 1973). Worldwide, coronary artery disease (CAD) is the single most frequent cause of death. Over seven million people every year die from CAD, accounting for 12.8% of all deaths (WHO Fact sheet N8310, 2011). The clinical presentations of CAD include silent ischaemia, stable angina pectoris, unstable angina, myocardial infarction (MI), heart failure, and sudden death (Christian et al., 2011). Atherosclerotic plaque rupture or erosion, with differing degrees of superimposed thrombosis and distal embolization resulting in myocardial underperfusion, form the basic pathophysiological mechanisms in most conditions of acute coronary syndromes (Christian et al., 2011). As a consequence, early identification of patients with LV remodeling after myocardial infarction is of vital importance for early identification of the patients at higher risk and implementation of management planes (White et al., 1987). More than 50% of the reductions seen in CHD mortality relate to changes in risk factors, and 40% to improved treatments (Joep et al., 2012). With both our continuing understanding of the new concepts of the myocardial architecture and mechanics and with the development of the new imaging techniques, there are novel parameters than can be used as a non-objective, operator independent, accurate, reproducible for measuring the myocardial functions and risk stratification of the patients. Non-Doppler, 2-dimensional (2D) speckle tacking is a new echocardiographic technique for assessment of the myocardial function. It analyzes motion by tracking speckles in the ultrasonic image in two dimensions. Current available software allows spatial and temporal image processing with recognition and selection of such elements on ultrasound image. The geometric shift of each speckle represents local tissue movement. By tracking theses speckles, various parameters that reflect the myocardial mechanics can be accurately measures and calculated. Non-Doppler 2D strain imaging is simple to perform. It requires only one cardiac cycle to be acquired; further processing and interpretation can be done after image data acquisition. Because it is not based on tissue Doppler measurements, it is angle independent. Data regarding accuracy, validity, and clinical application of non-Doppler 2D strain imaging are rapidly accumulating. This technique may prove to be of significant clinical value, enabling rapid and accurate assessment of global and segmental myocardial function (Serri et al., 2006).