Longitudinal and circumferential strain in patients with regional LV dysfunction.

The multilayer, helical arrangement of myofibers within the left ventricular myocardium forms the fundamental basis of the complex, multidimensional deformation of the left ventricle during the cardiac cycle. Echocardiographic characterization of the different components of this dynamic process not only provides a means to quantify the myocardial contractile function but also facilitates improved understanding of the pathophysiological mechanisms. Longitudinal deformation, which is more sensitive to the cardiac pathologies and is also easier to measure, has emerged as a reliable measure of the extent of the myocardial damage and may be helpful in the diagnosis and management of the patients with regional left ventricular dysfunction. Circumferential deformation, on the other hand, is affected relatively late in the disease process and therefore serves mainly as a marker of the transmural extent of the damage.