Left atrial two dimensional speckle tracking echocardiography
LA images were analyzed offline via QLAB 13 Philips software for speckle tracking as depicted in Figure 1. LA deformation is a cyclical process, which can be sub-divided into three phases: a) Reservoir phase: starts at the end of ventricular diastole (mitral valve closure) and continues until mitral valve opening. It encompasses the time of LV isovolumic contraction, ejection and isovolumic relaxation, b) Conduit phase: occurs from the time of mitral valve opening through diastasis until the onset of LA contraction, c) Contraction phase: occurs from the onset of LA contraction until the end of ventricular diastole (mitral valve closure). For offline analysis of LA function, cardiac cycle was gated with ECG and kept from end-diastole to end-diastole with zero reference point taken as peak of R wave.16 After selection of appropriate image and ECG gating of cardiac cycle, software automatically traces the endocardial border of LA while manual adjustments are done to exclude pulmonary veins and LA appendage.