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.