Left ventricular filling pressure (LVFP) has prognostic significance in patients with heart failure. Traditionally, it should be assessed by invasive method, as cardiac catheterization and Swan-Gung catheter. In advance of new techniques and modality, echocardiography provides some useful parameters for assessing LVFP, such myocardial tissue Doppler imaging. Many articles had documented that peak velocity of early-diastolic trans-mitral inflow velocity divided by early-diastolic velocity over mitral annulus correlated closely to LVFP. However, myocardial tissue Doppler only provides the information of regional myocardium, so patients with regional wall motion abnormality, as coronary artery disease, can't be assessed by this method without handicap. In addition, conduction disturbance, like bundle branch block, also influences the result of myocardial tissue Doppler. For resolving those problems, the investigators had designed a new global parameter to assess LVFP. In the investigators prior study, left atrial distensibility correlated logarithmically to LVFP in patients with severe mitral regurgitation and also in patients with acute myocardial infarction. Left atrial distensibility provided a new viewpoint to assess left ventricular diastolic function and to predict prognosis. This time, to extend left atrial distensibility to general population received echocardiographic examination for predicting prognosis is attempted.