Purpose Left atrial size, particularly left atrial volume, has been recognized as a marker of left ventricular diastolic dysfunction. Contrary to flow and tissue Doppler parameters, left atrial volume is independent of acute volume load and therefore may provide a more accurate assessment of acute and chronic left ventricular dysfunction. In addition, the measurement of left atrial volume is lack of some handicaps of tissue Doppler, including regional myocardial dysfunction in coronary artery disease and bundle branch block. In recent studies, end-systolic left atrial volume (maximal left atrial volume) was useful to predict the risk of atrial fibrillation after cardiac surgery. The short-term and long-term prognosis of acute myocardial infarction was also associated with left atrial volume. In patients with mitral regurgitation, it could be used to reliably estimate the regurgitant volume. Despite end-systolic left atrial volume provides prognostic significance in many disease entities, left atrium is filling and empty in dynamic cyclic motion, so we speculate that left atrial distensibility, defined as the percentage change of left atrial volume between end-systolic and end-diastolic phase, has more prognostic power to represent LVFP and to predict the prognosis. Based on the phenomenon of that higher LVFP, which will conduct to and stretch left atrium in diastolic phase, induces left atrial distension and makes the reduction of distensibility between end-systolic and end-diastolic phases, we had proved the logarithmic relationship between left atrial distensibility and LVFP.