射血分數(英語:ejection fraction,縮寫EF)是一個心臟生理學術語,指每博輸出量(英語:Stroke volume)占心室舒張末期容積(英語:End-diastolic volume)的百分比,可分為左心室射血分數(left ventricular ejection fraction,LVEF)和右心室射血分數(right ventricular ejection fraction,RVEF)[1]。 [1]Appleton CP, Galloway JM, Gonzalez MS, Gaballa M, Basnight MA. Estimation of left ventricular filling pressures using two-dimensional and Doppler echocardiography in adult patients with cardiac disease. Additional value of analyzing left atrial size, left atrial ejection fraction and the difference in duration of pulmonary venous and mitral flow velocity at atrial contraction. Journal of the American College of Cardiology. December 1993, 22 (7): 1972–82. PMID 8245357. doi:10.1016/0735-1097(93)90787-2.