Ejection fraction

An ejection fraction (EF) is the volumetric fraction (or portion of the total) of fluid (usually blood) ejected from a chamber (usually the heart) with each contraction (or heartbeat). It can refer to the cardiac atrium,[1] ventricle,[2] gall bladder,[3] or leg veins,[4] although if unspecified it usually refers to the left ventricle of the heart. EF is widely used as a measure of the pumping efficiency of the heart and is used to classify heart failure types. It is also used as an indicator of the severity of heart failure, although it has recognized limitations.[5]

The EF of the left heart, known as the left ventricular ejection fraction (LVEF), is calculated by dividing the volume of blood pumped from the left ventricle per beat (stroke volume) by the volume of blood present in the left ventricle at the end of diastolic filling (end-diastolic volume). LVEF is an indicator of the effectiveness of pumping into the systemic circulation. The EF of the right heart, or right ventricular ejection fraction (RVEF), is a measure of the efficiency of pumping into the pulmonary circulation. A heart which cannot pump sufficient blood to meet the body's requirements (i.e., heart failure) will often, but not invariably, have a reduced ventricular ejection fraction.[6]

In heart failure, the difference between heart failure with a reduced ejection fraction, and heart failure with a preserved ejection fraction, is significant, because the two types are treated differently.

  1. ^ Appleton CP, Galloway JM, Gonzalez MS, Gaballa M, Basnight MA (December 1993). "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. 22 (7): 1972–82. doi:10.1016/0735-1097(93)90787-2. PMID 8245357.
  2. ^ Sonnenblick EH (July 1968). "Correlation of myocardial ultrastructure and function". Circulation. 38 (1): 29–44. doi:10.1161/01.cir.38.1.29. PMID 11712290.
  3. ^ Krishnamurthy GT, Bobba VR, Kingston E (March 1981). "Radionuclide ejection fraction: a technique for quantitative analysis of motor function of the human gallbladder". Gastroenterology. 80 (3): 482–90. doi:10.1016/0016-5085(81)90009-3. PMID 7450441.
  4. ^ Christopoulos DG, Nicolaides AN, Szendro G, Irvine AT, Bull ML, Eastcott HH (January 1987). "Air-plethysmography and the effect of elastic compression on venous hemodynamics of the leg". Journal of Vascular Surgery. 5 (1): 148–59. doi:10.1016/0741-5214(87)90205-9. PMID 3795381.
  5. ^ Cikes M, Solomon SD (June 2016). "Beyond ejection fraction: an integrative approach for assessment of cardiac structure and function in heart failure". European Heart Journal. 37 (21): 1642–50. doi:10.1093/eurheartj/ehv510. PMID 26417058.
  6. ^ Ponikowski P, Voors AA, Anker SD, Bueno H, Cleland JG, Coats AJ, et al. (July 2016). "2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: The Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC) Developed with the special contribution of the Heart Failure Association (HFA) of the ESC". European Heart Journal. 37 (27): 2129–2200. doi:10.1093/eurheartj/ehw128. PMID 27206819.