What does ventricular unloading mean?

September 11, 2018

Ventricular unloading refers to the reduction of mechanical power expenditure of the ventricle to minimize myocardial oxygen consumption and reduce hemodynamic forces that lead to ventricular modeling.1

Myocardial oxygen consumption can be reduced by decreasing heart rate, contractility, and/or total mechanical work.1 Total mechanical work of the heart per beat is referred to as the pressure-volume area (PVA). Minimization of PVA can be achieved through lowering of ventricular systolic and diastolic volumes and pressures.1

Left ventricular support devices (Impella 2.5®, Impella CP®, and Impella 5.0®) function by aspirating blood directly from the left ventricle (LV) into the aorta, resulting in reduction of LV pressure/volume and myocardial oxygen demand, thereby providing effective ventricular unloading.2,3


  1. Uriel N, Sayer G, Annamalai S, et al. Mechanical Unloading in Heart Failure. J Am Coll Cardiol. 2018;72(5):569-580.
  2. Weber DM, Raess DH, Henriques JP, et al. Principles of Impella Cardiac Support. Cardiac Inter Today Supp. Aug/Sep 2009.
  3. Burkhoff D, Sayer G, Doshi D et al. Hemodynamics of Mechanical Circulatory Support. J Am Coll Cardiol 2015;66:2663–74.