Fig. 2.

a Pulmonary arterial, venous, or left atrial vent diminish LV volume (preload) with consequent reduction in LV end-diastolic pressure (1). Reduction in LV preload at unchanged contractility will reduce LV systolic pressure (2). The LV will fail to eject if LV systolic pressure fails to exceed aortic pressure (horizontal line). b The Impella continuously drains from the LV, reducing LV volume and converts the pressure–volume loop into a triangular shape due to the loss of isovolumic phases (3). Left ventricular systolic pressure drops below aortic pressure and the LV fails to eject (4), but the Impella maintains LV output