Which device directly offloads the ventricle in mechanical circulatory support?

• A. IABP
• B. Impella
• C. V-A ECMO
• D. BIVAD

Answer: (B)

Direct unloading of the ventricle means actively removing blood from the ventricle and delivering it to the systemic circulation, cutting both the pressure and volume inside the ventricle to reduce wall stress and oxygen demand. The Impella does this by being a catheter-based micro-axial pump placed across the aortic valve; its inlet sits in the left ventricle and its outlet goes into the aorta, so it continuously draws blood from the LV and ejects it into the arterial system. This direct LV unloading lowers LV end-diastolic pressure and LV volume, relieving pulmonary congestion and reducing myocardial workload. Other devices support circulation in different ways: an intra-aortic balloon pump mainly reduces afterload and improves coronary perfusion without actively siphoning LV blood; veno-arterial ECMO provides systemic oxygenation and perfusion but can raise LV afterload and isn’t a direct LV unload; a biventricular assist device supports both ventricles, which is more invasive and not as targeted to unloading the LV specifically.