Which statement best describes the difference between VA and VV ECMO?

• A. VA provides pulmonary support only; VV provides cardiac and pulmonary.
• B. VA provides cardiac and pulmonary support; VV provides pulmonary support only.
• C. VA provides cardiac support; VV provides none.
• D. VA provides no support; VV provides pulmonary support.

Answer: (B)

The key difference is what each ECMO mode supports. Venoarterial ECMO returns oxygenated blood to the arterial system, effectively bypassing both the heart and the lungs to provide circulation and gas exchange—so it offers cardiac and pulmonary support. Veno-venous ECMO returns blood to the venous system, and the heart must continue to pump it through the body, so it mainly improves gas exchange in the lungs without directly supporting the heart. Therefore, VA provides cardiac and pulmonary support, while VV provides pulmonary support only. Use VA when both heart and lung failure are present; use VV when the heart is functioning but lung failure remains.