Which of the following is a physiologic effect of IAB counterpulsation?

Intra-aortic balloon counterpulsation (IABP) is a mechanical device used to support cardiac function in patients with heart failure or those undergoing certain cardiac procedures. One of the primary physiological effects of IABP is the increase in cardiac output, which is measured by cardiac index (CI).

During diastole, when the intra-aortic balloon inflates, it causes an increase in aortic diastolic pressure. This inflation provides additional blood flow to the coronary arteries, improves myocardial perfusion, and enhances the overall stroke volume during the subsequent systole when the balloon deflates. The augmented blood flow leads to an improved cardiac output, which is effectively reflected in the increase in CI.

This increase in cardiac index signifies better overall heart performance and oxygen delivery to tissues, making it a primary benefit of using IAB counterpulsation in patients experiencing heart dysfunction. The choice that identifies this effect aligns with the fundamental goal of IABP therapy—supporting and augmenting cardiac performance during critical circumstances.