Indications for intra-aortic balloon pump (IABP) support in CABG.

• A. To replace the heart entirely.
• B. To augment coronary perfusion and reduce afterload in cases of low cardiac output, cardiogenic shock, failed weaning from CPB, or ventricular dysfunction.
• C. To increase afterload.
• D. To ventilate the lungs.

Answer: (B)

IABP support in CABG is used to support the heart by improving coronary perfusion and decreasing afterload when the heart’s pumping is compromised. The device works by inflating a balloon during diastole, which raises aortic diastolic pressure and enhances blood flow to the coronary arteries, helping the myocardium recover and function more effectively after bypass. It then deflates just before systole, reducing aortic impedance and afterload, which makes it easier for the heart to pump and can raise stroke volume while lowering myocardial oxygen demand. This combination is particularly helpful in cases of low cardiac output, cardiogenic shock, failure to wean from cardiopulmonary bypass, or existing ventricular dysfunction.

It does not replace the heart, so it’s not for total cardiac replacement. It does not increase afterload—quite the opposite, it reduces afterload during systole. And it does not ventilate the lungs.