The balloon is timed to inflate in diastole, thereby augmenting diastolic pressure with a resultant increase in blood flow to the coronary arteries, great vessels, and visceral organs. The balloon deflates in systole (just prior to opening of the aortic valve), thereby causing a "void" or "potential" space in the aorta that reduces LV afterload, which in turn facilitates ventricular systolic ejection and an increase in stroke volume. The decreased systolic afterload reduces LV wall stress, decreases myocardial oxygen demand, and ameliorates the effects of coronary ischemia.

References

• Fried JA, Nair A, Takeda K, et al. Clinical and hemodynamic effects of intra-aortic balloon pump therapy in chronic heart failure patients with cardiogenic shock. J Heart Lung Transplant. 2018;37:1313-1321.
• González LS, Chaney MA. Balloon pump counterpulsation part II: perioperative hemodynamic support and new directions. Anesth Analg. 2020;131:792-807.
• Nan Tie E, Dinh D, Chan W, et al. Melbourne interventional group investigators. Trends in intra-aortic balloon pump use in cardiogenic shock after the SHOCK-II trial. Am J Cardiol. 2023;191:125-132.
• Zheng XY, Wang Y, Chen Y, et al. The effectiveness of intra-aortic balloon pump for myocardial infarction in patients with or without cardiogenic shock: a meta-analysis and systematic review. BMC Cardiovasc Disord. 2016;16:148.