Q; Intra Aortic Balloon Pump (IABP) decreases afterload via

A) a vacuum effect
B) Increasing blood supply to mesenteric vessels
C) Inflating Aortic diameter
D) Increasing blood supply to carotid arteries
E) Increasing blood supply to Right subclavian artery


Answer: A

Basic principles of IABP are unchanged since its clinical introduction. Two major effects of IABP are

1.  During inflation of IABP in diastole of heart cycle, blood is displaced to the proximal aorta 
2.   During deflation of IABP in systole of heart cycle, aortic volume, i.e afterload reduction occurs via a vacuum effect (created by rapid balloon deflation).



 Reference: 

 Weber KT, Janicki JS. Intraaortic balloon counterpulsation. A review of physiological principles, clinical results, and device safety. Ann Thorac Surg 1974; 17:602.