a) Concepts behind intra-aortic balloon counterpulsation (IABCP)
Classic concept of intra-aortic balloon counter pulsation involves inflation in synchrony with aortic valve closure at the onset of isovolumic diastole and the appearance of the dicrotic notch
This displaces blood comparable to the balloons volume into the peripheral circulation during diastole
To accomplish further unloading and to prevent interference with left ventricular ejection, balloon deflation starts prior to opening of the aortic valve and the onset of LV ejection
The classic response is thus is a lowering of the systolic pressure and augmentation of the diastolic pressure
The main benefits are a decrease in afterload and increased coronary artery perfusion with secondary improvements in hemodynamics
A = Assisted systole
B = Diastolic augmentation
C = Unassisted systole
D = Unassisted aortic end-diastolic pressure
E = Dicrotic notch
F = Assisted aortic end-diastolic pressure
e) Methods can be used to trigger the IABCP
Balloon rupture should be suspected. IABCP catheter should be disconnected from console. It should then be removed (and replaced if it is still needed).
IABP is discussed in greater detail elsewhere.
Alternatively (and dangerously) one can retract the IABP until it no longer causes diminished left subclavian bloodflow.
Moulopoulos, Spyridon D., Stephen Topaz, and Willem J. Kolff. "Diastolic balloon pumping (with carbon dioxide) in the aorta—a mechanical assistance to the failing circulation." American heart journal 63.5 (1962): 669-675.
SOROFF, HARRY S., et al. "Assisted circulation II. Effects of counterpulsation on left ventricular oxygen consumption and hemodynamics." Circulation 27.4 (1963): 722-731.
Hanlon-Pena, Patricia M., and Susan J. Quaal. "Intra-aortic balloon pump timing: review of evidence supporting current practice." American Journal of Critical Care 20.4 (2011): 323-334.
Krishna, Murli, and Kai Zacharowski. "Principles of intra-aortic balloon pump counterpulsation." Continuing Education in Anaesthesia, Critical Care & Pain9.1 (2009): 24-28.
Nanas, J. N., and S. D. Moulopoulos. "Counterpulsation: historical background, technical improvements, hemodynamic and metabolic effects." Cardiology 84.3 (1994): 156-167.