IABP: Late Inflation

This shows the arterial tracing of Late Inflation of an IABP

Late Inflation with the IABP not inflating until well after onset of diastole is the only "safe" failure mode. Late inflation will, however, result in a decreased therapeutic effect, which, as noted previously, is at best a 10-20% increase in cardiac output.

Late inflation is safe in-so-far-as it will not acutely kill the patient by a severe rise in afterload as both early inflation, or late deflation will do. Nor will it suck the blood from the coronaries as early deflation has the potential to do.

Note here the clear dicrotic notch, with the diastolic pressure rise from IABP balloon inflation delayed until well into diastole. Deflation is normal in this tracing. This results in a decrease in both balloon-assisted diastolic pressure rise, and flow duration.

Again, recall that with normal IABP augmentation the peak diastolic pressure is higher than any systolic pressure. With late inflation, peak diastolic pressure may be only slightly greater than, or even less than, the preceding cycle's native, unassisted peak systolic pressure.

A normal IABP pressure trace is shown in the inset to the right.