Which waveform feature is most indicative of late deflation on IABP tracing?

Which waveform feature is most indicative of late deflation on IABP tracing?

• A. Slurred upstroke
• B. Balloon still inflated during LV ejection
• C. Assisted systolic higher than unassisted
• D. Possible widened waveform

Answer: (C)

Late deflation reduces the intended afterload reduction, so the heart has to generate more pressure to eject against an inflated balloon during systole. On the IABP tracing, this shows up as the assisted systolic peak being higher than the unassisted peak. That relative increase in assisted systolic pressure is the most telling waveform sign that deflation is occurring late. Other signs like a slurred upstroke or a widened waveform can come from damping or tracing issues and don’t specifically indicate late deflation, while the balloon still inflating during LV ejection describes the problem in timing, but the key diagnostic cue is the higher assisted systolic pressure compared with unassisted.

Late deflation reduces the intended afterload reduction, so the heart has to generate more pressure to eject against an inflated balloon during systole. On the IABP tracing, this shows up as the assisted systolic peak being higher than the unassisted peak. That relative increase in assisted systolic pressure is the most telling waveform sign that deflation is occurring late. Other signs like a slurred upstroke or a widened waveform can come from damping or tracing issues and don’t specifically indicate late deflation, while the balloon still inflating during LV ejection describes the problem in timing, but the key diagnostic cue is the higher assisted systolic pressure compared with unassisted.