Intra-Aortic Balloon Pump and Mechanical Circulatory Support Flashcards

The intra-aortic balloon pump (IABP) inflates at which point on the arterial waveform?

Answer: Dicrotic notch

The IABP inflates at the dicrotic notch, which represents aortic valve closure and the onset of diastole, maximizing diastolic augmentation.

Which of the following is an absolute contraindication for IABP insertion?

Answer: Significant aortic regurgitation

Significant aortic regurgitation is an absolute contraindication because IABP inflation during diastole worsens regurgitant flow back into the left ventricle.

What is the primary hemodynamic benefit of IABP counterpulsation?

Answer: Increased coronary perfusion pressure

Diastolic balloon inflation augments diastolic aortic pressure, which directly increases coronary perfusion pressure since coronaries fill during diastole.

The optimal tip position of an IABP catheter on chest X-ray is:

Answer: 2 cm distal to the left subclavian artery

The balloon tip should be positioned 2 cm distal to the left subclavian artery to avoid occluding the subclavian or carotid arteries during inflation.

IABP deflation should occur:

Answer: Just before systole (end diastole)

Deflation just before systole reduces afterload by creating a pressure void, decreasing left ventricular work during the ejection phase.

Which trigger mode for IABP is preferred when a patient has an irregular cardiac rhythm?

Answer: Arterial pressure trigger

The arterial pressure trigger is preferred in irregular rhythms because it responds directly to the arterial pressure waveform, which is more reliable than the ECG in arrhythmias.

A 1:2 IABP assist ratio is used to:

Answer: Wean the patient off IABP support

A 1:2 assist ratio (balloon inflates every other beat) is used during weaning to gradually reduce dependence on IABP support before removal.