Diastolic augmentation

Unassisted systolic

pressure

Assisted systolic pressure

Dicrotic Notch

Unassisted diastolic pressure

Assisted diastolic pressure

Without

augmentation

With 1:2 augmentation

Diastolic Augmentation

Dicrotic Notch

Early inflation will increase afterload as the heart must eject

blood against an inflated balloon. This inturn will result in

increased myocardial wall stress and Left ventricular end

diastolic pressure thereby increasing left ventricular work,

reducing cardiac output.

Diastolic augmentationUnassisted systolic pressure

Delayed inflation of the balloon after aortic valve closure results in inadequate

diastolic

Augmentation. There is blunting or complete lack of diastolic augmentation

waveform.

Associated with this is a lack of end-diastolic pressure decrease ( afterload

reduction) and no increase in diastolic perfusion pressure. There is a prolonged

dip or U wave then a blunted or decreased diastolic augmentation

Assisted and unassisted

Systolic pressure

Diastolic augmentation

Tracing reveals a normal diastolic augmentation but then a long drawn out

U-shaped wave prior to the assisted systolic waveform . There is inadequate

preload reduction and therefore no change in assisted and unassisted systolic pressure.

Diastolic augmentation

Assisted systolic pressure

Unassisted systolic pressure

Assisted end - diastolic pressure

Unassisted end-diastolic pressure

Late deflation of IABP causes a dramatic increase in afterload as systole begins with higher

intra-aortic pressure. This causes late opening of the aortic valve and severely reduces the

cardiac output. The pressure wave form reveals an assisted end-diastolic pressure that is higher

than the unassisted end-diastolic pressure and a drastically reduced assisted systolic pressure.