Intraaortic balloon pumping during low cardiac output: validation of a mathematical model

Conventional intra-aortic balloon therapy has been of less than optimal value when used to improve cardiac output in cases of extreme heart failure. In order to determine the major factors responsible for this situation, a mathematical model was constructed. In the model it is possible to place an arbitrary size balloon within any section of aorta. The model was validated by comparing predicted cardiac output to that measured in a series of eight animal experiments. The animals were placed in a halothane-induced low-output state. Intra-aortic balloons of from 20 to 75 cc were used. With 138 observations from both model and experiment, the correlation was good (r=0.99, p<0.00001). Thus the model was considered valid for detailed investigation. Increasing the balloon displacement in the model from 40 to 100 cc can increase cardiac output from less than 10% to more than 40%. Thus this may be a way to improve device efficacy.<
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