New algorithm of intra aortic balloon pumping in patients with atrial fibrillation.

Intra aortic balloon pumps have been operated inaccurately when used in patients with atrial fibrillation. In 36 pre-operative cardiac surgical patients with atrial fibrillation, the interval between the R wave of the electrocardiogram and the dicrotic notch (R-DCN interval) of the aortic pressure waveform showed significant correlation with the preceding R-R interval by second degree polynomial curves (0.53 < r2 < 0.74, p < 0.01). Based on these results a new algorithm for atrial fibrillation was designed. During brief off periods of the intra-aortic balloon pump in atrial fibrillation, electrocardiograms and aortic pressure waveforms were simultaneously recorded and analyzed to obtain a second degree polynomial curve between the preceding R-R and R-DCN intervals. The precise timing of balloon inflation was controlled using the equation in response to the preceding R-R interval. This new algorithm showed the smallest time lags (SD = 8.5 msec) when compared to other existing algorithms (the Kontron model-10, 53.49 msec; the Aries Medical model-700, 43.69 msec; the Datascope system-90, 25.98 msec; the Mansfield 3000, 19.65 msec; and the Kontron K-2000, 14.89 msec) in mock simulation driving using data obtained from clinically recorded waveforms.