Theoretical Establishment of a New Algorithm for Intra-Aortic Balloon Pumping for the Patients with Atrial Fibrillation, and Its Clinical Application.

点击翻译按钮获取中文摘要

In a case with atrial fibrillation, left ventricular(LV) end-diastolic volume is regulated by LV filling time (namely, preceding R-R interval on ECG). From this view point, we devised a new algorithm that the timing of IABP balloon inflation is decided by a regression equation between preceding R-R interval and interval of R-dicrotic notch in central aortic pressure, and compared the new algorithm with other five algorithms used in commercially available drivers.[Methods] on the basis of secondary regression equations which were analyzed and established statistical goodness of fit in the 1st year of this research project, we tested this new algorithm using the ECG and central aortic pressure waves recorded simultaneously from the patients with atrial fibrillation who had undergone cardiac operation and applied intra-aortic balloon pumping immediately after the surgery. Finally, we invented a new driver for intra-aortic balloon pumping, in which the secondary regression equation between … More preceding R-R interval and R-dicrotic notch interval is calculated automatically during the periodical short stop of the intra-aortic balloon pumping and the optimal timing of balloon inflation is readjust using newly calculated equation.[Results] The secondary equations were revealed statistical significance and good fitness but the relationship between these parameters became liner in the R-R interval longer than 900 mesc. and the decisive coefficient value were distributed from 0.6 to 0.75. In the comparative study of this new algorithm with the algorithms used in commercially available drivers, the new algorithm showed most optimal timing and the standard deviation(S.D.) of timing difference between the best inflation timing (aortic dicrotic notch) and the true timing of this new algorithm showed smallest value with statistical significance compared with other five drivers. The S.D. value in new algorithm was 8.50 msec., Kontron K-2000, which had most excellent response to atrial fibrillation, showed 14.89 msec. and AVCO model-10, which had ineffective algorithm, 54.44 msec. Lastly, we made a new driver regulated by this new optimal algorithm for the patients with atrial fibrillation and applied clinically with marked hemodynamic improvements. Less