[Left ventricular systolic blood flow dynamics and left ventricular wall motion abnormalities in atrial fibrillation]

We have already reported that, in atrial fibrillation (Af) "back flow" in the left ventricular (LV) central or apical area may occur in the cardiac cycle with a short preceding R-R interval, especially in cases with impaired LV pump function. This abnormal flow was considered to be caused by LV asynchrony. Analysis of LV wall motion abnormalities, however, is a less established procedure. The purpose of the present study was to clarify the relationship between LV blood flow dynamics and LV wall motion using pulsed Doppler echocardiography and left ventriculography. The results were as follows: 1. In seven of 15 cases "back flow" was observed in the LV central or apical area. 2. On left ventriculography in the seven cases, the apical area showed a backward movement in a longitudinal direction in the cardiac cycle with a short preceding R-R interval. 3. The % shortening of the long-axis dimension was significantly decreased in the seven cases with back flow, and three of them had negative values. 4. Ejection fractions (EF) of both the apical and basal halves were significantly decreased in cases with back flow, and the difference in the ejection rate of the apical and basal halves tended to decrease in cases with back flow. 5. LVEF was also significantly decreased in the cases with back flow. These results indicate that left ventricular "back flow" observed in Af is caused by the LV asynchrony due to localized wall motion abnormalities in the apical area.