[Mechanism of production of pulse deficit in atrial fibrillation: assessment by blood flow dynamics].

Pulse deficit in patients with atrial fibrillation is caused by the reduction of preload. The purpose of this study was to visualize the mechanism in view of blood flow dynamics using pulsed Doppler echocardiography. The subjects were 15 cases with atrial fibrillation and pulse deficit, and the results were as follows: 1. Simultaneous recordings of the carotid pulse wave (CPW) and blood flow at the left ventricular inflow tract indicated that, in nine of the total 15 cases, CPW disappeared from the cardiac cycle even with sufficient preceding RF in the other six cases (Group B). 2. In Group A, %RF correlated well with %CPW; however, there was poor correlation between them in Group B. Moreover, CPW was always greater than 26% if RF was greater than 50% of each mean value in Group A, but less than 25% in Group B, suggesting poor left ventricular ejection in the latter group. 3. The left ventricular ejection fraction (EF) and %fractional shortening (%FS) decreased significantly in Group B compared to those in Group A (EF; 59 +- 7 vs 41 +- 12%, p less than 0.01, %FS; 31 +- 5 vs 20 +- 6, p less than 0.01). These findings indicate that left ventricular contractility was significantly reduced in the cases with pulse deficit in Group B. 4. Systolic backward flow in the mid-ventricle caused by left ventricular asynchrony due to localized apical wall motion abnormalities was observed in all 15 cases. The heart rate during pulsed Doppler echocardiography was significantly increased in Group A as compared to that in Group B.(ABSTRACT TRUNCATED AT 250 WORDS)