The purpose of this study is to evaluate the hemodynamic derangements in patients with
ventricular premature beats (VPBs) and atrial fibrillation (Af) in relation to the interval between beat.
Subjects consisted of 30 patients (pts) with VPBs and 10 pts with Af (5 with mitral stenosis and 5
with lone Af). To evaluate hemodynamic changes with these arrhythmias, LV inflow and outflow
velocities were recorded by pulsed Doppler technique combined with 2-D echocardiography. LV
inflow volume and LV stroke volume were calculated from these Doppler recordings.
In VPBs, the significant correlation between coupling interval and %LV inflow volume of the
preceding beat or %LV stroke volume of VPB was demonstrated. The relationship between %LV
stroke volume of VPB and %LV inflow volume of the preceding beat in the same coupling interval
was significant, that would indicate the fundmental mechanism of VPB dominated by Starling's
law. In patients with decreased LV rapid filling and increased atrial contribution to LV filling,
relatively longer coupling interval resulted in little increment of LV stroke volume. This finding
suggests that not only coupling interval but also the diastolic behavior is important to evaluate the
hemodynamic changes in VPBs.
As regards Af, when the preceding R-R interval was so short as to interrupt the rapid filling
of the preceding beat, the preceding R-R interval showed a positive correlation with LV inflow volume
of the preceding beat or LV stroke volume. Whereas the preceding R-R interval was long enough
not to suppress the rapid filling of the preceding beat, they were almost constant, irrespective of the
preceding R-R interval. In patients with mitral stenosis (MS), the deceleration time of the rapid
filling was significantly longer than lone af, thereby the rapid filling in MS was more affected by the
change in preceding R-R interval compared with patients without MS.
Pulsed Doppler echocardiography was useful noninvasive technique to evaluate the left
ventricular hemodynamic changes during these arrhythmias.