Left ventricular function curve determined by echocardiography in patients with atrial fibrillation.

The left ventricular function curve was obtained in 14 patients with atrial fibrillation (af) by plotting the left ventricular stroke volume (SV) against end-diastolic volume (LVEDV) measured by echocardiography in 60-100 consecutive beats. Of the 14 patients, 7 had left ventricular failure due to a variety of cardiac abnormalities including CCM, perimyocarditis and AR. The other 7 patients with lone af who had normal LV function were used as normal controlsLV function curves in patients with ventricular failure were shifted downward and to the right of normal control curves. The slopes of LV function curves were decreased significantly in these patientsLV function curves shifted to the left and upwards and the slopes of the LV function curves were increased after treatment with digitalis and diuretics. In a patient with perimyocarditis and large pericardial effusion, LVEDV and SV were increased after treatment with diuretics alone, as a result of improved LV filling after disappearance of effusion. However, the LV function curve showed no shift and was situated on the extension of the curve before treatmentTo know the effect of potentiation on LVEDV-SV relation in af, endsystolic LV pressure-volume ratio was derived approximately from direct brachial artery pressure at dicrotic notch (BAP(DN))/LVESV and com-pared with the relative degree of cycle-length change. There was a significant correlation between BAP(DN)/LVESV and preceding/prepreceding RR interval, representing the possibility that the relation between LVEDV and SV in af was influenced by so-called potentiationAccordingly, LV function curve obtained from LVEDV-SV relation in af could be a modified function curve. Nevertheless, this reflects LV function documented by clinical symptoms and other widely utilized indices very well and is useful for assessing LV function