Determinants of anterior mitral leaflet fluttering in pure aortic regurgitation from pulsed Doppler study of the early diastolic interaction between the regurgitant jet and mitral inflow

Abstract

Fluttering of the anterior mitral leaflet may be absent in patients with moderate to severe aortic regurgitation (AR), suggesting that the volumetric severity of AR alone does not determine the presence or absence of abnormal diastolic mitral valve motion. Fifteen patients with moderate to severe AR and normal mitral valves, 9 of whom demonstrated anterior mitral leaflet fluttering, were studied to elucidate the determinants of abnormal anterior mitral leaflet motion in these patients. Pulsed Doppler mapping of the flow-velocity disturbance of AR demonstrated its presence in the third of the left ventricular outflow tract adjacent to the anterior mitral leaflet in 8 of 9 patients with anterior mitral leaflet fluttering and none of the 6 patients without anterior mitral leaflet fluttering (p < 0.02). The impact of this regurgitant jet on early diastolic transmitral inflow was examined with pulsed Doppler in these 2 groups of patients with AR and in age-matched control subjects. Deceleration of early diastolic transmitral filling was slower in patients with AR and anterior mitral leaflet fluttering than in age-matched control subjects (283 ± 107 vs 457 ± 176 cm/s 2, p < 0.02), whereas it was not significantly different from controls in AR patients without anterior mitral leaflet fluttering. This resulted in significant prolongation of the duration of early diastolic transmitral filling in patients with AR and anterior mitral leaflet fluttering (297 ± 93 vs 203 ± 44 ms for age-matched control subjects, p < 0.02), which was not observed in patients with AR who did not have anterior mitral leaflet fluttering. Thus, in patients with moderate to severe AR, fluttering of the anterior mitral leaflet occurs in a subset of patients in whom the flow-velocity disturbance is directed onto the anterior mitral leaflet, resulting in alterations of early diasolic mitral flow velocities compatible with relative obstruction to mitral inflow.