Variation of anatomic valve area during ejection in patients with valvularaortic stenosis evaluated by two-dimensional echocardiographic planimetry:Comparison with traditional Doppler data

Objectives. Flow variations can affect valve-area calculation in aortic ste nosis and lead to inaccuracies in the evaluation of the stenosis. Knowing t hat transvalvular how varies normally within one beat, we designed this stu dy to assess the response of the valve to intrabeat variation of flow durin g systole. Results were compared with flow derived measurements. Background. Technolog ical improvements now allow us to evaluate aortic valve area directly by sh ort axis planimetry, This offers the possibility to perform serial planimet ries during one ejection phase and analyze the intrabeat dynamic behavior o f the stenotic-aortic valve and compare these measurements with flow-derive d measurements. Methods. Forty echocardiograms displaying different degrees of aortic steno sis were analyzed by frame-by frame planimetry of the valve area from onset of opening to complete closure. Maximal-mean area, opening and closing rat es and ejection times were obtained and compared with Doppler-derived data. Results. Valve area varied during ejection. Stenotic valves opened and clos ed more slowly than normals and remained maximally open for a shorter perio d. Mean area by Doppler data corresponded more closely to maximal than to m ean-planimetered area. Duration of flow was shorter than valve opening in s everely stenotic valves, Discrepancies between Doppler-derived and two-dime nsional (2D) measurements decreased in less stenotic valves. Conclusions. Our observations reveal striking differences between the dynam ics of normal and stenotic valves. Surprisingly, Doppler-derived mean-valve area correlated better with maximal-anatomic area than with mean-anatomic area in patients with aortic stenosis. Discrepancies between duration of fl ow and valve opening could explain this phenomenon. (J Am Coll Cardiol 1998 ;32:1931-7) (C) 1998 by the American College of Cardiology.