title: Planimetry and transthoracic two-dimensional echocardiography in noninvasive assessment of aortic valve area in patients with valvular aortic stenosis.
abstract: OBJECTIVE
  The aim of this study was to evaluate the reliability of transthoracic two-dimensional echocardiography in measuring aortic valve area (AVA) by planimetry.
  
  
  BACKGROUND
  Planimetry of AVA using two-dimensional transesophageal echocardiographic images has been reported to be a reliable method for measuring AVA in patients with aortic stenosis. Recent advances in resolution of two-dimensional echocardiography permit direct visualization of an aortic valve orifice from the transthoracic approach more easily than before.
  
  
  METHODS
  Forty-two adult patients with valvular aortic stenosis were examined. A parasternal short-axis view of the aortic valve was obtained with transthoracic two-dimensional echocardiography. AVA was measured directly by planimetry of the inner leaflet edges at the time of maximal opening in early systole. AVA was also measured by planimetry using transesophageal echocardiography, by the continuity equation and by cardiac catheterization (Gorlin formula).
  
  
  RESULTS
  In 32 (76%) of the 42 study patients, AVA could be detected by using the transthoracic planimetry method. There were good correlations between results of transthoracic two-dimensional echocardiographic planimetry and the continuity equation (y = 0.90x + 0.09, r = 0.90, p < 0.001, SEE = 0.09 cm2), transesophageal echocardiographic planimetry (y = 1.05x - 0.02, r = 0.98, p < 0.001, SEE = 0.04 cm2) and the Gorlin formula (y = 1.02x + 0.05, r = 0.89, p < 0.001, SEE = 0.10 cm2).
  
  
  CONCLUSIONS
  Transthoracic two-dimensional echocardiography provides a feasible and reliable method in measuring AVA in patients with aortic stenosis.
authors.affiliation: Division of Cardiology, Kobe General Hospital, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Okura
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Hozumi
authors.forename: T
authors.initials: T
authors.lastname: Akasaka
authors.forename: J
authors.initials: J
authors.lastname: Yoshikawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000473:pathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology; D004452:Echocardiography / Q000379:methods; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D015203:Reproducibility of Results