title: Midwall ejection fraction for assessing systolic performance of the hypertrophic left ventricle.
abstract: BACKGROUND
  In patients with left ventricular hypertrophy (LVH), LV midwall fractional shortening (FS) is used as a measure of LV systolic performance that is more physiologically appropriate than conventional FS. For evaluation of LV volume and ejection fraction (EF), 2-dimensional (2D) echocardiography is more accurate than M-mode echocardiography. The purpose of this study was to assess systolic performance by midwall EF using 2D speckle tracking echocardiography (STE).
  
  
  METHODS
  Sixty patients were enrolled in the study. Patients were divided into two groups with LVH (n = 30) and without LVH (control group, n = 30). LV systolic function was compared between the two groups and the relationships of left ventricular mass index (LVMI) with LV systolic parameters, including midwall EF, were investigated.
  
  
  RESULTS
  Midwall EF in the LVH group was significantly lower than that in the control group (42.8±4.4% vs. 48.1±4.1%, p <0.0001). Midwall FS was also significantly lower in the LVH group (13.4±2.8% vs. 16.1±1.5%, p <0.0001), but EF did not differ significantly between the two groups. There were significant correlations between midwall EF and LVMI (r=0.731, p <0.0001) and between midwall FS and LVMI (r=0.693, p <0.0001), with midwall EF having the higher correlation.
  
  
  CONCLUSIONS
  These results show that midwall EF can be determined using 2D STE. Midwall EF can be used to monitor LV systolic dysfunction, which is not possible with conventional EF. Evaluation of midwall EF may allow assessment of new parameters of LV systolic function in patients with LV geometric variability.
authors.affiliation: Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, 2-17-6 Ohashi, Meguro-ku, Tokyo, Japan. hisao_yskw@yahoo.co.jp
authors.forename: Hisao
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.forename: Go
authors.initials: G
authors.lastname: Hashimoto
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kusunose
authors.forename: Takenori
authors.initials: T
authors.lastname: Otsuka
authors.forename: Masato
authors.initials: M
authors.lastname: Nakamura
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sugi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*