title: Effects of left ventricular size on the accuracy of diastolic parameters derived from myocardial perfusion SPECT: comparison with tissue Doppler echocardiography.
abstract: BACKGROUND
  Impaired left ventricular (LV) diastolic function is a sensitive and early sign of myocardial ischemia. We evaluated the effects of LV size on the accuracy of diastolic parameters derived from SPECT.
  
  
  METHODS
  The study population consisted of 151 patients with known or suspected coronary artery disease who underwent both SPECT and transthoracic echocardiography. Peak filling rate (PFR), one-third mean filling rate (1/3 MFR) and the ratio of time to PFR to the RR interval (TPFR/RR) were calculated by quantitative gated SPECT. Peak early mitral annular velocity (e') was used as the reference standard of LV diastolic function.
  
  
  RESULTS
  There were 43 patients with end-systolic volume (ESV) of ≤10 ml, 43 patients with ESV of 11-20 ml and 65 patients with ESV of >20 ml. There were significant differences in PFR (p < 0.001), 1/3 MFR (p < 0.001) or TPFR/RR (p = 0.01) among the 3 groups. These diastolic parameters were increased with decreased LV size. In overall patients, PFR (r = 0.24, p = 0.003) and 1/3 MFR (r = 0.31, p < 0.001) were positively, and TPFR/RR (r = -0.23, p = 0.004) was inversely correlated with e'. Multivariate linear regression analyses showed that male gender (β = -0.14, p = 0.07; β = -0.16, p = 0.04), ESV (β = -0.63, p < 0.001; β = -0.45, p < 0.001) and e' (β = 0.36, p < 0.001; β = 0.40, p < 0.001) were significant factors associated with PFR or 1/3 MFR. Multivariate linear regression analysis also showed that ESV (β = -0.17, p = 0.03) and e' (β = -0.21, p = 0.01) were significant factors associated with TPFR/RR.
  
  
  CONCLUSIONS
  Our data suggest that PFR, 1/3 MFR and TPFR/RR derived from SPECT are correlated with e' as the reference standard of LV diastolic function, but are overestimated in small-sized heart. LV size should be taken into consideration when interpreting these diastolic parameters.
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan. skurisu@nifty.com.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kurisu
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Sumimoto
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ikenaga
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Ishibashi
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Dohi
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hidaka
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Fukuda
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Kihara
mesh_terms: D000368:Aged; D003971:Diastole; D015150:Echocardiography, Doppler; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008297:Male; D055414:Myocardial Perfusion Imaging; D009929:Organ Size; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging
keywords: Diastolic function; Diastolic parameter; Left ventricle; SPECT; Small heart