title: Perfusable tissue index obtained by positron emission tomography as a marker of myocardial viability in patients with ischemic ventricular dysfunction.
abstract: In areas of severe asynergy, the clinically important task is to identify functionally recoverable myocardium. Fourteen patients with asynergy were investigated by H2(15O) dynamic positron emission tomography imaging before revascularization. Regional myocardial blood flow (MBF) was determined and the water-perfusable tissue fraction (PTF) for each region of interest and the total anatomical tissue fraction (ATF) were estimated. The PTF/ATF was analyzed as the water perfusable tissue index (PTI). Asynergy was defined as segments with wall motion more than 2SD below than that of a normal population. An increase of >0.8SD in anterior wall segments with asynergy and an increase of >0.6 SD in inferior wall asynergy were defined as significant improvements of wall motion indicative of viable myocardium. Fifteen segments with wall motion abnormalities less than -2SD and 10 control segments were identified; 7 segments recovered and 8 segments did not. MBF was similar in both groups of segments before revascularization (0.78 +/- 0.27 vs 0.73 +/- 0.18 ml min-(-1) x g(-1), NS). The PTI in the recovered segments was significantly higher than that in the unimproved segments (0.734 +/- 0.058 vs 0.592 +/- 0.038, p<0.0001) and was similar to that of the control segments. After revascularization, the PTI correlated with the SD of wall motion (p<0.05, r=0.58). PTI may be a good predictor of contractile recovery after revascularization.
authors.affiliation: Department of Cardiology, Kanazawa Cardiovascular Hospital and Kanazawa University, Japan. i-yoko@rj8.so-net.ne.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Itoh
authors.forename: Masanobu
authors.initials: M
authors.lastname: Namura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Seki
authors.forename: Toru
authors.initials: T
authors.lastname: Asai
authors.forename: Taketsugu
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Uenishi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fujii
authors.forename: Shinichirou
authors.initials: S
authors.lastname: Fujita
authors.forename: Yujirou
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Jun
authors.initials: J
authors.lastname: Ito
authors.forename: Masami
authors.initials: M
authors.lastname: Shimizu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mabuchi
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization; D003326:Coronary Circulation / Q000502:physiology*; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000601:surgery; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009204:Myocardial Revascularization; D010104:Oxygen Radioisotopes / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology
chemical_list: D010104:Oxygen Radioisotopes