title: Gated single-photon emission computed tomography detects subendocardial ischemia in hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Patients with hypertrophic cardiomyopathy (HCM) sometimes develop subendocardial ischemia (SEI) in the left ventricle (LV). In the present study it was examined whether volumetric variables obtained by gated single-photon emission computed tomography (SPECT) are useful in detecting exercise-induced SEI in patients with HCM.
  
  
  RESULTS
  Exercise 99mTc-tetrofosmin myocardial scintigraphy was performed in 26 HCM patients having non-obstruction and mild hypertrophy with a ventricular septal thickness < or = 20 mm. SEI was quantified using software developed previously, and the results were correlated with volumetric variables obtained using Quantitative Gated SPECT software. Exercise-induced percentage change in LV end-systolic volume was higher in 9 HCM patients with SEI (25.8+/-3.1%) than in 17 patients without (10.0+/-2.5%, p=0.009), although the percentage change in LV end-diastolic volume was similar in the 2 groups. The receiver-operator characteristics curve of the percentage changes in LV end-systolic volume for the detection of SEI showed that the optimal cutoff was 17%. This cutoff point yielded a good diagnostic value for the presence of SEI with a sensitivity of 89%, specificity 82%, and likelihood ratio 5.04.
  
  
  CONCLUSIONS
  Gated SPECT technique is useful in detecting SEI during exercise in a select population of HCM patients.
authors.affiliation: Department of Cardiology, Matsushita Memorial Hospital, Moriguchi, Osaka, Japan. js-k@wf6.so-net.ne.jp
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Akakabe
authors.forename: Michiyo
authors.initials: M
authors.lastname: Yamano
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Miki
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Kamitani
authors.forename: Toshiro
authors.initials: T
authors.lastname: Kuribayashi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sugihara
mesh_terms: D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000503:physiopathology; D004452:Echocardiography; D004562:Electrocardiography; D015444:Exercise; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology*; D012680:Sensitivity and Specificity; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon