title: Adenosine Tc-99m tetrofosmin SPECT in differentiation of ischemic from nonischemic cardiomyopathy in patients with LV systolic dysfunction.
abstract: BACKGROUND
  The noninvasive differentiation of ischemic from nonischemic cardiomyopathy is clinically important. However, whether adenosine Tc-99m tetrofosmin SPECT can offer clear and accurate information was not known. The aim of this study is to investigate the usefulness of adenosine Tc-99m tetrofosmin SPECT in differentiation of ischemic from nonischemic etiology in patients with mild to severe LV systolic dysfunction and to compare the relationship between patients with mild LV systolic dysfunction and those with severe LV systolic dysfunction.
  
  
  METHODS
  Seventy-five patients with chronic heart failure (LV ejection fraction <or=50%) underwent adenosine Tc-99m tetrofosmin SPECT and coronary angiography to identify ischemia. The patients were divided into 2 groups based on the result of ejection fraction (EF); group I (44 patients) had mild LV dysfunction, LVEF >35%, group II (31 patients) had severe LV dysfunction, LVEF <or=35%. As the result of SPECT, percent abnormal myocardium was categorized into 3 groups: small defect, <10%; medium defect 10% to 20%; and large defects, >or=20%. Myocardial ischemia was defined by >or=70% stenosis in at least one vessel by coronary angiography.
  
  
  RESULTS
  : In group I, 4 (30.8%) of 13 patients with small defects, 1 (25.0%) of 5 patients with a medium defect, and 22 (84.6%) of 26 patients with large defects demonstrated myocardial ischemia documented by coronary angiography. The relationship between the extent of the SPECT defect and myocardial ischemia was statistically significant in the group I population (P < 0.001). However, in group II, 1 (33.3%) of 3 patients with small defect, 3 (33.3%) of 9 patients with medium defects, and 7 (36.8%) of 19 patients with large defects demonstrated myocardial ischemia confirmed by coronary angiography. There was no statistical relationship between the extent of the SPECT defect and myocardial ischemia in group II.
  
  
  CONCLUSIONS
  Adenosine Tc-99m tetrofosmin SPECT is a useful modality to differentiate ischemic from nonischemic etiology in patients with mild LV systolic dysfunction. However, other noninvasive approaches other this SPECT may be considered for confirming the etiology in patients with severe LV systolic dysfunction.
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Her
authors.forename: Hee Jeoung
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Jin
authors.forename: Ho Joong
authors.initials: HJ
authors.lastname: Youn
authors.forename: Ki Bae
authors.initials: KB
authors.lastname: Seung
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000368:Aged; D009202:Cardiomyopathies / Q000175:diagnosis* / Q000473:pathology; D017023:Coronary Angiography / Q000379:methods; D004452:Echocardiography / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000473:pathology; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013599:Systole; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000473:pathology*
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin