title: Reference values for left ventricular systolic synchrony according to phase analysis of ECG-gated myocardial perfusion SPECT.
abstract: BACKGROUND
  The aim of this study was to define reference values for left ventricular systolic synchrony and for the volume parameters of the left ventricle using myocardial perfusion SPECT-derived phase analysis method.
  
  
  METHODS
  We evaluated data of 433 patients who underwent myocardial perfusion SPECT/CT during January 2012-February 2013 in Kuopio University Hospital. The final study population consisted of 52 patients (aged 42-84 years) who met the criteria: (1) no previously diagnosed cardiac disease, (2) normal ECG at rest, (3) no advanced coronary artery disease in CT and 4) normal myocardial perfusion in stress/rest myocardial perfusion SPECT/CT. The severity of mechanical dyssynchrony was assessed by phase analysis of gated myocardial SPECT at stress stage after pharmacological exercise and at rest using Quantitative Gated SPECT (QGS) software. Volume parameters of the left ventricle were also assessed.
  
  
  RESULTS
  The phase histogram bandwidth at rest was 28.0 [63.7] degrees (median [95th percentile]). The standard deviation of phase histogram at rest was 7.8 [26.5] degrees. Entropy at the rest study was 54.0 [63.7] %. All left ventricular dyssynchrony parameters were statistically significantly higher at stress compared to rest. There were no statistically significant differences in dyssynchrony values between men and women. In volume parameters, reference values in male were expectedly higher than in female. Cardiac output did not differ significantly between genders.
  
  
  CONCLUSIONS
  In subjects without signs of cardiac diseases, the left ventricular systolic function is well synchronized. Phase analysis measurement does not depend on gender, age, BMI or blood pressure, but the values of dyssynchrony parameters increase during pharmacological stress.
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Hämäläinen
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.
authors.forename: Marja
authors.initials: M
authors.lastname: Hedman
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Laitinen
authors.affiliation: Heart Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Hedman
authors.affiliation: Heart Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Kivelä
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.
authors.forename: Tomi
authors.initials: T
authors.lastname: Laitinen
mesh_terms: D000241:Adenosine / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods / Q000592:standards*; D004562:Electrocardiography / Q000592:standards*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods / Q000592:standards*; D009943:Organophosphorus Compounds / Q000008:administration & dosage; D015609:Organotechnetium Compounds / Q000008:administration & dosage; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D000072098:Single Photon Emission Computed Tomography Computed Tomography / Q000592:standards*; D012984:Software; D013599:Systole; D014665:Vasodilator Agents / Q000008:administration & dosage; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014665:Vasodilator Agents; C078700:technetium tc-99m tetrofosmin; D000241:Adenosine
keywords: 99mTc-tetrofosmin; ECG; QGS software; gated SPECT; heart failure; left ventricular dyssynchrony; phase analysis