title: Gated single photon emission tomography MIBI stress perfusion imaging for assessing cardiac output and index in obese and non-obese patients.
abstract: OBJECTIVE
  To compare cardiac index, (CI) [i.e. Cardiac output (CO) corrected for body surface area], stroke volume index (SVI) and left ventricular ejection fraction (LVEF) of obese and non obese patients using gated Gated Single Photon Emission Computed Tomography (SPECT) MIBI perfusion imaging. This was done in order to assess haemodynamic function, represented by CI and systolic function represented by LVEF and SVI.
  
  
  METHODS
  Forty-one obese patients (BMI >30, mean 35.3) with 65 patients with BMI <30, (mean 25.8), referred for evaluation of chest pain, dyspnoea or inconclusive exercise ECG were studied in an outpatient setting following injection of 400MBq Tc99mMIBI. Gated SPECT imaging was performed after treadmill Bruce protocol. CO was calculated as product of SV and resting heart rate and CI determined.
  
  
  RESULTS
  Mean CI was 2.26 l/min/m(2) for obese and 2.18 l/min/m(2) for non obese patients. T tests showed no significant difference in mean CI or in SV between the two groups although CO was significantly increased for the obese group. LVEF was elevated in the obese group, mean LVEF 62.5% compared with mean LVEF of 58% in the non obese group (P < 0.05). SVI was reduced for the obese group (P < 0.03).
  
  
  CONCLUSIONS
  Haemodynamic function, as CI, was similar for obese and non-obese patients. Hypersystolic function, manifest as relatively increased LVEF, was noted in the obese group.
authors.affiliation: Department of Nuclear Medicine, Lancashire Teaching Hospitals NHS Trust, Royal Preston Hospital, Fulwood, Preston, PR2 9HT, UK. John.Coffey@lthtr.nhs.co.uk
authors.forename: J P
authors.initials: JP
authors.lastname: Coffey
authors.forename: J C
authors.initials: JC
authors.lastname: Hill
mesh_terms: D000328:Adult; D000368:Aged; D000553:Ambulatory Care; D015992:Body Mass Index; D016022:Case-Control Studies; D002637:Chest Pain / Q000000981:diagnostic imaging / Q000209:etiology; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology; D009765:Obesity / Q000150:complications*; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D017256:Technetium Tc 99m Sestamibi