title: Contrast echocardiography improves the accuracy and reproducibility of left ventricular remodeling measurements: a prospective, randomly assigned, blinded study.
abstract: OBJECTIVE
  We sought to assess the impact of contrast injection and harmonic imaging, on the measure by echocardiography of left ventricular (LV) remodeling.
  
  
  BACKGROUND
  Left ventricular remodeling is a precursor of LV dysfunction, but the impact of contrast injection and harmonic imaging on the accuracy or reproducibility of echocardiography is unclear.
  
  
  METHODS
  We prospectively collected LV images by using simultaneous methods. Then, LV volumes were measured off-line, in blinded manner and in random order. The accuracy of echocardiography was determined in comparison to electron beam computed tomography (EBCT) in 26 patients. The reproducibility of echocardiography was assessed by three blinded observers with different training levels in 32 patients.
  
  
  RESULTS
  End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), as measured by EBCT (195 +/- 55, 58 +/- 24 and 137 +/- 35 ml and 71 +/- 5%, respectively) and echocardiography with harmonic imaging and contrast injection (194 +/- 51, 55 +/- 20 and 140 +/- 35 ml and 72 +/- 4%, respectively), showed no differences (all p > 0.15) and excellent correlations (all r > 0.87). In contrast, echocardiography using harmonic imaging without contrast injection underestimated the EBCT results (all p < 0.01). Reproducibility was superior with rather than without contrast injection for intraobserver and interobserver variabilities (all p < 0.001). Values measured by different observers were different without contrast injection, but were similar with contrast injection (all p > 0.18). Consequently, intrinsic patient differences represented a larger and almost exclusive proportion of global variability with contrast injection for EDV (94 vs. 79%), ESV (93 vs. 82%), SV (87 vs. 53%) and EF (84 vs. 41%), as compared with harmonic imaging without contrast injection (all p < 0.005).
  
  
  CONCLUSIONS
  For assessment of LV remodeling, echocardiography with harmonic imaging and contrast injection improved the accuracy and reproducibility, as compared with imaging without contrast injection. With contrast injection, variability was almost exclusively due to intrinsic patient differences. Therefore, when evaluation of LV remodeling is deemed important, assessment after contrast injection should be the preferred echocardiographic approach.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
authors.forename: H L
authors.initials: HL
authors.lastname: Thomson
authors.forename: A J
authors.initials: AJ
authors.lastname: Basmadjian
authors.forename: A J
authors.initials: AJ
authors.lastname: Rainbird
authors.forename: M
authors.initials: M
authors.lastname: Razavi
authors.forename: J F
authors.initials: JF
authors.lastname: Avierinos
authors.forename: P A
authors.initials: PA
authors.lastname: Pellikka
authors.forename: K R
authors.initials: KR
authors.lastname: Bailey
authors.forename: J F
authors.initials: JF
authors.lastname: Breen
authors.forename: M
authors.initials: M
authors.lastname: Enriquez-Sarano
mesh_terms: D000368:Aged; D000418:Albumins; D003287:Contrast Media; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D005466:Fluorocarbons; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D013318:Stroke Volume; D014057:Tomography, X-Ray Computed / Q000379:methods; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling
chemical_list: D000418:Albumins; D003287:Contrast Media; C099458:FS 069; D005466:Fluorocarbons