title: Accuracy of biplane analysis of left ventricular ejection fraction based on two consecutive single plane studies.
abstract: OBJECTIVE
  Mainly due to the high costs of biplane equipment many cardiac laboratories run single plane angiographic equipment only. Consequently, a biplane ventriculogram may only be done with two consecutive single plane studies. The aim of this investigation was to assess the accuracy of a biplane analysis of two consecutive single plane studies.
  
  
  METHODS
  A total of 42 patients (62 +/- 10 years, 76% males), able to tolerate two consecutive ventriculograms without arrhythmia during the first study underwent two consecutive biplane studies (LAO 60, RA0 30), using 40 ml of contrast each. After the first injection, the x-ray tube was moved in a neutral position, and then was replaced in the 30 RAO/60 LAO position. Digital data was analyzed by two separate investigators using commercially available software.
  
  
  RESULTS
  Intra-observer variability of left ventricular ejection fraction (LVEF) showed a high degree of agreement (single plane 1 vs. 2: r = 0.98; standard error of regression (Sy.x.): 2.8); the variability was slightly higher with two investigators (single plane: r = 0.92, Sy.x: 5.5 ) and with biplane analysis (biplane 1 vs. 2: r = 0.90, Sy. x: 5.7). End-diastolic volume index (EDVI) increased significantly from the first to the second study (84 +/- 28 ml/m2 vs 87 +/- 30 ml/m2; p = 0.017): Still LVEF of the two consecutive biplane studies showed very good agreement (biplane 1 vs. 2: mean difference (MD), -1.0; standard deviation of the difference (SDD), 5.2%). This agreement was almost as good as the one of LVEF values calculated from two consecutive single plane, but biplane analyzed studies compared to simultaneous biplane studies (MD, -0.5; SDD, 4.3%).
  
  
  CONCLUSIONS
  Despite the significant increase in EDVI after contrast injection, LVEF values determined from two consecutive studies remained virtually unchanged. Biplane analysis of LVEF values based on consecutive single plane studies resulted in similar and reliable values as determined by two consecutive biplane studies.
authors.affiliation: Department of Cardiology, Universitatsspital, Petersgraben 4, CH-4031, Basel, Switzerland.
authors.forename: C A
authors.initials: CA
authors.lastname: Kaiser
authors.forename: S I
authors.initials: SI
authors.lastname: Yoon
authors.forename: C E
authors.initials: CE
authors.lastname: Zaugg
authors.forename: N
authors.initials: N
authors.lastname: Jander
authors.forename: P T
authors.initials: PT
authors.lastname: Buser
authors.forename: M E
authors.initials: ME
authors.lastname: Pfisterer
mesh_terms: D000790:Angiocardiography / Q000379:methods*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007479:Iopamidol; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D013318:Stroke Volume; D016277:Ventricular Function, Left
chemical_list: D003287:Contrast Media; D007479:Iopamidol