title: Obesity markedly attenuates the validity and performance of all electrocardiographic criteria for left ventricular hypertrophy detection in a group of black African ancestry.
abstract: OBJECTIVE
  To assess the impact of obesity on the validity and performance of electrocardiographic criteria for the detection of left ventricular hypertrophy (LVH) in a group of participants of black African ancestry with a high prevalence of obesity.
  
  
  METHODS
  Electrocardiographic voltage criteria for the detection of echocardiographic LVH [left ventricular mass index (LVMI) >51 g/m²·⁷] were evaluated in 661 participants from a community sample of black African ancestry (43% obese).
  
  
  RESULTS
  BMI was inversely associated with Sokolow-Lyon voltages (partial r= -0.27, P < 0.0001) and no BMI-Cornell voltage relations were noted (P = 0.21). BMI was associated with voltage criteria that incorporate only limb lead recordings (r = 0.17-0.23), but these relations were weaker than BMI-LVMI relations (r = 0.36, P < 0.01 and P < 0.0001 for comparisons of r values). All electrocardiographic criteria were as strongly related to blood pressure as LVMI. Sokolow-Lyon voltage-LVMI relations were noted only after adjustments for BMI (P < 0.02) and Sokolow-Lyon voltages showed no performance for LVH detection. Cornell voltages showed significant performance in nonobese [area under receiver operating curve (AUC) = 0.67 ± 0.04, P < 0.0005], but not in obese (AUC = 0.56 ± 0.04, P = 0.08). Electrocardiographic criteria which employ limb-lead recordings only (e.g. RaVL) showed better performance in nonobese than in obese (AUC = 0.75 ± 0.04 and 0.59 ± 0.04, respectively, P < 0.005 for comparison) and markedly reduced specificity for LVH detection in obese (76%) than in nonobese (92%, P < 0.0001) despite similar sensitivities (32 vs. 29%).
  
  
  CONCLUSIONS
  In groups of black African ancestry, obesity contributes to a poor validity and performance of all voltage criteria for the detection of LVH. None of the current criteria are recommended for use in obesity.
authors.affiliation: Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
authors.forename: Fabian
authors.initials: F
authors.lastname: Maunganidze
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Woodiwiss
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Libhaber
authors.forename: Muzi J
authors.initials: MJ
authors.lastname: Maseko
authors.forename: Olebogeng H I
authors.initials: OH
authors.lastname: Majane
authors.forename: Gavin R
authors.initials: GR
authors.lastname: Norton
mesh_terms: D044383:Black People; D001794:Blood Pressure; D015992:Body Mass Index; D004562:Electrocardiography; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology; D008297:Male