title: Determinants and improvement of electrocardiographic diagnosis of left ventricular hypertrophy in a black African population.
abstract: BACKGROUND
  Left ventricular hypertrophy (LVH) is a major cardiovascular risk factor. The electrocardiogram (ECG) has been shown to be a poor tool in detecting LVH due to cardiac and extracardiac factors. We studied the determinants and possibility of improving the test performance of the ECG in a group of Black Africans.
  
  
  METHODS
  We studied echocardiograms and electrocardiograms of 182 Cameroonian patients among whom 113 (62.1%) were having an echocardiographic LVH. Echocardiographic LVH was defined as Left Ventricular Mass Indexed to height 2.7(LVMI)>48 g/m2.7 in men, and >44 g/m 2.7 in women or Body Surface Area ≥116 g/m2 in men, and ≥96 g/m2 in women. Test performances were calculated for 6 classic ECG criteria Sokolow-Lyon, Cornell, Cornell product, Gubner-Ungerleiger, amplitudes of R in aVL, V5 and V6.
  
  
  RESULTS
  The most sensitive criteria were Cornell (37.2%) and Sokolow-Lyon index (26.5%). The most specific criteria were Gubner (98.6%), RaVL (97.1%), RV5/V6 (95.7%) and Cornell product (94.2%). The performance of the ECG in diagnosing LVH significantly increased with the severity of LVH for Cornell index (r = 0.420, p<0.0001) and Sokolow index (r = 0.212, p = 0.002). It decreased with body habitus (r = -0.248, p = 0.001) for Sokolow-Lyon index. Cornell index was less affected (age p = 0.766; body habitus: p = 0.209). After sex-specific adjustment for BMI, Cornell BMI sensitivity increased from 37.2% to 69% (r = 0.472, p<0.0001), and Sokolow-Lyon BMI sensitivity increased from 26.5% to 58.4% (r = 0.270, p<0.001).
  
  
  CONCLUSIONS
  The test performance of the ECG in diagnosing LVH is low in this Black African population, due to extracardiac factors such as age, sex, body habitus, and cardiac factors such as LVH severity and geometry. However, this performance is improved after adjustment for extracardiac factors.
authors.affiliation: Department of Internal Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon.
authors.forename: Ahmadou M
authors.initials: AM
authors.lastname: Jingi
authors.affiliation: Internal Medicine Unit, Edéa Regional Hospital, Edéa, Cameroon.
authors.forename: Jean Jacques N
authors.initials: JJ
authors.lastname: Noubiap
authors.affiliation: Centre Médical de la Trinité, Bafoussam, Cameroon.
authors.forename: Philippe
authors.initials: P
authors.lastname: Kamdem
authors.affiliation: Department of Internal Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon; Department of Internal Medicine, Yaoundé General Hospital, Yaoundé, Cameroon.
authors.forename: Samuel
authors.initials: S
authors.lastname: Kingue
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa / Q000208:ethnology; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People; D001835:Body Weight; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000208:ethnology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D055815:Young Adult