Obesity markedly attenuates the validity and performance of all electrocardiographic criteria for left ventricular hypertrophy detection in a group of black African ancestry
Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, University of the Witwatersrand Medical School, 7 York Road, Parktown 2193, Johannesburg, South Africa; School of Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
Aim: 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/m] 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%). Conclusion: 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. © 2013 Wolters Kluwer Health | Lippincott Williams Wilkins.
hemoglobin A1c; area under the curve; article; blood glucose monitoring; body mass; community sample; diabetes mellitus; echocardiography; electric potential; electrocardiography; female; heart left ventricle hypertrophy; heart left ventricle mass; human; hypertension; major clinical study; male; Negro; obesity; priority journal; sensitivity and specificity; systolic blood pressure; validity; African Continental Ancestry Group; Blood Pressure; Body Mass Index; Electrocardiography; Female; Humans; Hypertrophy, Left Ventricular; Male