Performance of classic electrocardiographic criteria for left ventricular hypertrophy in an African population

ECG criteria for left ventricular hypertrophy (LVH) have been almost exclus ively elaborated and calibrated in white populations. Because several inter ethnic differences in ECG characteristics have been found, the applicabilit y of these criteria to African individuals remains to be demonstrated. We t herefore investigated the performance of classic ECG criteria for LVH detec tion in an African population. Digitized 12-lead ECG tracings were obtained from 334 African individuals randomly selected from the general population of the Republic of Seychelles (Indian Ocean). Left ventricular mass was ca lculated with M-mode echocardiography and indexed to body height. LVH was d efined by taking the 95th percentile of body height-indexed LVM values in a reference subgroup. In the entire study sample, 16 men and 15 women (preva lence 9.3%) were finally declared to have LVH, of whom 9 were of the refere nce subgroup. Sensitivity, specificity, accuracy, and positive and negative predictive values for LVH were calculated for 9 classic ECG criteria, and receiver operating characteristic curves were computed. We also generated a new composite time-voltage criterion with stepwise multiple linear regress ion: weighted time-voltage criterion = (0.2366R(aVL) +0.0551R(v5) + 0.0785S (V3) + 0.2993T(V1))xQRS duration. The Sokolow-Lyon criterion reached the hi ghest sensitivity (61%) and the R-aVL voltage criterion reached the highest specificity (97%) when evaluated at their traditional partition value. How ever, at a fixed specificity of 95%, the sensitivity of these 10 criteria r anged from 16% to 32%. Best accuracy was obtained with the R-aVL voltage cr iterion and the new composite time-voltage criterion (89% for both). Positi ve and negative predictive values varied considerably depending on the conc omitant presence of 3 clinical risk factors for LVH (hypertension, age grea ter than or equal to 50 years, overweight). Median positive and negative pr edictive values of the 10 ECG criteria were 15% and 95%, respectively, for subjects with none or I of these risk factors compared with 63% and 76% for subjects with all of them. In conclusion, the performance of classic ECG c riteria for LVH detection was largely disparate and appeared to be lower in this population of East African origin than in white subjects. A newly gen erated composite time-voltage criterion might provide improved performance. The predictive value of ECG criteria for LVH was considerably enhanced wit h the integration of information on concomitant clinical risk factors for L VH.