Research Reports in Clinical Cardiology (Jul 2021)
Sensitivity and Specificity of an Electrocardiogram to Detect Echocardiographic Left Ventricular Hypertrophy in a Sample of 326 Tanzanian Adults: Differences in Men and Women
Abstract
Pilly Chillo Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, TanzaniaCorrespondence: Pilly ChilloDepartment of Internal Medicine, Muhimbili University of Health and Allied Sciences, PO BOX 65001, Dar es Salaam, TanzaniaTel +255 22 215 0603Email [email protected]: Although an electrocardiogram (ECG) is often used as the only tool to detect left ventricular hypertrophy (LVH) in many out-patient clinics in sub-Saharan Africa (SSA), its sensitivity has been reported to be low especially among black populations, and several studies have reported gender differences. These observations have however not been widely studied among SSA blacks.Aim: To study the sensitivity and specificity of the ECG in detecting echocardiographic LVH in a sample of native adult Tanzanians.Methods: Echocardiography and 12-lead resting ECGs were performed in Tanzanian adults who participated in studies to determine the prevalence and functional consequences of abnormal left ventricular geometry in out-patients with hypertension and diabetes. ECG-LVH was determined using Sokolow-Lyon (S-L) and Cornell product (C-P) criteria, and compared with echocardiographic LVH.Results: In total, 326/425 (76.7%) participants of the original cohort had both ECG and echocardiogram measurements, and were included in this analysis. Echocardiographic LVH was present in 23.7% and 26.2% of men and women, respectively, while ECG-LVH was detected by S-L in 36.3% of men and 17.3% of women, and by C-P criteria in 20% of men and in 30.4% of women. The sensitivity [95% CI] and specificity [95% CI] of the S-L criteria was 43.8% [26.8– 62.1%] and 66.0% [55.9– 74.9%] in men while it was 36% [23.3– 50.9%] and 89% [82.8– 93.7%] in women, respectively. For the C-P criteria, the sensitivity and specificity were 43.8% [26.8– 62.1%] and 87.4% [79.0– 92.8%] in men and 60% [45.2– 73.3%] and 80.1% [89.7– 97.8%] in women, respectively.Conclusion: The sensitivity of the ECG to detect LVH is low in this population, but better than that found in many white populations. Men and women have differences in the sensitivity of the different ECG criteria, with men performing better with S-L and women with C-P criteria. These differences should be considered when including or excluding cases with ECG-LVH in our populations.Keywords: electrocardiogram, left ventricular hypertrophy, echocardiography, sensitivity, specificity, Tanzania, sub-Saharan Africa
