Prediction of LVH from average of R wave amplitude in leads I and V5 among adult Nigerians with hypertension

Abstract

Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular events. Many methods are used to assess it but the reference standard is echocardiography. However, this facility is available only in a few hospital centres. A set of criteria based on voltage threshold as assessed by electrocardiogram, a more readily available and portable tool had been developed. This study evaluates the ability of one of the ECG criteria to predict left ventricular hypertrophy. Aim: The aim of this study was to determine the sensitivity, specificity, accuracy, positive and negative predictive values of average of R wave amplitude in leads I and V5 in predicting LVH Methodology: This is a cross-sectional descriptive study of adult hypertensive subjects. Participants were assessed for LVH using the average of R wave amplitude in lead I and V5 =18mm. Echocardiogram was used to determine their left ventricular mass index and a value greater than 125g/m2 was used as the cut off point for LVH. The sensitivity, specificity, accuracy, positive and negative predictive values were determined for the ECG criterion. Result: Ninety subjects (45 males, 45
females) participated in the study. The prevalence of LVH by echocardiogram and the ECG criterion were 32.2% and 27.8% respectively. The sensitivity, specificity, accuracy, positive and
negative predictive values for the ECG criterion were 41.9%, 79.7%, 66.7%, 52.0% and 72.3% respectively.
Conclusion: The average of R wave amplitude in leads I and V5 can reliably predict LVH among hypertensive subjects.

Key words: Sensitivity, Specificity, ECG criterion, LVH, hypertension