Prevalence and predictors of left ventricular hypertrophy in patients with hypertension and normal electrocardiogram

Abstract

Background: Electrocardiography (ECG) has low sensitivity for detecting left ventricular hypertrophy (LVH), while echocardiography cannot be routinely performed. Design/methods: In this study we evaluate the prevalence of LVH and diastolic dysfunction in hypertensive patients with normal ECG. We excluded patients with cardiovascular (CV) diseases, diabetes, chronic kidney disease, or presenting ECG-LVH or other ECG anomalies. The enrolled 440 hypertensive patients underwent echocardiographic examination (Acuson Sequoia 512); LV mass was indexed by body surface area (LVMI) and LVH was defined as LVMI >125 g/m2 in men and >110 g/m2 in women. Diastolic function was evaluated by mitral inflow and tissue Doppler imaging (TDI). Results: The prevalence of LVH was 8.18% (95% confidence interval [CI] 5.97–11.1%). Multiple regression analysis showed that the only variable independently associated with LVH was duration of hypertension (p<0.001). The receiver operating characteristic (ROC) curve showed that duration of hypertension was a powerful predictor of LVH, with an area under the curve (AUC) of 0.878 and p<0.0001. Further, in patients with LVH the mean difference of LVMI from the cut-off value for LVH was 12.3 9.19 g/m2. Diastolic dysfunction, defined as early diastolic myocardial velocity (Em) <0.08 m/s, was detected only in 3.2% of patients. Conclusions: The prevalence of LVH among hypertensive patients with normal ECG, free of diabetes and of CV diseases is low; moreover, patients with echocardiographic LVH presented LVMI values that identified mild LVH. Few cases of impaired diastolic function were registered. We suggest that in hypertensive patients with such characteristics the echocardiographic examination should be reserved to those who present with higher duration of hypertension.