Correlation between echocardiographic left ventricular mass index and electrocardiographic variables used in left ventricular hypertrophy criteria in Chinese hypertensive patients.

INTRODUCTION: We investigated the association between echocardiographic (Echo) left ventricular mass (LVM) indexed to body surface area (LVM/BSA) or height(2.7) (LVM/H(2.7)) and electrocardiographic (ECG) variables in 546 Chinese hypertensives.

METHODS: The study group was stratified by gender and by BMI into obese (BMI > or =28 kg/m(2)), overweight (BMI > or =24 kg/m(2) and BMI <28 kg/m(2)), and healthy weight (BMI <24 kg/m(2)) subgroups. Cornell voltage, Sokolow-Lyon voltage, maximum R amplitude in V(1)-V(6), Gubner-Ungerleider voltage, and the products of these amplitude variables with QRS duration were measured.

RESULTS: None of the ECG and Echo values showed a statistically significant difference between the obese and overweight subgroup; thus, we used only one cut-off point of BMI at 24 kg/m(2) for stratification of the hypertensive population. Cornell voltage, Cornell product and LVM/BSA were only affected by gender in our study. For hypertensives with BMI > or =24 kg/m(2), Cornell product was correlated with LVM/BSA and LVM/H(2.7) most significantly: correlation coefficients were approximately 0.45 for males and 0.40 for females and the correlation trended to be stronger as LVM/BSA or LVM/H(2.7) increased. However, a few ECG variables showed a weak correlation with LVM/BSA or LVM/H(2.7) in the hypertensives without left ventricular hypertrophy (LVH). A low sensitivity and high specificity of ECG criteria for the detection of LVH were also derived using receiver operating characteristic curves.

CONCLUSIONS: We conclude that Cornell product and Cornell voltage are the most convenient predictors for LVM/BSA with stratification only by gender. They are also the best parameters for predicting LVH in obese and overweight Chinese hypertensives, whereas estimation of LVM/BSA, LVM/H(2.7) by ECG is inaccurate in Chinese hypertensives without LVH. The cut-off point of BMI=24 kg/m(2) is suitable for stratification of body weight in further studies regarding Chinese hypertensives.