The heart is one of the target organs of hypertension. Cardiac muscle responds to an increase in afterload by developing hypertrophy. In the process of developing hypertension, the heart is exposed to a transiently, but frequent, increase in afterload. The present study was designed to test the hypothesis that left ventricular hypertrophy assessed by electrocardiography (ECG) predicts future development of hypertension.Design and Method:
Normotensive subjects who visited our hospital for a physical check-up (n = 5770; age, 52.7 ± 11.3 years) was enrolled in the present study and Sokolow-Lyon voltage and Cornell product were calculated. Left ventricular hypertrophy (LVH) was defined as a Sokolow-Lyon voltage of > 3.8 mV or a Cornell product of >2440 mm × ms. After baseline examination, subjects were followed up with the endpoint being the development of hypertension.Results:
Hypertension developed in 1029 subjects (65.2 per 1,000 person-years) during the median follow-up period of 1089 days. A Kaplan–Meier analysis demonstrated a significantly higher incidence of hypertension in subjects with LVH than in those without LVH defined by either Sokolow-Lyon voltage or Cornell product (p < 0.0001 for both). The hazard ratios for incident hypertension in subjects with LVH were 1.49 [95% confidence interval, 1.16–1.90] (Sokolow-Lyon voltage, p < 0.01) and 1.34 [1.09–1.65] (Cornell product, p < 0.01) after adjustment for possible risk factors. Furthermore, in multivariable Cox hazard analysis, where both indices were taken as continuous variables, both Sokolow-Lyon voltage and Cornell product were independent predictors of future hypertension (p < 0.0001).Conclusions:
Both Sokolow-Lyon voltage and Cornell product are novel predictors of future hypertension in the general population. The present results suggest that the heart is frequently, but transiently, exposed to an increased blood pressure before the onset of hypertension.