Association between persistent pressure overload and ventricular arrhythmias in essential hypertension

Hypertension is a risk factor for sudden cardiac death, and some data indicate that frequent and complex ventricular arrhythmias may be additional risk markers in hypertensive individuals. We investigated the relation between ventricular arrhythmias and the persistence of increased blood pressure levels over 24 hours in subjects with essential hypertension. We studied 126 never-treated subjects with essential hypertension (83 men) who underwent 24-hour electrocardiographic monitoring, 24-hour ambulatory blood pressure monitoring, and echocardiography. Premature ventricular beats were detected in 71% of the subjects. Compared with subjects in Lown class 0-1, subjects with frequent or complex ventricular arrhythmias (Lown class greater than or equal to 2) were older (54 versus 45 years) and had a longer duration of hypertension (5.4 versus 2.8 years), a greater left ventricular mass (147 versus 127 g . m(-2)), and a blunted nocturnal reduction in ambulatory blood pressure (7%/12% versus 12%/16%). The number of premature ventricular beats over 24 hours was associated with age (r = .25), left ventricular mass (r = .24), and pulse pressure (r = .18) and inversely associated with the percent reduction in blood pressure from day to night (r = -.29 for systolic and -.25 for diastolic pressures). In a multiple logistic regression analysis, frequent or complex ventricular arrhythmias (Lown class greater than or equal to 2) were predicted by an age greater than or equal to 60 years (odds ratio, 10.4; 95% confidence interval, 2.4-44.8), left ventricular hypertrophy at echocardiography (odds ratio, 4.2; 95% confidence interval, 1.5-11.6), and a < 10% reduction in blood pressure from day to night (''nondipping'' pattern: odds ratio, 2.9; 95% confidence interval, 1.2-7.0). We conclude that in addition to the strong effect of age and left ventricular hypertrophy at echocardiography, the persistence of high blood pressure levels over the 24 hours (''nondipping'' pattern) is an independent predictor of the frequency and complexity of ventricular arrhythmias in never-treated subjects with essential hypertension.