Cardiac Arrhythmias and Left Ventricular Hypertrophy in Dipper and Nondipper Patients With Essential Hypertension

Abstract

To evaluate the behavior of cardiac arrhythmias in dipper and nondipper hypertensive patients, 48-h ambulatory blood pressure monitoring, 24-h Holter electrocardiogram recording and echocardiographic studies were performed in 56 untreated outpatients with essential hypertension. These patients were divided into 2 groups according to the presence (dipper, n=33) or absence (nondipper, n=23) of reduction of both systolic and diastolic blood pressure during nighttime by an aerage of more than 10% of daytime blood pressure. Mean 48-h systolic and diastolic blood pressures did not differ between the 2 groups. Nondipper patients had a significantly larger left atrial dimension (31.9±3.8 vs 35.6±3.7mm; p<0.01), left ventricular mass index (114±26 vs 136±36g/m²; p<0.05), as well as a larger number of total supraventricular (16±19 vs 89±197 beats; p<0.05) and ventricular ectopic beats (7±14 vs 47±96 beats; p<0.05) during daytime as compared with dippers. In conclusion, nondipper hypertensive patients are likely to experience supraventricular and ventricular arrhythmias more frequently than dippers. A blunted nocturnal blood pressure fall may be involved in the appearance of cardiac arrhythmias in patients with essential hypertension.