Left Ventricular Geometric Patterns of Dippers and Non-Dippers in Essential Hypertension

Background

One of the unique feature of ambulatory blood pressure monitoring is its ability to describe the variations of BP throughout the day and night. Left ventricular hypertrophy and other measures of target organ damage in hypertension are more closely related to the average 24-h BP than to clinic BP. In addition to the mean levels of BP, the characteristics of the 24-h BP profile might be a further determinant of organ in essential hypertension.

Methods

Data were obtrained from 105 patients with essential hypertension and 44 normal subjects. Echocardiography and 24 hour ambulatory blood pressure monitoring were performed in all subjects. At first, relative wall thickness(RWT) and left ventrcular mass index were calculated from normal subject and normal values(RWT<0.44, LV mass index,120gm/m²) were applied to hypertensive patients which were classified to dipper and non-dipper according to the result of ambulatory monitoring.

Results

1) There were 49 dippers and 56 non-dipper in hypertensive patients subjects.

2) Among the dippers, left ventricular mass index and relative wall thickness were normal in 51%, whereas 8.2% had increased relative wall thickness with normal ventricular mass(concentric remodeling), 32.7% had increased mass with normal relative wall thickness(eccentric hypertrophy) and 8.2% had typical hypertensive concentric hypertrophy.

3) Among the non-dippers, left ventriculat mass index and relative wall thicksness were normal in 40%, whereas 41.8% had eccentric hypertophy, 16.4% had concentric hypertrophy, only 1.8% had concentric remodeling.

4) The incidence of concentric hypertophy was significantly increased in non-dipper subjects(15.2%) than dippers(8.2%), especially in non-dipper female patients.

5) The incidence of concentric remodeling was increased in dipper(8.2%), especially in dipper female patients.

6) There were no difference between left ventricular geometies in duration of hypertension, ejecton fracton, fractional shortening, and cardiac index.

7) There were no difference between dipper and non-dipper subjects in total peripheral resistance except dipper female patients(1,484±535 dynes·s·cm⁵).

Conclusion

Patterns of left ventricular hypertophy and geometric remodeling in essential hypertension may not be influenced by the duration of hypertension, but by gender, blood pressure level, diurnal rhythm and total peripheral resistance.