Background: Non-dippers are known to carry a high risk of cardiovascular complications due to higher cumulative 24-h pressure load over time. In this study, we hypothesized that non-dippers would be associated with adverse cardiac remodeling and left ventricular (LV) dysfunction in treated hypertensive patients.
Materials and methods: A total of 150 outpatients treated with antihypertensive drugs for at least 1 year were enrolled. The patients were classified as non-dippers if their daytime ambulatory systolic and diastolic BP did not decrease by at least 10% during the night. LV diastolic function was assessed by measuring mitral inflow velocity (E), early diastolic mitral annulus tissue velocity (E') and LV systolic function was assessed by measuring systolic tissue velocity (S'), longitudinal systolic strain and strain rate.
Results: The Cornell voltage product, LA volume index and LV mass index was significantly higher in non-dippers. Early diastolic mitral annulus tissue velocity (E') was lower and E/E' was higher in non-dippers suggestive of diastolic dysfunction. Systolic tissue velocity (S'), systolic strain and strain rate were significantly lower in non-dippers suggestive of systolic dysfunction. The non-dipper status, controlled for age, sex and LV mass index showed significant correlation with E' (beta=-0.203, P=0.002), E/E' (beta=0.354, P<0.001), S' (beta=-0.231, P=0.002), strain (beta=-0.162, P=0.040) and strain rate (beta=-0.186, P=0.015).
Conclusions: This study showed the non-dippers in treated hypertensive patients were associated with adverse cardiac remodeling and early LV dysfunction. Further studies to demonstrate the long term prognostic significance of this finding is warranted.