Body surface area as a key determinant of aortic root and arch dimensions in a population-based study.

The associations between the aortic dimensions (of the aortic sinus, aortic annulus and aortic arch) and physiological variables have not been established in the Chinese population. The present study examined the associations among physiological variables to determine the aortic root and arch dimensions echocardiographically. The diameters of the aortic sinus, annulus and arch were measured in 1,010 subjects via 2-D echocardiography with a 3.5-MHz transducer in a trans-thoracic position. The images of the aortic sinus and aortic annulus were obtained from a standard parasternal long-axis view. The maximum diameter of the valve orifice was measured at the end of systole. The aortic arch dimension was visualized in the long-axis using a suprasternal notch window and the maximum transverse diameter was measured. Epidata 3.0, Excel 2007 and SPSS version 17.0 were used to collect and analyze the data. A total of 1,010 subjects were enrolled. The mean age was 55.0±17.0 years (range of 18 to 90 years). The body surface area (BSA) was the best predictor of all the studied physiological variables and may be used to predict aortic sinus, annulus and arch dimensions independently (r=0.54, 0.37 and 0.39, respectively). Gender, blood pressure, age and BSA are significant predictors of the aortic dimensions. Of these, BSA was the best predictor.

Association between the rate of the morning surge in blood pressure and cardiovascular events and stroke.

BACKGROUND: The exaggerated surge in morning blood pressure (BP) that many patients experience upon awakening may be closely related to target organ damage and may be a predictor of cardiovascular complications. However, no previous studies have evaluated the rate of this surge independently of the evening period. It remains unclear whether the rate of increase experienced during the surge is a significant or independent determinant of cardiovascular events. METHODS: We randomly selected 340 ambulatory BP monitoring (ABPM) patients. All subjects without type 2 diabetes mellitus were divided into two groups: hypertensive group (n = 170) and normotensive group (n = 170). We analyzed ambulatory blood pressure recordings using a double logistic curve-fitting procedure to determine whether the magnitude of the surge in BP and heart rate (HR) in the morning is related to the level of BP in hypertensive individuals. We evaluated the association between the rate of the morning surge in systolic BP (SBP) and the incidence of myocardial infarction and stroke in normotensive and hypertensive subjects. RESULTS: Comparisons between hypertensive and normotensive subjects showed that the rates of the morning surges in SBP, mean BP (MBP), and diastolic BP (DBP) were greater in the hypertensive group (P < 0.05) than in the normotensive group. The rate of morning surge in BP was found to be correlated with the daytime SBP (r = 0.236, P < 0.01), the difference between the day and night plateau (r = 0.249, P < 0.01), and the night SBP (r = -0.160, P < 0.05), respectively. After controlling for age, sex, and mean systolic pressure within 24 hours (24 h SBP), the rate of morning surge in SBP was closely correlated with daytime SBP (r = 0.463, P < 0.001), night SBP (r = -0.173, P < 0.05), and the difference between the day and night plateau (r = 0.267, P < 0.001). Logistic regression analysis revealed that the rate of morning surge in SBP was an independent determinant of myocardial infarction (OR = 1.266, 95% CI = 1.153 - 1.389, P < 0.001) and stroke (OR = 1.367, 95% CI = 1.174 - 1.591, P < 0.001). CONCLUSIONS: The rate of the morning surge in BP is greater in hypertensive subjects than in normotensive subjects. Daytime SBP may be the best predictor of the rate of morning surge in SBP. The rate of the morning surge in BP is associated with cardiovascular and stroke events.