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OBJECTIVE: To determine the role of ascending aorta dilatation in the relationship between pulse pressure (PP) and left ventricular (LV) hypertrophy. METHODS: A total of 1556 Chinese elderly hypertensive patients were retrospectively studied. Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements. In addition, brachial blood pressure was measured, and total arterial compliance, systemic vascular resistance, arterial elastance, and end-systolic LV elastance were calculated. The participants were divided into four groups according to the status of ascending aortic diameter and PP. RESULTS: LV mass index increased in succession in the four groups, i.e., the group with the normal aorta and lower PP, with the normal aorta and higher PP, with aortic dilatation and lower PP, and with aortic dilatation and higher PP (P(trend) < 0.001). Total arterial compliance(−1), arterial elastance, and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation, regardless of PP being lower or higher (P < 0.01). Compared to the group with the normal aorta and lower PP, individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy, and higher PP further exacerbated this risk [aortic dilatation with lower PP (OR = 1.75, 95% CI: 1.01–3.04) and aortic dilatation with higher PP (OR = 3.42, 95% CI: 2.03–5.77)]. In the relation between PP and LV mass index (β = 0.095, P < 0.001), -41.3% of the total effect was attributable to mediation by ascending aortic diameter (P < 0.0001). CONCLUSIONS: In Chinese elderly patients with hypertension, ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy.

The design solution presented in this article is a pressure data acquisition system which is based on the piezoresistive pressure sensor and MSP430F249 microcontroller. It can be simulated on the Protues7. FlexiForce-A201 sensor can be seen as a variable resistance in the circuit. Using the signal conditioning circuit and on chip components ADC12 and DAC12 to realize the 8 channels of analog signals and transformation and the A/D conversion accuracy is 12-bit. The results of transformation can be both stored in the M45PE16 flash and real-time displayed on the LCD1602. This system used the on-chip peripherals and powered by button cell. This solution can realize the independence of system and data source by joining up various sensors. It is simple, low-power and universal.