Pulse wave velocity (PWV) is an indicator associated with the arterial stiffness. Although this technique has been used in the diagnosis of systemic arterial hypertension (SAH), it cannot supply alone enough information about the pathogenesis of this disturbance. This paper aims to determine the compliance of brachial-radial arterial segment by applying a three-element windkessel model, and by using the same pressure waveforms acquired to calculate the PWV. The proposed method to determine the arterial compliance was evaluated with a physical simulation of the arterial system, where parameters were known, resulting in an estimation error of 0.73 x 10(-7) cm5 dyne(-1). In a clinical study the estimated compliance was statistically different (p < 0.01) in a controlled group ((3.12 +/- 3.53) x 10(-7) cm5 dyne(-1)) and in an SAH group ((1.04 +/- 0.74) x 10(-7) cm5 dyne(-1)). It was observed that the PWV value calculated using the maximum of the first derivative of the pressure waveform upstroke as characteristic points was the best correlated (r = -0.71) with the determined compliance. Because SAH normally results, among other causes. from a decreased arterial compliance the results suggest that the determined compliance could be used concomitantly with PWV to supply more diagnostic information about the pathogenesis of SAH.

Background Hypertension is a clinical condition that manifests target-organ damage (TOD) with symptoms. This study investigates the association between Zangfu patterns and symptomatic manifestations of TOD. Methods Datasets with manifestations of Zangfu patterns (Liver-fire blazing upwards; Kidney-yin deficiency and Liver-yang rising; obstruction of phlegm and dampness of Heart/Liver/Gallbladder; qi and blood deficiency leading to Liver-yang rising; Kidney-yin/yang deficiency) and TODs (cerebrovascular, heart and kidney) were compiled from literature. The Pattern Differentiation Algorithm was used to test and to determine diagnostic accuracy with these datasets. A questionnaire was developed from datasets and applied to 43 subjects newly diagnosed with hypertension. Pattern differentiation was performed and the results were statistically analyzed for association between descriptions of patterns and TOD. Results The observed diagnostic accuracy, sensitivity and specificity were 98.0%, 96.2% and 99.8% respectively. Similarity between patterns and TOD datasets was mostly negligible. Twelve manifestations demonstrated high prevalence, namely red tongue (81.4%), headache (72.1%), irritability (67.4%), palpitation (60.5%), blurred vision, insomnia and mental fatigue (58.1%), frequent nocturnal urination, numbness in feet and hands, shortness of breath (55.8%), and heavy limbs sensation, wiry pulse (51.2%). No significant association was found between blood pressure variables (systolic, diastolic, mean, pulse pressure) and manifestations. Conclusion Zangfu patterns are associated with clinical manifestations of TOD. Manifestations associated patterns indicate morbid conditions to be secondary to hypertension rather than simple blood pressure.

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This paper proposes a simplified distributed-parameter model of the brachial-radial arteries segment for the determination of mechanical parameters of these arteries and compares it with a four-element Windkessel model. The comparison is performed using data collected noninvasively of pressure pulse waveforms at two different locations of the arterial segment, under physiological (normotensive) and pathological (primary hypertension) conditions. The results show, by Akaike Information Criterion, that the proposed model fits the real pressure pulse waveform better than classical Windkessel model, and that also gives mechanical parameters coherent with the clinical condition.