Tiago Gemignani

Postural Changes May Influence Popliteal Atherosclerosis by Modifying Local Circumferential Wall Tension

Atherosclerosis of peripheral arteries typically affects vessels of the lower limbs, suggesting that local hemodynamic stimuli play a role in this process. Our study evaluated the effects of body postural changes on carotid and popliteal blood pressure, circumferential wall tension (CWT) and arterial strain, and investigated the relationship between such hemodynamic parameters and intima-media thickness (IMT) of these arteries. One hundred seventeen nondiabetic, nonhypertensive, nonsmoker subjects (48 men and 69 women) were enrolled and had their blood pressure measured in the arm and calf in supine and orthostatic positions. Echo-doppler analysis evaluated the common carotid and popliteal arteries after blood pressure measurements, while CWT was calculated according to Laplaces law. The results showed that changing from supine to orthostatic posture increased blood pressure and CWT in popliteal but not in carotid arteries. Partial correlation analysis adjusted for age and body mass index revealed no major relationship between IMT of the studied vessels and local blood pressure or arterial strain. Conversely, supine and orthostatic CWT exhibited comparable correlation coefficients with carotid IMT, while orthostatic CWT displayed a stronger relationship with popliteal IMT than with supine CWT. These results were confirmed by multiple linear regression analysis that included age, sex, body mass index, lipid fractions and glucose as independent variables. Overall, our results indicate that orthostatic CWT is a stronger hemodynamic predictor of popliteal IMT than supine CWT, suggesting that erectile posture may be a potential risk factor for popliteal atherosclerosis because it increases the local hemodynamic burden.

Leg blood pressure measured in orthostatic posture is associated with left ventricular mass in normotensive subjects.

BACKGROUND Changing from a supine to an orthostatic posture is associated with substantial increments in leg blood pressure (BP) levels, which could ultimately influence the hemodynamic burden imposed on the heart. This study investigated the relationship between brachial and leg BP measurements and the left cardiac chambers structure and assessed the role of body posture changes in this regard. METHODS One hundred and thirty normotensive, nondiabetic, nonsmoking, normolipemic subjects were evaluated by a clinical history, anthropometry, the analysis of metabolic parameters, echocardiography, and the measurement of BP in the arm and the calf in both supine and orthostatic positions. RESULTS Significant correlation coefficients between the leg BP measurements and the cardiac structure were detected, especially between the orthostatic pulse pressure (PP) and the left ventricular (LV) wall thickness (r = 0.38; P < 0.001), the orthostatic PP and the LV mass (r = 0.37; P < 0.001), and the orthostatic systolic BP (SBP) and the left atrial size (r = 0.35; P < 0.001). Stepwise and standard regression analysis adjusted for brachial BP and anthropometric and metabolic variables confirmed that the leg orthostatic PP was independently related to the LV wall thickness and mass. Moreover, the leg orthostatic SBP was associated with the left atrial dimension even after adding the LV mass to the statistical models. Finally, triglyceride levels and body surface area showed significant relationship with leg orthostatic PP and SBP, whereas brachial orthostatic PP and SBP were only associated with age and anthropometric variables. CONCLUSIONS Orthostatic leg BP is independently associated with the cardiac structure in normotensive subjects.

Quality of life, dyspnea and ventricular function in patients with hypertension

AIM This paper is a report of an investigation of the relationship between health-related quality of life and left ventricular function among patients with hypertension who did not fulfil the criteria for heart failure. BACKGROUND Heart failure is a common consequence of hypertension, with Doppler echocardiography being the gold-standard tool to evaluate left ventricular function, mainly hypertension-induced left ventricular damage. Echocardiographic data indicating poorer ventricular function have been related to lower levels of health-related quality of life in patients with systolic and/or diastolic heart failure. However, data are still lacking regarding the correlation between health-related quality of life and left ventricular function and structure in patients with hypertension who do not fulfil the criteria for heart failure. METHOD Between September 2005 and February 2007, 98 patients with hypertension without systolic or diastolic heart failure were evaluated. Health-related quality of life was assessed using the Medical Outcomes Study Short Form-36. Left ventricular function was evaluated through Tissue Doppler echocardiography. RESULTS Statistically significant but weak correlations (varying from r = -0.22 to 0.35) were observed between some of the Short Form-36 domains and echo data. To consider the potential effect of dyspnoea in this relationship, patients were split according to the presence or absence of the symptom. In the subgroup without dyspnoea, similar patterns of correlation were observed (varying from r = 0.26 to 0.32). In the subgroup with dyspnoea, however, more and stronger correlations were observed between echo data and health-related quality of life domains, varying from r = -0.40 to 0.50. CONCLUSION Nurses should be aware of the relevance of evaluating the functional echocardiographic data of patients who not fulfil heart failure criteria, but who experience dyspnoea in order to implement appropriate action plans.

Increased popliteal circumferential wall tension induced by orthostatic body posture is associated with local atherosclerotic plaques

OBJECTIVE Lower limb arteries are exposed to higher hemodynamic burden in erectile posture. This study evaluated the effects of body posture on popliteal, carotid and brachial circumferential wall tension (CWT) and investigated the relationship between local CWT and atherosclerotic plaques in subjects with cardiovascular risk factors. METHODS Two hundred and three subjects (118 women and 85 men) with cardiovascular risk factors (smoking, hypertension or diabetes mellitus) underwent clinical and laboratory analysis and had their blood pressure measured in the arm and calf in supine and orthostatic positions. Arteries were evaluated by ultrasound analysis, while CWT was calculated according to Laplaces law. RESULTS Among the enrolled participants, 47%, 29% and none presented popliteal, carotid and brachial plaques, respectively. Carotid CWT measurements were not associated with local plaques after adjustment for potential confounders. Conversely, general linear model and logistic regression analyses adjusted for potential confounders demonstrated that peak orthostatic CWT was the only local hemodynamic parameter showing significant relationship with popliteal plaques in the whole sample. In gender-specific analyses, although positively correlated with popliteal plaques in both genders, local peak orthostatic CWT exhibited an independent association with popliteal plaques after adjustment for potential confounders only in women. CONCLUSION Popliteal CWT measured in orthostatic posture, rather than in supine position, is associated with popliteal atherosclerotic plaques, particularly in women. These findings suggest that erectile posture might play a role in the atherogenesis of leg arteries by modifying local hemodynamic forces and that there may be gender differences in this regard.