Brachial artery diameter and the right ventricle: the Multi-Ethnic Study of Atherosclerosis-right ventricle study

Correlation analysis of human upper arm parameters to oscillometric signal in automatic blood pressure measurement

Cardiovascular diseases are the leading cause of global deaths, making cardiovascular health monitoring important. Measuring blood pressure using an automatic sphygmomanometer is the most widely used method to monitor cardiovascular health due to its accessibility, convenience, and strong correlation with cardiovascular diseases. In this work, in order to estimate brachial artery diameter, stiffness, or thickness using an automatic sphygmomanometer, the correlation between upper arm parameters and the oscillometric signal was intensively investigated through analytical, numerical, and experimental approaches. The parametric studies commonly revealed that the inner radius of the brachial artery is the most influential parameter in determining the amplitude of the oscillometric signal. The experimental results of using a cardiovascular simulator (a virtual patient) combined with upper arm phantoms with various inner radii of the brachial artery showed a 6.5% change in the oscillometric signal amplitude with a 10% artery radius variation. It was concluded that the oscillometric signal can be used to evaluate brachial artery diameter. Based on the clinical relationship between brachial artery diameter and cardiovascular risk factors such as hypertension, diabetes, and obesity, this study showed and verified a novel method to monitor brachial artery diameter and hence, cardiovascular risks while measuring blood pressure.

Pathophysiology of Hypertensive Heart Disease: Beyond Left Ventricular Hypertrophy

PURPOSE OF REVIEW

Given that the life expectancy and the burden of hypertension are projected to increase over the next decade, hypertensive heart disease (HHD) may be expected to play an even more central role in the pathophysiology of cardiovascular disease (CVD). A broader understanding of the features and underlying mechanisms that constitute HHD therefore is of paramount importance.

RECENT FINDINGS

HHD is a condition that arises as a result of elevated blood pressure and constitutes a key underlying mechanism for cardiovascular morbidity and mortality. Historically, studies investigating HHD have primarily focused on left ventricular (LV) hypertrophy (LVH), but it is increasingly apparent that HHD encompasses a range of target-organ damage beyond LVH, including other cardiovascular structural and functional adaptations that may occur separately or concomitantly. HHD is characterized by micro- and macroscopic myocardial alterations, structural phenotypic adaptations, and functional changes that include cardiac fibrosis, and the remodeling of the atria and ventricles and the arterial system. In this review, we summarize the structural and functional alterations in the cardiac and vascular system that constitute HHD and underscore their underlying pathophysiology.

Endogenous Sex Hormones and Endothelial Function in Postmenopausal Women and Men: The Multi-Ethnic Study of Atherosclerosis

Background: The relationship of endogenous sex hormones (SH) with vascular endothelial function and with cardiovascular disease (CVD) is incompletely understood. We examined the associations between SH and endothelial function measured by brachial artery flow-mediated dilation (FMD). Materials and Methods: We included 1368 postmenopausal women and 1707 men, free of clinical CVD, participating in MESA Visit 1 (2000-2002). Serum SH [total testosterone, SH binding globulin (SHBG), dehydroepiandrosterone (DHEA), estradiol] were measured; free testosterone was calculated. The percent FMD difference (%FMD) was measured by high-resolution ultrasound. Using multivariable-adjusted linear regression, we tested the cross-sectional associations of SH (log transformed, compared per one SD increment) with %FMD. Results: The mean age of women and men were 64.2 and 61.4 years, respectively. Among women, after adjusting for demographics, CVD risk factors, and hormone therapy, higher SHBG was associated with greater %FMD [β = 0.215% (95% CI 0.026-0.405)], whereas higher free testosterone was associated with a smaller %FMD [-0.209% (-0.402, -0.017)]. Estradiol and DHEA were not associated with %FMD in women after multivariable adjustment. There was an age interaction, with higher free testosterone and lower SHBG associated with worse FMD in women <65 years of age, but not in those ≥65 years (p = 0.04). We did not see similar associations in men. Conclusions: A more androgenic SH profile of higher free testosterone and lower SHBG was associated with worse %FMD in postmenopausal women. Changes in SH with aging and menopause may result in vascular changes in women. Further studies are needed to assess longitudinal changes in SH levels and their association with vascular function.

Retinal vascular changes and right ventricular structure and function: the MESA-Right Ventricle and MESA-Eye studies

Retinal vessel diameters have been associated with left ventricular morphology and function but their relationship with the right ventricle (RV) has not been studied. We hypothesized that wider retinal venules and narrower retinal arterioles are associated with RV morphology and function. RV end-diastolic mass (RVEDM), end-diastolic volume (RVEDV), end-systolic volume (RVESV), stroke volume (RVSV), and ejection fraction (RVEF) were assessed using cardiac magnetic resonance imaging (MRI) scans of 4204 participants without clinical cardiovascular disease at the baseline examination; retinal photography was obtained at the second examination. Mean diameters of retinal arterioles and venules were measured and summarized as central retinal vein and artery equivalents (“veins” and “arteries,” respectively). After adjusting for covariates, wider veins were associated with greater RVEDM and RVEDV in women (P = 0.04 and P = 0.02, respectively), whereas there was an inverse association with RVEDV in men (P = 0.02). In both sexes, narrower arteries were associated with lower RVEDM (P < 0.001 in women and P = 0.002 in men) and smaller RVEDV (P < 0.001 in women and P = 0.04 in men) in adjusted models. Narrower arteries were also associated with lower RVEF in men but this was of borderline significance after adjusting for the LVEF (P = 0.08). Wider retinal venular diameter was associated with sex-specific changes in RVEDM and RVEDV in adults without clinical cardiovascular disease. Narrower retinal arteriolar diameter was associated with significantly lower RVEDM and smaller RVEDV in both sexes.

Respiratory and limb muscle dysfunction in pulmonary arterial hypertension: a role for exercise training?

Respiratory and limb muscle dysfunction is emerging as an important pathophysiological abnormality in pulmonary arterial hypertension (PAH). Muscle abnormalities appear to occur frequently and promote dyspnea, fatigue, and exercise limitation in patients with PAH. Preliminary data suggest that targeted muscle training may be of benefit, although further evidence is required to consolidate these findings into specific recommendations for exercise training in patients with PAH. This article reviews the current evidence on prevalence, risk factors, and implications of respiratory and limb muscle dysfunction in patients with PAH. It also reviews the impact of exercise rehabilitation on morphologic, metabolic, and functional muscle profile and outcomes in PAH. Future research priorities are highlighted.

The association of brachial artery diameter with noncalcified coronary plaque burden in apparently healthy individuals

OBJECTIVE

Coronary atherosclerosis has been associated with systemic arterial remodeling even in nonatherosclerotic vessels. However, it is not known whether systemic remodeling is differentially associated with the cumulative atherosclerotic process, reflected by putatively quiescent calcified plaque (CP), or with active atherosclerosis, consisting of noncalcified plaque (NCP). We thus examined the association of brachial artery diameter (BAD), an artery that does not suffer clinical atherosclerosis, with the presence and the extent of coronary CP and NCP.

METHODS

We studied 688 apparently healthy, asymptomatic participants from 350 families with a history of early-onset coronary artery disease (<60 years of age) by measuring coronary artery disease risk factors and coronary plaque using dual-source computed tomographic angiography. Plaque volumes were quantified using a validated automated method. BAD was measured during diastole using B-mode ultrasound. The association of resting BAD with any detectable plaque, and log-transformed CP and NCP volumes if detectable, was tested using generalized estimating equations adjusted for age, sex, race, current smoking, diabetes, hypertension, BMI, and non-HDL and HDL cholesterol.

RESULTS

Higher quintiles of BAD were associated with greater age and male sex (both P<0.001). In the fully adjusted analysis, CP volume was not associated with BAD (P=0.65) but a 1 ml greater NCP volume was associated with a 0.65 mm larger BAD (P=0.027).

CONCLUSION

Our results suggest that systemic arterial remodeling of nonatherosclerotic arteries is a dynamic process that is correlated with the extent of putatively active atherosclerotic processes in distant beds but not with inactive accumulated plaque burden.