ABSTRACT
BACKGROUND: Endothelial dysfunction is associated with left ventricular morphology and long-term cardiovascular outcomes. The purpose of this study was to assess the relationship between both baseline brachial artery diameter and peripheral endothelial function (assessed by brachial artery ultrasonography) and right ventricular (RV) mass, RV end-diastolic volume (RVEDV), and RV ejection fraction (RVEF). METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac MRI and brachial artery ultrasonography on participants without clinical cardiovascular disease. Baseline brachial artery diameter and flow-mediated dilation were assessed. RESULTS: The mean age was 60.9 years, and 49.4% of subjects were men (n = 2,425). In adjusted models, larger brachial artery diameter was strongly associated with greater RV mass (ß = 0.55 g, P < .001), larger RVEDV (ß = 3.99 mL, P < .001), and decreased RVEF (ß = -0.46%, P = .03). These relationships persisted after further adjustment for the respective left ventricular parameters. Flow-mediated dilation was not associated with RV mass or RVEF and was only weakly associated with RVEDV. CONCLUSIONS: Brachial artery diameter is associated with greater RV mass and RVEDV, as well as lower RVEF. Changes in the systemic arterial circulation may have pathophysiologic links to pulmonary vascular dysfunction or abnormalities in RV perfusion.
Subject(s)
Atherosclerosis/ethnology , Atherosclerosis/pathology , Brachial Artery/pathology , Brachial Artery/physiopathology , Heart Ventricles/pathology , Heart Ventricles/physiopathology , Aged , Aged, 80 and over , Asian People , Atherosclerosis/physiopathology , Black People , Brachial Artery/diagnostic imaging , Cohort Studies , Diastole/physiology , Endothelium, Vascular/diagnostic imaging , Endothelium, Vascular/pathology , Endothelium, Vascular/physiopathology , Female , Heart Ventricles/diagnostic imaging , Hispanic or Latino , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Prospective Studies , Stroke Volume/physiology , Ultrasonography, Interventional , White PeopleABSTRACT
BACKGROUND: Dysfunction of the interventricular septum has been implicated in right ventricular (RV) failure. However, little is known about the relationship between ventricular septal and RV function in patients without clinical cardiovascular disease. We hypothesized that better septal function would be associated with higher RV ejection fraction and lower RV mass and volume by cardiac MRI. METHODS: In the Multi-Ethnic Study of Atherosclerosis (MESA), cardiac MRI was performed on community-based participants without clinical cardiovascular disease. Images were analyzed by the harmonic phase method to measure peak circumferential systolic midventricular strain for each wall (anterior, lateral, inferior, and septal). Multivariable linear regression and generalized additive models were used to assess the relationship between septal strain and RV morphology. RESULTS: There were 917 participants (45.7% women) with a mean age of 65.7 years. Better septal function was associated with higher RV ejection fraction in a nonlinear fashion after adjustment for all covariates (P = .03). There appeared to be a threshold effect for the contribution of septal strain to RV systolic function, with an almost linear decrement in RV ejection fraction with septal strain from -18% to -10%. Septal function was not related to RV mass or volume. CONCLUSIONS: Interventricular septal function was linked to RV systolic function independent of other left ventricular regions, even in individuals without clinical cardiovascular disease. This finding confirms animal and human research suggesting the importance of septal function to the right ventricle and implies that changes in septal function could herald RV dysfunction. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00005487; URL: www.clinicaltrials.gov.
Subject(s)
Asian , Black or African American , Heart Septum/physiopathology , Hispanic or Latino , Ventricular Dysfunction, Right/physiopathology , White People , Aged , Aged, 80 and over , Atherosclerosis/ethnology , Atherosclerosis/physiopathology , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Stroke Volume , Systole , Ventricular Dysfunction, Right/ethnology , Ventricular Function, LeftABSTRACT
Rimonabant is a selective blocker of the CB(1) cannabinoid receptor that has been developed for treatment of abdominal obesity, dyslipidemia, and control of diabetes. Four randomized clinical trials have demonstrated that following 1 year of treatment, 20 mg/d of rimonabant is associated with greater weight loss and reduction in waist circumference compared with placebo. Therapy with rimonabant is associated with favorable changes in serum high-density lipoprotein and triglycerides, as well as with an improvement in glycemic control among obese type 2 diabetic patients. Rimonabant appears to be well tolerated, with the most common side effects being nausea, anxiety, and depressive symptoms. Rimonabant is a novel agent that has the potential to be a useful adjunct to lifestyle and behavior modification in treatment of abdominal obesity, dyslipidemia, and dysglycemia.
