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Introduction: The effect of mitochondrial DNA copy number (mtDNA-CN), which reflects energy reserves and oxidative stress, on left ventricular (LV) remodeling in the general population may provide insights into heart failure development. Hypothesis: Lower mtDNA-CN values from blood samples will be associated with concentric remodeling. Methods: Longitudinal analyses of MESA participants with mtDNA-CN and MRI-measured LV mass to volume ratio (MVR) at baseline and the 10-year follow-up (n=2735) were performed. mtDNA-CN was estimated using 25 high-quality mitochondrial single nucleotide polymorphisms from the Affymetrix 6.0 array. Analyses were adjusted for age, sex, and field center, and standardized. LV mass and volumes were measured from cine images. Concentric remodeling was assessed by higher MVR. The association of mtDNA-CN with MVR, adjusted for the ASCVD/AHA risk score as a time-varying covariate, was assessed with mixed-effects models. Longitudinal change in MVR and LV ejection fraction (LVEF) was assessed with an interaction term of mtDNA-CN and time. Results: Population average age (SD) was 60 (9) years, with 48% males, 42% Caucasians, 12% Chinese, 22% African-American and 21% Hispanics. Mean MVR was 0.95 (0.18) g/ml at baseline and 1.05 (0.23) g/ml at follow-up. Lower mtDNA-CN was associated with higher MVR values (coef=-0.006, p=0.01, Fig 1), as well as greater longitudinal change in slope of this association (interaction term coef =-0.008, p=0.03) with small effect sizes (Cohens f2= -0.018 and -0.019 respectively). The longitudinal change reflected greater increase in concentric remodeling in those with low mtDNA-CN at baseline. mtDNA-CN values were not associated with LVEF. Conclusions: Lower mtDNA-CN was associated with both high levels at baseline and longitudinally increasing levels of concentric remodeling in a multiethnic population free of CVD at baseline. Altered myocardial energy reserves may contribute to concentric remodeling

The development of joint attention skills is considered to be critical to early social, cognitive and language development. Joint attention skills refer to the capacity to coordinate attention with others regarding objects and events. While infants and toddlers display systematic, age related gains in joint attention skill development between 6 and 18 months of age, they also may display considerable individual differences in the development of this skill. Little research, however, has been directed toward evaluating the significance of these individual differences. This longitudinal study of 14- to 17-month-olds was designed to examine the hypothesis that individual differences in one type of joint attention skill, the tendency to follow the gaze and pointing of a tester, would be a significant predictor of receptive language development. The second goal of this study was to examine the assumption that different types of joint attention skill reflect the development of a single common cognitive process. The results provided strong support for the primary hypothesis, but equivocal support for the common process assumption. In particular, the results of this study suggested that different types of joint attention skills may reflect partially distinct processes associated with comprehension and expression factors in early social-communication development. The results of this study have implications for current conceptualizations of joint attention development, as well as for understanding the linkage between joint attention and early language development.

This study sought to determine whether increased carotid intima-media thickness (IMT) is related to reduced regional myocardial function in participants of the Multi-Ethnic Study of Atherosclerosis (MESA).Carotid artery IMT is an established index of subclinical atherosclerosis, and tagged magnetic resonance imaging (MRI) can detect incipient alterations of segmental function that precede overt myocardial failure.The MESA study is a prospective observational study including four ethnic groups free from clinical cardiovascular disease. Peak midwall systolic circumferential strain (ECC) and regional strain rates were calculated by harmonic phase from tagged MRI data of 500 participants. Systolic ECC and diastolic strain rate were regressed on IMT of the common carotid artery defined by ultrasound, with adjustments for body mass index, blood pressure, cholesterol, diabetes, smoking, left ventricular hypertrophy, C-reactive protein, age, and gender.The mean participant age was 66 +/- 10 years (mean +/- SD). Among the 58 participants, 4% were male and the interquartile (25th to 75th percentile) range for IMT was 0.25 mm. Multiple linear regression analyses showed that increased IMT was related to reduced systolic regional function (less shortening ECC) in all myocardial regions (p0.05), except in the inferior wall. The analyses also showed that greater IMT was associated with a lower diastolic strain rate (diastolic reduced function) in all regions (p0.01), except in the anterior wall.Greater carotid IMT is associated with alterations of myocardial strain parameters reflecting reduced systolic and diastolic myocardial function. These observations indicate a relationship between subclinical atherosclerosis and incipient myocardial dysfunction in a population free of clinical heart disease.

This study examined the importance of target location (within vs. outside the visual field) on the relation between responding to joint attention and subsequent language development in 47 normally ...

We report two patients with Turner syndrome who had aortic dissection and rupture, one with prior repair of coarctation. We also note the high incidence (8.8%) of unrecognized aortic root dilation in a group of 57 patients with Turner syndrome whom we prospectively evaluated by echocardiography. Our analysis and review of previously reported cases suggests that multiple risk factors may exist for aortic dissection, including coarctation, bicuspid aortic valve, and systemic hypertension, but that these need not be present. Aortic root dilation may be an additional finding that suggests the patient with Turner syndrome is also at risk. When it is present, magnetic resonance imaging visualizes the entire aorta and allows quantification of the site and degree of dilation. In patients with dissection, the aorta often exhibits pathologic evidence of cystic medial necrosis similar to the finding in patients with Marfan syndrome. Therapeutic methods to decrease risk, such as those directed toward prevention of bacterial endocarditis, blood pressure control, and perhaps prophylactic beta blockade or surgical reconstruction, may need to be considered. Patients with Turner syndrome, their families, and the physicians who care for them should be aware of the significance of unexplained chest pain, dyspnea, or hypotension as potential manifestations of aortic dissection or rupture.