Heart rate variability (HRV) has emerged as a predictor of later cardiac risk. This study tested whether pregnancy complications that may have long-term offspring cardiac sequelae are associated with differences in HRV at birth, and whether these HRV differences identify abnormal cardiovascular development in the postnatal period. Ninety-eight sleeping neonates had 5-min electrocardiogram recordings at birth. Standard time and frequency domain parameters were calculated and related to cardiovascular measures at birth and 3 months of age. Increasing prematurity, but not maternal hypertension or growth restriction, was associated with decreased HRV at birth, as demonstrated by a lower root mean square of the difference between adjacent NN intervals (rMSSD) and low (LF) and high-frequency power (HF), with decreasing gestational age (p < 0.001, p = 0.009 and p = 0.007, respectively). We also demonstrated a relative imbalance between sympathetic and parasympathetic tone, compared to the term infants. However, differences in autonomic function did not predict cardiovascular measures at either time point. Altered cardiac autonomic function at birth relates to prematurity rather than other pregnancy complications and does not predict cardiovascular developmental patterns during the first 3 months post birth. Long-term studies will be needed to understand the relevance to cardiovascular risk.
Rationale: Microparticles are cell-derived membrane vesicles, relevant to a range of biological responses and known to be elevated in cardiovascular disease. Objective: To investigate microparticle release during cardiac stress and how this response differs in those with vascular disease. Methods and Results: We measured a comprehensive panel of circulating cell-derived microparticles by a standardized flow cytometric protocol in 119 patients referred for stress echocardiography. Procoagulant, platelet, erythrocyte, and endothelial but not leukocyte, granulocyte, or monocyte-derived microparticles were elevated immediately after a standardized dobutamine stress echocardiogram and decreased after 1 hour. Twenty-five patients developed stress-induced wall motion abnormalities suggestive of myocardial ischemia. They had similar baseline microparticle levels to those who did not develop ischemia, but, interestingly, their microparticle levels did not change during stress. Furthermore, no stress-induced increase was observed in those without inducible ischemia but with a history of vascular disease. Fourteen patients subsequently underwent coronary angiography. A microparticle rise during stress echocardiography had occurred only in those with normal coronary arteries. Conclusions: Procoagulant, platelet, erythrocyte, and endothelial microparticles are released during cardiac stress and then clear from the circulation during the next hour. This stress-induced rise seems to be a normal physiological response that is diminished in those with vascular disease.
Acute lymphoblastic leukemia (ALL) is the commonest childhood malignancy in Australian children. Recently published data from Western Australia suggest a link between proportion of optimal birth weight and the risk of ALL, but few studies have investigated the relationship between growth during infancy and early childhood and risk of leukemia. The aim of this study was to determine whether children diagnosed with ALL in Western Australia were taller at the time of diagnosis than children of the same age and sex in the general population.Records of children diagnosed with ALL between January 1984 and June 2008 were accessed. Height before the commencement of chemotherapy was recorded and compared to the height of population norms derived from the Longitudinal Study of Australian Children.On average, male cases were 0.67 cm (95% CI -0.21, 1.54 cm) taller and female cases were 0.30 cm (95% CI -0.68, 1.28 cm) taller than population controls.Our results suggest that children diagnosed with ALL in Western Australia are slightly taller than their counterparts in the general population. These findings are consistent with at least one previous study. While this increase in height may be too small to be recognizable clinically, it is consistent with the notion that growth factors play a role in the pathogenesis of ALL beyond infancy.
Preeclampsia is an independent cardiovascular risk factor for the mother, and recent studies reveal that offspring of affected pregnancies also may have an increased cardiovascular risk. Our objective was to examine evidence for increased cardiovascular risk factors in children exposed to preeclampsia in utero.We performed a systematic review and meta-analysis on studies reporting traditional cardiovascular risk factors in those exposed to preeclampsia compared to controls. Information was extracted on the classic cardiovascular risk factors, including blood pressure, lipid profile, glucose metabolism, and BMI from articles published between 1948 and August 2011 in Medline and Embase.Eighteen studies provided cumulated data on 45,249 individuals. In utero exposure to preeclampsia was associated with a 2.39 mm Hg (95% confidence interval: 1.74-3.05; P < .0001) higher systolic and a 1.35 mm Hg (95% confidence interval: 0.90-1.80; P < .00001) higher diastolic blood pressure during childhood and young adulthood. BMI was increased by 0.62 kg/m2 (P < .00001). Associations were similar in children and adolescents, for different genders, and with variation in birth weight. There was insufficient evidence to identify consistent variation in lipid profile or glucose metabolism.Young offspring of pregnancies complicated by preeclampsia already have increased blood pressure and BMI, a finding that may need to be considered in future primary prevention strategies for cardiovascular disease.
Preterm birth leads to an early switch from fetal to postnatal circulation before completion of left ventricular in utero development. In animal studies, this results in an adversely remodeled left ventricle. We determined whether preterm birth is associated with a distinct left ventricular structure and function in humans. A total of 234 individuals 20 to 39 years of age underwent cardiovascular magnetic resonance. One hundred two had been followed prospectively since preterm birth (gestational age=30.3±2.5 week; birth weight=1.3±0.3 kg), and 132 were born at term to uncomplicated pregnancies. Longitudinal and short-axis cine images were used to quantify left ventricular mass, 3-dimensional geometric variation by creation of a unique computational cardiac atlas, and myocardial function. We then determined whether perinatal factors modify these left ventricular parameters. Individuals born preterm had increased left ventricular mass (66.5±10.9 versus 55.4±11.4 g/m(2); P<0.001) with greater prematurity associated with greater mass (r = -0.22, P=0.03). Preterm-born individuals had short left ventricles with small internal diameters and a displaced apex. Ejection fraction was preserved (P>0.99), but both longitudinal systolic (peak strain, strain rate, and velocity, P<0.001) and diastolic (peak strain rate and velocity, P<0.001) function and rotational (apical and basal peak systolic rotation rate, P =0.05 and P =0.006; net twist angle, P=0.02) movement were significantly reduced. A diagnosis of preeclampsia during the pregnancy was associated with further reductions in longitudinal peak systolic strain in the offspring (P=0.02, n=29). Individuals born preterm have increased left ventricular mass in adult life. Furthermore, they exhibit a unique 3-dimensional left ventricular geometry and significant reductions in systolic and diastolic functional parameters. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01487824.
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