Acute cardiovascular responses in preterm infants at 34–39 weeks of gestational age

Background

Premature infants demonstrate immature physiological control mechanisms; however their acute cardiovascular control has not yet been widely studied.

Aim

The aim of this study was to analyze heart rate (HR) and blood pressure (BP) control in preterm infants.

Subjects

Twenty preterm infants with a mean gestational age of 31 ± 2.4 (26–34) weeks at birth were evaluated at a gestational age of 36 ± 1.5 (34–39) weeks. Results were compared to twenty, healthy, full-term, control infants studied at the age of 12 ± 3 weeks.

Outcome measures

HR and BP responses to 45° head-up tilt and side motion tests during non-rapid eye movement sleep were analyzed. In addition, HR responses to spontaneous arousals from non-rapid eye movement sleep were evaluated.

Results

Preterm infants showed significantly smaller initial HR and BP responses compared with controls in head-up tilt (HR p = 0.0005, systolic BP p = 0.02, diastolic BP p = 0.01) and side motion tests (HR p = 0.002, systolic BP p < 0.0001, diastolic BP p < 0.0001). Furthermore, in tilt tests, preterm infants presented with greater intersubject variability in BP responses than controls (systolic BP p = 0.009, diastolic BP p = 0005). Preterm HR responses to spontaneous arousals were similar to controls.

Conclusions

This study indicates immature vestibulo-mediated cardiovascular control in preterm infants compared with term infants. This is seen as attenuated BP responses to side motion test and more labile acute BP control to postural challenge.     

苯磺酸氨氯地平联合氯沙坦治疗原发性高血压的疗效观察

目的评价苯磺酸氨氯地平联合氯沙坦治疗原发性高血压的临床疗效。方法对照组予氯沙坦50 mg/次,1次/d,口服;观察组同时联合苯磺酸氨氯地平5 mg/次,每天1次,口服。两组均连续治疗4周。治疗后对比分析两组的疗效及血压变化情况。结果治疗后,研究组和对照组的SBP、DBP血压水平分别明显低于治疗前,且研究组患者治疗的SBP、DBP水平分别明显低于对照组,组间两两比较,差异无统计学意义(P0.05),治疗后,研究组总有效率98.00%,对照组总有效率70.00%,研究组的总有效率明显高于对照组,差异有统计学意义(P0.05),治疗后,研究组和对照组的SBP、DBP血压水平分别明显低于治疗前,且研究组患者治疗的SBP、DBP水平分别明显低于对照组,组间两两比较,差异有统计学意义(P0.05),治疗后,研究组总有效率98.00%,对照组总有效率70.00%,研究组的总有效率明显高于对照组,差异有统计学意义(P0.05)。结论苯磺酸氨氯地平联合氯沙坦治疗原发性高血压效果确切,值得临床广泛推广和应用。     

Correlation between clinic,cumulative, 24h-ambulatory systolic blood pressure,and chronic kidney damage in Chinese elderly

The aim of this study was to investigate whether clinic, cumulative, and 24h ambulatory systolic blood pressure (SBP) was associated with chronic kidney damage, de?nd as estimated glomerular filtration rate (eGFR) <60 ml/(min·1.73 m2) and/or microalbuminuria ≥30 mg/L, and, if so, which measurement of SBP is more associated with chronic kidney damage in Chinese elderly. A total of 1207 participants older than 60 years old were included in the final analysis. Clinical blood pressure, cumulative blood pressure exposure was calculated and ambulatory 24h blood pressure was assessed. Multiple logistic regression analysis showed that the clinic (p < .001), cumulative (p = .033), 24h average (p < .001), daytime (p = .001) and nighttime SBP (p = .001) were respectively associated with lower eGFR, and cumulative (p = .008), 24 average (p < .001), daytime (p < .001), and nighttime SBP (p < .001) were the risk factors of microalbuminuria. The degree of correlation were strongest between 24h average SBP and chronic kidney damage (odds ratio, 1.78; 95% confidence interval, 1.46–2.15; p < .001), clinic SBP and eGFR (odds ratio, 1.57; 95% confidence interval, 1.13–2.17; p = .007), nighttime SBP and microalbuminuria (odds ratio, 1.45; 95% confidence interval, 1.05–2.00; p = .024). The likelihood ratio test demonstrated that the introduction of 24h average SBP will improve the goodness of fit of the clinic SBP model(p < .05), while the introduction of cumulative SBP exposure has no such effect(p > .05). Cumulative SBP exposure seems inferior to other measurement in indentifying chronic kidney damage, including decreased GFR and microalbuminuria.     

The effect of sleep duration and sleep quality on hypertension in middle-aged and older Chinese: the Dongfeng-Tongji Cohort Study

ObjectiveTo examine the independent and combined associations of sleep duration and sleep quality with hypertension in a middle-aged and older Chinese population.MethodsWe included 21,912 individuals aged 62.2 years at baseline from September 2008 to June 2010, and they were followed until October 2013. Sleep duration was self-reported and sleep quality was evaluated with questions designed according to the Pittsburgh Sleep Quality Index. Hypertension was defined as blood pressure ≥140/90 mmHg, or self-reported physician diagnosis of hypertension, or self-reported current use of antihypertensive medication.ResultsIn the cross-sectional analyses, the odds ratio of hypertension prevalence was significantly elevated (OR = 1.13, 95% CI = 1.03–1.24) in those who slept less than 7 h after adjusting for sex, age, body mass index, midday napping, cigarette smoking and sleep quality. It was particularly evident among males (OR = 1.19, 95% CI = 1.01–1.40) and individuals who were thin (OR = 2.00, 95% CI = 1.01–3.93) with full adjustment. The association was also found for sleep duration of 9∼<10 h after adjusting various covariates (OR = 1.14, 95% CI = 1.04–1.27). In addition, impaired sleep quality was only associated with hypertension in obese individuals (OR = 1.25, 95% CI = 1.02–1.50), not in other subgroups. However, no significant association was detected in any category of sleep duration or sleep quality in all models in the prospective analyses, and the results remained unchanged in the subgroup analyses of sex, age and body mass index.ConclusionsThe results of this study provide limited support for association of sleep duration and sleep quality with hypertension in middle-aged and older Chinese. Further studies are needed to confirm the results.     

Metabolic syndrome and its components in postmenopausal women living in southern Italy,Apulia region

Objectives

The goal of our study was to determine the prevalence of metabolic syndrome (MetS) and all its components, in a population of postmenopausal women aged over 45 years, consecutively accessed to our Heart Station, during 2014, for their first cardiac examination,furthermore to estimate their cardiovascular risk and the achievement of target blood values of main risk factors, according to current Guidelines.

Self-administered and yoked nicotine produce robust increases in blood pressure and changes in heart rate with modest effects of behavioral contingency in rats

Experimenter-administered nicotine produces reliable increases in blood pressure and changes in heart rate. However, an extensive literature demonstrates that the effects of psychoactive drugs are dependent on whether administration is contingent on behavior. The present study assessed the cardiovascular effects of nicotine and whether those effects vary as a function of whether nicotine was self-administered or response-independent. Rats were divided into three groups according to a yoked design. The pattern of infusions for each triad was determined by the animal self-administering nicotine; the other two animals received either yoked nicotine or saline. Heart rate and blood pressure were measured during eighteen daily, 1 h drug sessions by radiotelemetry. Each session was preceded and followed by a 20 minute period during which cardiovascular function was monitored in the operant chambers, but drug was not available. Acute exposure to yoked nicotine produced a rapid rise in blood pressure that was larger than the increase observed with self-administered nicotine. Additional infusions during the first session resulted in a similar sustained elevation in blood pressure in the nicotine groups. Over subsequent sessions, self-administered nicotine produced a larger effect on systolic blood pressure particularly early in each session, although for both self-administered and yoked nicotine the hypertensive effects waned partially with repeated test sessions. This decrease was fully accounted for by a pre-session decrease in pressure; relative to pre-session levels the strong hypertensive effects of nicotine persisted. Initial exposure to nicotine produced a short-lived bradycardia that in subsequent sessions was replaced with a longer-lasting nicotine-induced tachycardia; neither effect was related to the behavioral contingency of nicotine delivery. Together, these data provide a rich picture of the cardiovascular effects of nicotine. Effects of behavioral contingency were observed, but differences were limited. Other non-pharmacological factors such as baseline shifts potentially related to nicotine-associated cues deserve further attention.     

Prevention of paracentesis-induced circulatory dysfunction in cirrhosis: Standard vs half albumin doses. A prospective, randomized, unblinded pilot study

Background

Paracentesis-induced circulatory dysfunction is a well-known complication of large volume paracentesis. Albumin infusion (8 g of albumin/L of ascites removed) is effective in preventing it, but high costs and scant availability limit its use.

Aim

To compare standard vs half albumin doses.

Methods

Seventy cirrhotic patients treated with large volume paracentesis were randomized to receive intravenous albumin as prevention of paracentesis-induced circulatory dysfunction: group 1 (35 patients) received 4 g/L of ascites removed, group 2 (35 patients) received 8 g/L of ascites removed.

Results

The incidence of paracentesis-induced circulatory dysfunction (14% vs 20% in group 1 and group 2, respectively; p = ns), hyponatremia (9% vs 6%, p = ns) and renal impairment (0% in both groups) on the 6th day from paracentesis was similar between the two groups. After 6 months of follow-up, rates of survival and of recurrence of ascites requiring large volume paracentesis were not different between the two groups.

Conclusions

This unblinded, randomized, pilot study suggests that treatment with half doses of albumin is effective in the prevention of paracentesis-induced circulatory dysfunction and its related clinical complications in cirrhotic patients with tense ascites treated by large volume paracentesis. If confirmed, these results could support a significant costs reduction in the management of ascites in cirrhotic patients.     

Control of hypertension in rats using volatile components of leaves of Taxus chinensis var. mairei

Ethnopharmacological relevance

The leaves of Taxus chinensis var. mairei (Taxaceae) is used traditionally to fill pillows in some rural areas of China. Its volatile substances have been speculated to be capable of improving sleep quality, making blood pressure stable, and having diuretic capacity as recorded in Ancient Chinese Materia Medica. Using animal models and new technologies, we confirmed the hypotensive potential of volatile components from leaves of Taxus chinensis var. mairei (VCLT).

Materials and methods

VCLT was obtained by supercritical CO₂ extraction equipment from Taxus chinensis var. mairei fresh leaves. Hypertensive rats were pre-induced by intraperitoneal (i,p.) injection of Nω-Nitro-l-Ariginine (l-NNA) for 15 days (15 mg/kg, twice a day), then divided into 5 groups and subjected to the following treatments. l-NNA group (group 1) receiving l-NNA alone (15 mg/kg, i.p., twice per day for 6 weeks); in addition to receiving l-NNA same as group 1, Hydrochlorothiazide (HDZ) group (group 2) receiving HDZ (orally administration, 5 mg/kg, once per day for 6 weeks); VCLT groups (groups 3–5), including VCLT1, VCLT2, VCLT3. The VCLT rats were housed in an enclosed cage (2 rats/0.064 m³). VCLT was mixed well and sprayed on fresh leaves surface of Taxus chinensis var. mairei (100 ml/kg) with three dosages: 167 g/kg (VCLT1), 233 g/kg (VCLT2) and 333 g/kg (VCLT3), respectively. Systolic Blood Pressure (SBP), plasma nitric oxide (NO), plasma angiotensin II, postprandial blood glucose, fasting blood glucose and blood lipids were determined.

Results

VCLT prevented the increase of SBP and plasma angiotensin II in l-NNA treated rats. Although VCLT does not significantly reduce blood triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C), it decreases total cholesterol (TC) while increasing plasma NO levels in a dose-dependent manner.

Conclusion

VCLT can be used as a natural and supplementary reagents for the treatment of hypertension.