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Concept: Pulse pressure

173

To examine whether there is a difference in the association between high pulse pressure and proteinuria, independent of other blood pressure (BP) indices, such as systolic or diastolic BP, among subjects with diabetes, prediabetes, or normal glucose tolerance.

Concepts: Nutrition, Insulin, Cardiology, Blood pressure, Glucose tolerance test, The Association, Ventricle, Pulse pressure

40

Background Heat therapy has been suggested to improve cardiovascular function. However, the effects of hot sauna exposure on arterial compliance and the dynamics of blood flow and pressure have not been well documented. Thus, we investigated the short-term effects of sauna bathing on arterial stiffness and haemodynamics. Design The design was an experimental non-randomised study. Methods There were 102 asymptomatic participants (mean age, 51.9 years) who had at least one cardiovascular risk factor. Participants were exposed to a single sauna session (duration: 30 min; temperature: 73℃; humidity: 10-20%). Pulse wave velocity, augmentation index, heart rate, blood pressure, mean arterial pressure, pulse pressure, augmented pressure and left ventricular ejection time were assessed before, immediately after, and 30 min after a single sauna session. Results Sauna bathing led to reductions in pulse wave velocity, blood pressure, mean arterial pressure and left ventricular ejection time. Mean pulse wave velocity value before sauna was 9.8 m/s and decreased to 8.6 m/s immediately after sauna bathing ( p < 0.001 for difference), and was 9.0 m/s after the 30-minute recovery period ( p < 0.001 for analysis of variance). Systolic blood pressure was 137 mm Hg before sauna bathing, decreasing to 130 mm Hg after sauna ( p < 0.001), which remained sustained during the 30-minute recovery phase ( p < 0.001 for analysis of variance). After a single sauna session, diastolic blood pressure decreased from 82 to 75 mm Hg, mean arterial pressure from 99.4 to 93.6 mm Hg and left ventricular ejection time from 307 to 278 m/s ( p < 0.001 for all differences). Pulse pressure was 42.7 mm Hg before the sauna, 44.9 mm Hg immediately after the sauna, and reduced to 39.3 mm Hg after 30-minutes recovery ( p < 0.001 for analysis of variance). Heart rate increased from 65 to 81 beats/min post-sauna ( p < 0.001); there were no significant changes for augmented pressure and pulse pressure amplification. Conclusion This study shows that pulse wave velocity, systolic blood pressure, diastolic blood pressure, mean arterial pressure, left ventricular ejection time and diastolic time decreased immediately after a 30-minute sauna session. Decreases in systolic blood pressure and left ventricular ejection time were sustained during the 30-minute recovery phase.

Concepts: Blood, Myocardial infarction, Hypertension, Blood pressure, Artery, Ventricle, Pulse pressure, Mean arterial pressure

21

The technology of 3D-printing has allowed the production of entirely soft pumps with complex chamber geometries. We used this technique to develop a completely soft pneumatically driven total artificial heart from silicone elastomers and evaluated its performance on a hybrid mock circulation. The goal of this study is to present an innovative concept of a soft total artificial heart (sTAH). Using the form of a human heart, we designed a sTAH, which consists of only two ventricles and produced it using a 3D-printing, lost-wax casting technique. The diastolic properties of the sTAH were defined and the performance of the sTAH was evaluated on a hybrid mock circulation under various physiological conditions. The sTAH achieved a blood flow of 2.2 L/min against a systemic vascular resistance of 1.11 mm Hg s/mL (afterload), when operated at 80 bpm. At the same time, the mean pulmonary venous pressure (preload) was fixed at 10 mm Hg. Furthermore, an aortic pulse pressure of 35 mm Hg was measured, with a mean aortic pressure of 48 mm Hg. The sTAH generated physiologically shaped signals of blood flow and pressures by mimicking the movement of a real heart. The preliminary results of this study show a promising potential of the soft pumps in heart replacements. Further work, focused on increasing blood flow and in turn aortic pressure is required.

Concepts: Blood, Cardiology, Heart, Blood pressure, Artery, Vein, Cardiovascular system, Pulse pressure

6

Black men have higher blood pressure (BP) levels and consequently higher prevalence of hypertension compared with men from other ethnic groups in the United States. Socio-familial factors in childhood have been found to play an important role in hypertension, but few studies have examined this relationship among black men. We investigated whether childhood family living arrangements are independently associated with mean BP and hypertension in a cross-sectional sample of 515 unrelated black male participants aged ≥20 years enrolled in the Howard University Family Study between 2001 and 2008. Black men who lived with both parents compared with the reference group of men who never lived with both parents during their lifetime had lower systolic BP (-4.4 mm Hg [95% confidence interval {CI}, -7.84 to -0.96]), pulse pressure (-3.9 mm Hg [95% CI, -6.28 to -1.51]), and mean arterial BP (-2.0 mm Hg [95% CI, -4.44 to 0.51]). This protective effect was more pronounced among men who lived with both parents for 1 to 12 years of their lives; they had decreased systolic BP (-6.5 mm Hg [95% CI, -10.99 to -1.95]), pulse pressure (-5.4 mm Hg [95% CI, -8.48 to -2.28]), mean arterial pressure (-3.3 mm Hg [95% CI, -6.56 to 0.00]), and a 46% decreased odds of developing hypertension (odds ratio=0.54; 95% CI, 0.30 to 0.99). No statistically significant associations were found for diastolic BP. These results provide preliminary evidence that childhood family structure exerts a long-term influence on BP among black men.

Concepts: Statistics, Myocardial infarction, Hypertension, Blood pressure, Artery, Prehypertension, Pulse pressure, Mean arterial pressure

3

Frailty is associated with cognitive impairment and can be used to identify people at high risk for dementia. We developed a simple frailty (SF) score using a combination of low hand grip strength (<32.5 kg in men, <19.5 kg in women), and short one-leg standing time (<20 seconds). These can be easily measured in the clinician's office when seeing patients. We investigated the possible association between SF score and mild cognitive impairment (MCI) in a cross-sectional study with 838 independent middle-aged to elderly participants (319 men, mean age 65.1years). In total, 118 participants were diagnosed with MCI. A SF score of 2 was significantly associated with the presence of MCI (odds ratio 4.6, 95% confidence interval: 1.9-6.9, p = 0.0001) even after adjustment for age and sex. Stepwise regression analyses showed that a SF score of 2 was associated with the presence of MCI, independently of central pulse pressure and silent cerebral infarcts. These findings indicate that the SF score is a useful frailty parameter to predict MCI in an apparently independent population.

Concepts: Regression analysis, Statistics, Blood pressure, Old age, Prediction interval, Statistical terminology, Pulse pressure, Grip strength

3

Despite a common perception that fruit juice is healthy, fruit juice contains high amounts of naturally occurring sugar without the fibre content of whole fruit. Frequent fruit juice consumption may therefore contribute to excessive sugar consumption typical of Western society. Although excess sugar intake is associated with high blood pressure (BP), the association between habitual fruit juice consumption and BP is unclear. The present study investigated the association of fruit juice consumption with brachial and central (aortic) BP in 160 community dwelling adults. Habitual fruit juice consumption was measured using a 12 months dietary recall questionnaire. On the same day, brachial BP was measured and central (aortic) BP was estimated through radial artery applanation. Frequency of fruit juice consumption was classified as rare, occasional or daily. Those who consumed fruit juice daily, versus rarely or occasionally, had significantly higher central systolic BP (F (2, 134) = 6.09, p < 0.01), central pulse pressure (F (2, 134) = 4.16, p < 0.05), central augmentation pressure (F (2, 134) = 5.98, p < 0.01) and central augmentation index (F (2, 134) = 3.29, p < 0.05) as well as lower pulse pressure amplification (F (2, 134) = 4.36, p < 0.05). There were no differences in brachial BP. Central systolic BP was 3-4mmHg higher for those who consumed fruit juice daily rather than rarely or occasionally. In conclusion, more frequent fruit juice consumption was associated with higher central BPs.

Concepts: Blood, Hypertension, Blood pressure, Pulse, Prehypertension, Pulse pressure, Brachial artery, Radial artery

3

Blood pressure (BP) is a heritable risk factor for cardiovascular disease. To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP), we genotyped ∼50,000 SNPs in up to 87,736 individuals of European ancestry and combined these in a meta-analysis. We replicated findings in an independent set of 68,368 individuals of European ancestry. Our analyses identified 11 previously undescribed associations in independent loci containing 31 genes including PDE1A, HLA-DQB1, CDK6, PRKAG2, VCL, H19, NUCB2, RELA, HOXC@ complex, FBN1, and NFAT5 at the Bonferroni-corrected array-wide significance threshold (p < 6 × 10(-7)) and confirmed 27 previously reported associations. Bioinformatic analysis of the 11 loci provided support for a putative role in hypertension of several genes, such as CDK6 and NUCB2. Analysis of potential pharmacological targets in databases of small molecules showed that ten of the genes are predicted to be a target for small molecules. In summary, we identified previously unknown loci associated with BP. Our findings extend our understanding of genes involved in BP regulation, which may provide new targets for therapeutic intervention or drug response stratification.

Concepts: DNA, Blood, Myocardial infarction, Atherosclerosis, Hypertension, Blood pressure, Pulse pressure, Mean arterial pressure

2

Our goal was to perform a systematic review of the literature on the use of ketamine in traumatic brain injury (TBI) and its effects on intracranial pressure (ICP). All articles from MEDLINE, BIOSIS, EMBASE, Global Health, HealthStar, Scopus, Cochrane Library, the International Clinical Trials Registry Platform (inception to November 2013), reference lists of relevant articles, and gray literature were searched. Two reviewers independently identified all manuscripts pertaining to the administration of ketamine in human TBI patients that recorded effects on ICP. Secondary outcomes of effect on cerebral perfusion pressure, mean arterial pressure, patient outcome, and adverse effects were recorded. Two reviewers independently extracted data including population characteristics and treatment characteristics. The strength of evidence was adjudicated using both the Oxford and GRADE methodology. Our search strategy produced a total 371 citations. Seven articles, six manuscripts and one meeting proceeding, were considered for the review with all utilizing ketamine, while documenting ICP in severe TBI patients. All studies were prospective studies. Five and two studies pertained to adults and pediatrics, respectively. Across all studies, of the 101 adult and 55 pediatric patients described, ICP did not increase in any of the studies during ketamine administration. Three studies reported a significant decrease in ICP with ketamine bolus. Cerebral perfusion pressure and mean blood pressure increased in two studies, leading to a decrease in vasopressors in one. No significant adverse events related to ketamine were recorded in any of the studies. Outcome data were poorly documented. There currently exists Oxford level 2b, GRADE C evidence to support that ketamine does not increase ICP in severe TBI patients that are sedated and ventilated, and in fact may lower it in selected cases.

Concepts: Blood, Hypertension, Traumatic brain injury, Blood pressure, Intracranial pressure, Cerebral perfusion pressure, Pulse pressure, Mean arterial pressure

2

BACKGROUND: Exercise training is beneficial in health and disease. Part of the training effect materialises in the brainstem due to the exercise-associated somatosensory nerve traffic. Because active music making also involves somatosensory nerve traffic, we hypothesised that this will have training effects resembling those of physical exercise. METHODS: We compared two groups of healthy, young subjects between 18 and 30 years: 25 music students (13/12 male/female, group M) and 28 controls (12/16 male/female, group C), peers, who were non-musicians. Measurement sessions to determine resting heart rate, resting blood pressure and baroreflex sensitivity (BRS) were held during morning hours. RESULTS: Groups M and C did not differ significantly in age (21.4 ± 3.0 vs 21.2 ± 3.1 years), height (1.79 ± 0.11 vs 1.77 ± 0.10 m), weight (68.0 ± 9.1 vs 66.8 ± 10.4 kg), body mass index (21.2 ± 2.5 vs 21.3 ± 2.4 kg∙m(-2)) and physical exercise volume (39.3 ± 38.8 vs 36.6 ± 23.6 metabolic equivalent hours/week). Group M practised music daily for 1.8 ± 0.7 h. In group M heart rate (65.1 ± 10.6 vs 68.8 ± 8.3 beats/min, trend P =0.08), systolic blood pressure (114.2 ± 8.7 vs 120.3 ± 10.0 mmHg, P = 0.01), diastolic blood pressure (65.0 ± 6.1 vs 71.0 ± 6.2 mmHg, P < 0.01) and mean blood pressure (83.7 ± 6.4 vs 89.4 ± 7.1, P < 0.01) were lower than in group C. BRS in groups M and C was 12.9 ± 6.7 and 11.3 ± 5.8 ms/mmHg, respectively (P = 0.17). CONCLUSIONS: The results of our study suggest that active music making has training effects resembling those of physical exercise training. Our study opens a new perspective, in which active music making, additionally to being an artistic activity, renders concrete health benefits for the musician.

Concepts: Hypertension, Blood pressure, Artery, Medical signs, Ventricle, Systole, Pulse pressure, Mean arterial pressure

2

In stable ventilatory and metabolic conditions, changes in end-tidal carbon dioxide (EtCO(2)) might reflect changes in cardiac index (CI). We tested whether EtCO(2) detects changes in CI induced by volume expansion and whether changes in EtCO(2) during passive leg raising (PLR) predict fluid responsiveness. We compared EtCO(2) and arterial pulse pressure for this purpose.

Concepts: Oxygen, Carbon dioxide, Cardiology, Heart, Blood pressure, Thermodynamics, Artery, Pulse pressure