Relationship between systolic time intervals and arterial blood pressure

It has been suggested that systolic time intervals (STI) can be used to monitor the cardiac effects of antihypertensive treatments and also to evaluate hypertensive patients. STI changes observed in hypertensives have been ascribed to myocardial disease, although they could be due to the existence of a relationship between STI and blood pressure. A group of 37 subjects (18 normotensives and 19 hypertensives) with no signs of heart failure and left ventricular dysfunction were studied to examine the relationship of STI to blood pressure. Pacing with an external battery pulse generator was performed at the rate of 95 beats/min in order to eliminate differences in heart rate. STI were measured from good quality high speed (100 mm/s) recordings and the average value of 10 consecutive cardiac cycles was used for statistical analysis. Normal subjects showed significantly lower values of pre-ejection period (PEP), electromechanical systole (QS2), and pre-ejection period/left ventricular ejection time ratio (PEP/LVET). Moreover, a significant inverse relationship between diastolic pressure and LVET and significant direct relationships between diastolic pressure and PEP, systolic pressure and PEP, diastolic pressure and PEP/LVET, and between systolic pressure and PEP/LVET were demonstrated. We suggest to consider the relation of STI to blood pressure to provide regression equations to best appreciate and use STI.     

Calculated mean arterial pressure in the posterior tibial and radial artery pressure wave in newbown infants

Mean arterial pressure (MAP) is the area under the pressure wave averaged over the cardiac cycle, and therefore depends on pressure wave contour. A generally used rule of thumb to estimate MAP of peripheral arteries in adults is adding one-third of the arterial pulse pressure (PP) to diastolic arterial pressure (DAP). As peripheral pressure wave forms in neonates do not resemble adult peripheral wave forms, it may be expected that this rule of thumb does not hold for neonates. Previously, we found that MAP can be calculated by adding 50% PP to DAP in radial artery waves in neonates. In the present study, we investigated in neonates how MAP in the posterior tibial artery depends on systolic and diastolic pressure and we compared these findings to those found in the radial artery. Forty infants admitted for intensive care were studied. We analyzed 5000 invasively and accurately obtained blood pressure waves in the posterior tibial artery of 20 neonates and another 5000 waves similarly obtained from the radial artery in another group of 20 neonates. We found that MAP in posterior tibial artery waves is well approximated by adding 41.5±2.0% of PP to DAP, whereas MAP in radial artery waves can be calculated by adding 46.7±1.7% of PP to DAP. These values are significantly different (p<0.0001). In conclusion, the rule of thumb as used in the adult to find MAP, where 33% PP is added to DAP, does not hold for the newborn. We recommend to calculate MAP in the tibial artery by adding 40% of PP to DAP and in the radial artery by adding 50% of PP to DAP.Abbreviations ABP Arterial Blood Pressure - SAP Systolic Arterial Pressure - DAP Diastolic Arterial Pressure - MAP Mean Arterial Pressure - PP Pulse Pressure - MAP% (MAP-DAP)/(SAP-DAP)x100% i.e. the level of the MAP in the wave, expressed in % PP - IRDS Idiopathic Respiratory Distress Syndrome - PDA Patent Ductus Arteriosus     

Systolic and diastolic blood pressure percentiles by age and gender in Northeastern Iran

Hypertension (HTN) is a major risk factor for coronary artery disease. Its frequency is increasing globally. The aim of our study was to evaluate the reference range of blood pressure (BP) in the Iranian population stratified for age and gender. A total of 1449 subjects without diabetes, CVD, dyslipidemia, HTN history and with a normal BMI (18.5 ≤ BMI<25) were recruited in the present study. Participants were enrolled from the Mashhad stroke and heart atherosclerotic disorder study. Anthropometric indices and demographic data were collected by two health care specialists. A quantile regression model was used to estimate the expected systolic BP (SBP) and diastolic BP (DBP) at specific ages. A P-value of <.05 was considered significant for all analyses. All statistical analyses were performed using R (version 3.4.1) and SPSS software. The population included more men than women (51.6% vs. 48.4%). The mean and standard deviation of age in men (47.5 ± 8.4) was 2 years higher than women (45.63 ± 7.9; P < .001). SBP and DBP were higher in men than women (P < .001). By using a quantile regression model, we concluded that the 5th to 90th percentile of SBP in men, aged 30–69 years, ranged from 95 to 148.08 mm Hg and in women ranged from 86.66 to 140 mm Hg. The 5th to 90th percentile of DBP in men, aged 30–69 years, ranged from 60 to 91.66 mm Hg and in women ranged from 60 to 91.22 mm Hg. We have, for the first time, established the BP percentiles (1st, 5th, 10th, 50th, 90th, 95th, 99th) in an Iranian population stratified by age and gender. These data suggest that a local program for health promotion is necessary for the early identification of HTN in adults aged ≥30 years.     

Association of low diastolic blood pressure with all-cause death among US adults with normal systolic blood pressure

Although the effect of intensive systolic blood pressure lowering is widely recognized, treatment-related low diastolic blood pressure still worrisome. This was a prospective cohort study based on the National Health and Nutrition Examination Survey. Adults (≥20 years old) with guideline-recommended blood pressure were included and pregnant women were excluded. Survey-weighted logistic regression and cox models were used for analysis. A total of 25 858 participants were included in this study. After weighted, the overall mean age of the participants was 43.17 (16.03) years, including 53.7% women and 68.1% non-Hispanic white. Numerous factors were associated with low DBP (<60 mmHg), including advanced age, heart failure, myocardial infarction, and diabetes. The use of antihypertensive drugs was also associated with lower DBP (OR, 1.52; 95% CI, 1.26–1.83). DBP of less than 60 mmHg were associated with a higher risk of all-cause death (HR, 1.30; 95% CI, 1.12–1.51) and cardiovascular death (HR, 1.34; 95% CI, 1.00–1.79) compared to those with DBP between 70 and 80 mmHg. After regrouping, DBP <60 mmHg (no antihypertensive drugs) was associated with a higher risk of all-cause death (HR, 1.46; 95% CI, 1.21–1.75). DBP <60 mmHg after taking antihypertensive drugs was not associated with a higher risk of all-cause death (HR, 0.99; 95% CI, 0.73–1.36). Antihypertensive drug is an important factor contributing to DBP below 60 mmHg. But the pre-existing risk does not increase further with an additional reduction of DBP after antihypertensive drugs treatment.     

Gender difference in the relationship between uric acid and pulse pressure among Korean adults

Hyperuricemia is associated with cardiovascular disease, but the relationship between uric acid (UA) and pulse pressure (PP) is unclear. Therefore, the present study assesses the relationship between UA and PP among Korean adults. Data from 6,310 subjects (2,800 men and 3,510 women) in the seventh Korean National Health and Nutrition Examination Survey (2016) were analyzed. After adjusting for related variables, the odds ratios (ORs) of hyperuricemia (UA ≥ 7.0 mg/dL in men or ≥ 6.0 mg/dL in women) in the high PP group (PP > 65.0 mmHg) in overall populations (OR, 1.563; 95% confidence interval [CI], 1.144–2.136) and women (OR, 1.631; 95% CI, 1.046–2.544) were significantly higher than those in normal PP, but not in men (OR, 1.309; 95% CI, 0.840–2.040). In conclusion, uric acid was positively associated with pulse pressure in women, but not in men.     

Central aortic systolic blood pressure can predict prolonged QTc duration better than brachial artery systolic blood pressure in rural community residents

Objectives: Previous studies have suggested that prolonged electrocardiogram QTc duration was independent risk factor for both increased cardiovascular and all-cause mortality, but there was no dating about the relationship between central aortic systolic blood pressure (CASP) and QTc duration. The aim of this study was to analyze the relationship between CASP and QTc duration, and assess whether CASP can predict prolonged QTc duration more than BSBP. Methods: A total of 500 patients were enrolled in this study, central and brachial aortic blood pressure and electrocardiogram QTc duration were measured. Pearson correlation was assessed for determining the associations of QTc duration with clinical conditions. Multivariate logistic regression analyses were performed to determine the independent predictor of prolonged QTc duration. Receiver operating characteristic (ROC) curve was used to evaluate the utility of blood pressure for prolonged QTc duration. Results: We found QTc durations were significantly positive with CASP (r = 0.308, p < 0.001), BSBP (r = 0.227, p < 0.001), and age (r = 0.154, p = 0.010), but negatively related to heart rate (r = ?440, p < 0.001). A multiple logistic regression analysis demonstrated that the CASP was an independent determinant of prolonged QTc (OR = 1.648; 95%CI: 1.032, 2.101; p < 0.001). CASP had a better predictive value for prolonged QTc duration than (AUC: 0.771 vs. 0.646, p < 0.001) BSBP. Conclusion: Our results suggested that the non-invasive CASP is independently correlated with QTc duration, and CASP can predict prolonged QTc duration more than BSBP.     

高血压患者血清总胆红素水平与血压变异性的关系

目的 探讨血清总胆红素水平对高血压患者的血压水平及血压变异性的影响.方法 本研究为回顾性观察性研究,连续纳入在2019年9月至2020年3月在宣城市人民医院心血管内科住院并确诊为高血压的患者,并完善动态血压及动态心电图检查.本研究以动态血压测量参数中24 h收缩压标准差和24 h舒张压标准差作为血压变异性指标.应用多元...     

中心动脉血压分数与冠状动脉病变程度相关性研究

目的分析国人中心动脉血压分数与冠心病病变严重程度的相关性。方法描记人选研究对象中心压力曲线,计算中心收缩压分数（FSP）、中心舒张压分数（FDP）,以冠状动脉造影结果作为分组依据,经统计分析FSP、FDP与冠状动脉病变及其严重程度的关系。结果冠心病及非冠心病组中心动脉FSP、FDP差异有统计学意义（P〈0．01）。经Logistic回归分析示：中心FSP、FDP、性别、年龄、APOB为冠心病的独立危险因素（P〈0．01）,其FSP及FDP的OR值分别为1．23和O．66。冠脉三支病变组与单支、双支病变组比较,中心动脉FSP、FDP差异有统计学意义（P〈0．0t）。中心FSP、FDP为冠脉三支病变的独立危险因素（P〈0．01）,其FSP及FDP的OR值分别为1．25和0．63。中心FSP、FDP与冠脉积分具有显著相关性（P〈0．01）,中心动脉FSP与FDP的矗值分别为0．182和0．193。结论中心动脉FSP、FDP为预测冠心病及病变严重程度的独立危险因素,是预测冠心病发生、发展的良好指标。     

Comparison between oscillometric and intra-arterial blood pressure measurements in ill preterm and full-term neonates

Conflicting data exist regarding the accuracy of the oscillometric method of blood pressure (BP) measurement in neonates. There is limited data regarding intra-arterial BP trends in neonates. We aimed to determine the accuracy of oscillometric BP measurements and to evaluate the BP distributions in ill neonates. A total of 1492 simultaneously obtained oscillometric and intra-arterial (umbilical arterial [UAC] or radial arterial) BP measurements were used for comparisons and 125,580 intra-arterial BP readings were used to the evaluate BP distribution. There was a statistically significant difference (P < .0001) between the oscillometric and radial mean arterial BP (MAP) 4.8 ± 9.8 mm Hg, systolic BP 8.3 ± 11.6 mm Hg, diastolic BP 4.3 ± 9.3 mm Hg and between the oscillometric and UAC systolic BP 5.2 ± 11.9 mm Hg and diastolic BP −0.8 ± 10.4 mm Hg. The MAP increased with increases in weight (35.3 ± 4.92 mm Hg/kg), post-menstrual age (−0.29 ± 1.41 mm Hg/week) and advanced gestational age at birth (13.12 ± 0.90 mm Hg/week). Oscillometric BP measurements are not equivalent to the intra-arterial (UAC or radial arterial) BP in ill neonates. The BP increases with increase in weight, gestational age at birth, and post-menstrual age in ill neonates.     

Decreasing population blood pressure: 15 years of follow-up in the Copenhagen City Heart Study (CCHS)

Objective: Population blood pressure (BP) levels from a longitudinal study were analysed for trends during a period of 15 years. Trends from unadjusted data are reported as well as trends adjusted for major cardiovascular (CV) risk factors and use of antihypertensive therapy, thus allowing assessment of independent BP trends. Design: The Copenhagen City Heart Study is a longitudinal epidemiological study of CV risk in a random population sample of both genders aged 20 and above. Three cross-sectional population surveys were performed: 1976-78 (n = 14000), 1981-83 (n = 12675) and 1991-94 (n = 9661). Methods: BP was measured by a London School of Hygiene Sphygmomanometer. Weight and height were measured and body mass index (BMI) calculated. Non-fasting plasma cholesterol was determined. A questionnaire concerning smoking status and diabetes was completed. Measurement methods were strictly standardized and unchanged in the three cross-sectional surveys. Results: Unadjusted systolic BP (SBP) levels decreased during 15 years of follow-up, and unadjusted diastolic BP (DBP) levels increased. An investigation of the effect of major CV risk factors, both singly and jointly on BP levels, revealed a pattern of correlations contributing to BP variability. Adjustments for BMI, cholesterol, diabetes, use of antihypertensive therapy and smoking status were made in the final analyses of BP trend. The adjusted trend model demonstrated that SBP levels remained lower than SBP levels in the first survey. DBP levels increased slightly. Conclusions: The results demonstrate a decrease in population SBP. The decrease is independent of major CV risk factors. Possible contributing factors are discussed.     

Prediction of cardiovascular events from systolic or diastolic blood pressure

Over time, a focus on blood pressure has transferred from diastolic pressure to systolic pressure. Formal analyses of differences in predictive value are scarce. Our goal of the study was whether office SBP adds prognostic information to office DBP and whether both 24‐h ambulatory SBP and 24‐h ambulatory DBP is specifically important. The authors examined 2097 participants from a population cohort recruited in Copenhagen, Denmark. Cause‐specific Cox regression was performed to predict 10‐year person‐specific absolute risks of fatal and non‐fatal cardiovascular (CV) events. Also, the time‐dependent area under the receiver operator curve (AUC) was utilized to evaluate discriminative ability. The calibration plots of the models (Hosmer‐May test) were calculated as well as the Brier score which combines (discrimination and calibration). Adding both 24‐h ambulatory SBP and 24‐h ambulatory diastolic blood pressure did not significantly increase AUC for CV mortality and CV events. Moreover, adding both office SBP and office DBP did not significantly improve AUC for both CV mortality and CV events. The difference in AUC (95% confidence interval; p‐value) was .26% (‐.2% to .73%; .27) for 10‐year CV mortality and .69% (‐.09% to 1.46%; .082) for 10‐year risk of CV events. The difference in AUC was .12% (‐.2% to .44%; .46) for 10‐year CV mortality and .04% (‐.35 to .42%; .85) for 10‐year risk of CV events. Moreover, for both CV mortality and CV events, office SBP did not improve prognostic information to office DBP. In addition, the Brier scores of office BP in both CV mortality and CV events were .078 and .077, respectively. Furthermore, the Brier scores were .077 and .078 in CV mortality and CV events of 24‐h ambulatory. For the average population as those participating in a population survey, the 10‐year discriminative ability for long‐term predictions of CV death and CV events is not improved by adding systolic to diastolic blood pressure. This finding is found for ambulatory as well as office blood pressure.     

Evaluation of sustained blood pressure elevation in children

ObjectivesTo document the prevalence and etiology of sustained blood pressure elevation in children.Methods & resultsIt is a school-based prospective cross-sectional study involving healthy school children in age group of 5–15 years (both sexes). Children with any acute or chronic illnesses and the intersexes were excluded from the study group. Total number of hypertensive children were 37. Of these 37 cases, 23 hypertensive cases were boys and 14 were girls. All these hypertensive children maintained their blood pressure above +2SD for the corresponding age and sex. Male and female ratio of hypertensive cases was 62:38. All were primary hypertensives as per working definition. Majority belonged to Class II socio-economic status.ConclusionHypertension in children is very rare with a prevalence of 0.38% and majority had primary hypertension.     

Association between hypertension and cognitive function: A cross‐sectional study in people over 45 years old in China

This cross‐sectional study aimed to evaluate the associations of characteristics of hypertension, including hypertension status, duration, blood pressure (BP), and pulse pressure (PP), with two cognitive functions—episodic memory and executive function, in people aged over 45 years. Using 2013 survey of the China Health and Retirement Longitudinal Study (CHARLS) and weighted multiple linear regression, data from 6,732 participants were utilized. After fully adjusted in full sample, a significantly (P < 0.05) negative association was found between treated but uncontrolled hypertension and cognition. In people aged 45‐59 years, there was no significant association between hypertension and cognition. However, in people aged ≥60 years, the systolic blood pressure (SBP) and PP showed significantly adverse correlations to cognition. The negative association of untreated, treated but uncontrolled hypertension, and elevated PP with cognition increased with aging. In conclusion, this study shows the correlation between hypertension and cognition was age‐dependent with greater correlation in older people; uncontrolled hypertension and PP may be used as predictors of the cognitive decline in people ≥75 years.     

经皮无创血气监测在危重新生儿中的应用价值

目的探讨新生儿使用经皮二氧化碳分压(TcPCO_2)及经皮氧分压(TcPO_2)监测的临床应用价值。方法选取2016-04-01~2017-03-31入住新生儿重症监护室的需呼吸支持的危重新生儿44例,进行持续TcPCO_2、TcPO_2监测,将监测结果与动脉血二氧化碳分压(PaCO_2)、动脉血氧分压(PaO_2)结果进行比较。结果共纳入44例患儿,收集188组数据,Pearson积差相关分析结果显示TcPCO_2与PaCO_2、TcPO_2与PaO_2有良好的相关性,Pearson系数分别为0.886、0.676,P0.005。结论 TcPCO_2、TcPO_2监测可以准确评估危重新生儿的PaCO_2、PaO_2,特别是PaCO_2。TcPCO_2、TcPO_2持续监测的使用可以减少对危重新生儿的采血次数、疼痛刺激。     

Relationship between postoperative mean systolic blood pressure and contrast-induced nephropathy in patients undergoing cardiac catheterization

Background There were few studies to explore the relationship between postoperative mean systolic blood pressure (PMSBP) within 6 h after cardiac catheterization and contrast-induced nephropathy (CIN). Methods From June 2010 to February 2013, 299 consecutive patients undergoing cardiac catheterization were recruited. Patients were classified into quartiles based on PMSBP ( < 112, 112-120, 121-131, and > 132 mmHg). Baseline data, CIN incidence and in-hospital outcomes were compared between the groups. Logistic regression was used to assess the relationship between PMSBP and CIN. Results CIN occurred in 26(8.7%) patients. The incidence of CIN in PMSBP quartiles were 15.3% (11 / 72), 15.1% (11 / 73), 2.4% (2 / 82) and 2.8% (2 / 72) (P = 0.001) respectively. There were no significant difference in in-hospital death , renal replacement therapy and intra-aortic balloon pump (IABP) support between the groups (P > 0.05). Univariate logistic regression analysis showed that PMSBP was significantly associated with CIN (OR = 0.956, 95% CI: 0.928-0.986, P = 0.004). Multivariate logistic regression analysis found that after adjusting baseline estimate glomerular filtration rate, age > 75 years and acute myocardial infarction, PMSBP < 120 mmHg was still an independent risk factor for CIN (OR = 5.049, 95% CI:1.820-14.009, P = 0.002). Conclusions Lower PMSBP was significantly associated with an increased risk of CIN. PMSBP < 120 mmHg was an independent risk factor for CIN. Intensive blood-pressure control after cardiac catheterization might increase the risk of CIN.     

Exercise induced increase in diastolic blood pressure. Is it an indicator of coronary artery disease?

It has been previously reported that an increase in diastolic blood pressure greater than 15 mmHg comparing values at rest with those on treadmill exercise, with or without ST changes, enhances the probability of coronary artery disease. To investigate whether the diastolic blood pressure variation keeps its diagnostic value during upright bicycle exercise, we evaluated the diastolic blood pressure variations in 111 patients with angiographically documented coronary artery disease without previous myocardial infarction and in 53 patients with normal coronary arteries undergoing maximal stress testing on a bicycle ergometer. The sensitivity of diastolic blood pressure (DBP) variations to detect coronary artery disease was 66%, the specificity 32%, the positive predictive value 67%, the negative predictive value 31% and the predictive accuracy 55%. The respective values for ST depression were 83% (P less than 0.001 vs DBP variations), 53% (P less than 0.05 vs DBP variations), 64% (P less than 0.05 vs DBP variations) and 75% (P less than 0.001 vs DBP variations). Forty-nine of the 75 patients with multivessel coronary artery disease and 60 of the 89 patients without coronary artery disease or with single vessel disease had abnormal DBP variations (sensitivity 65; specificity 33%). The sensitivity of ST segment depression in predicting multivessel disease was 91% (P less than 0.001 vs DBP variations), and the specificity 42%. Thus, for bicycle ergometer exercise testing, ST segment depression seems to be more accurate than DBP variations in the diagnosis of coronary artery disease.     

Usefulness of ankle‐brachial index calculated using diastolic blood pressure for prediction of mortality in patients with acute myocardial infarction

A low ankle‐brachial index (ABI) calculated using systolic blood pressure (SBP) (ABIsbp) is associated with poor cardiovascular outcome in patients with acute myocardial infarction (AMI). ABI is always calculated using SBP clinically. However, there was no study investigating ABI calculated using mean artery pressure (MAP)(ABImap) and diastolic blood pressure (DBP)(ABIdbp) for mortality prediction in AMI patients. Therefore, our study was aimed to investigate the issue. 199 AMI patients were enrolled. Different ABIs were measured by an ABI‐form device. The median follow‐up to mortality was 64 months. There were 40 cardiovascular and 137 all‐cause mortality. The best cutoff values of ABImbp and ABIdbp for mortality prediction were 0.91 and 0.78, respectively. After multivariate analysis, only ABIdbp and ABIdbp < 0.78 could predict cardiovascular mortality (P ≤ .047). However, all of six ABI parameters, including ABIsbp, ABImap, ABIdbp, ABIsbp < 0.90, ABImap < 0.91, and ABIdbp < 0.78, could predict all‐cause mortality (P ≤ .048). In a direct comparison of six ABI models for prediction of all‐cause mortality, basic model + ABIdbp <0.78 had the highest predictive value (P ≤ .025). In conclusion, only ABIdbp and ABIdbp < 0.78 could predict cardiovascular and all‐cause mortality after multivariate analysis in our study. Furthermore, when adding into a basic model, ABIdbp < 0.78 had the highest additively predictive value for all‐cause mortality in the six ABI parameters. Hence, calculation of ABI using DBP except SBP might provide an extra benefit in prediction of cardiovascular and all‐cause mortality in AMI patients.     

高血压患者的中心动脉压、肱动脉压与脉压

目的比较高血压患者中心动脉压、肱动脉压、脉压,了解脉压随年龄变化趋势。方法随机选取728名高血压患者,其中男性410例,女性318例,年龄24～88岁,测量患者的中心动脉压、肱动脉压,根据年龄进行分组,分析脉压与年龄之间变化趋势。结果患者中心动脉收缩压、脉压低于肱动脉收缩压、脉压,差异有显著统计学意义(P均0.01);中心动脉舒张压高于肱动脉舒张压,两者之间差异也有显著统计学意义(P0.01)。男性肱动脉及中心动脉脉压随着年龄增长呈先下降后上升的趋势,女性两者均呈逐渐上升趋势。结论中心动脉压和肱动脉压有显著差异性,中心动脉与肱动脉脉压随年龄变化的趋势一致。