Camphor-Crataegus berry extract combination dose-dependently reduces tilt induced fall in blood pressure in orthostatic hypotension.

In order to test the efficacy of a combination of natural D-camphor and an extract of fresh crataegus berries (Korodin Herz-Kreislauf-Tropfen) on orthostatic hypotension, two similar, controlled, randomized studies were carried out in a balanced crossover design in 24 patients each with orthostatic dysregulation. The camphor-crataegus berry combination (CCC) was orally administered as a single regimen in 3 different dosages of 5 drops, 20 drops and 80 drops; a placebo with 20 drops of a 60% alcoholic solution served as control. Orthostatic hypotension was assessed with the tilt table test before and after medication. Source data of both studies were pooled and meta-analytically evaluated for all 48 patients. CCC drops decreased the orthostatic fall in blood pressure versus placebo, as almost uniformly established at all times by mean arterial pressure and diastolic blood pressure. Mean arterial pressure demonstrated the very fast onset of action by a clearly dose-dependent statistically significant effect even after 1-minute orthostasis. Increase of mean arterial pressure as compared to the orthostasis test before medication was on average 4.5 mmHg. CCC affected diastolic blood pressure after 1 minute of orthostasis in all dosages as compared to placebo. A statistically significant effect of the highest dose of 80 drops on diastolic blood pressure could be demonstrated after 1-, 3-, and 5-minute orthostasis. The hemodynamic findings of a stabilizing effect on arterial pressure in orthostasis corroborate the long-term medical experience with CCC and justify the indication orthostatic hypotension.     

Orthostatic hypotension in aging humans

We tested the hypothesis that hypotension occurred in older adults at the onset of orthostatic challenge as a result of vagal dysfunction. Responses of heart rate (HR) and mean arterial pressure (MAP) were compared between 10 healthy older and younger adults during onset and sustained lower body negative pressure (LBNP). A younger group was also assessed after blockade of the parasympathetic nervous system with the use of atropine or glycopyrrolate and after blockade of the beta(1)-adrenoceptor by use of metoprolol. Baseline HR (older vs. younger: 59 +/- 4 vs. 54 +/- 1 beats/min) and MAP (83 +/- 2 vs. 89 +/- 3 mmHg) were not significantly different between the groups. During -40 Torr, significant tachycardia occurred at the first HR response in the younger subjects without hypotension, whereas significant hypotension [change in MAP (DeltaMAP) -7 +/- 2 mmHg] was observed in the elderly without tachycardia. After the parasympathetic blockade, tachycardiac responses of younger subjects were diminished and associated with a significant hypotension at the onset of LBNP. However, MAP was not affected after the cardiac sympathetic blockade. We concluded that the elderly experienced orthostatic hypotension at the onset of orthostatic challenge because of a diminished HR response. However, an augmented vasoconstriction helped with the maintenance of their blood pressure during sustained LBNP.     

Single Agent Antihypertensive Therapy and Orthostatic Blood Pressure Behaviour in Older Adults Using Beat-to-Beat Measurements: The Irish Longitudinal Study on Ageing

Background

Impaired blood pressure (BP) stabilisation after standing, defined using beat-to-beat measurements, has been shown to predict important health outcomes. We aimed to define the relationship between individual classes of antihypertensive agent and BP stabilisation among hypertensive older adults.

Methods

Cross-sectional analysis from The Irish Longitudinal Study on Ageing, a cohort study of Irish adults aged 50 years and over. Beat-to-beat BP was recorded in participants undergoing an active stand test. We defined grade 1 hypertension according to European Society of Cardiology criteria (systolic BP [SBP] 140-159mmHg ± diastolic BP [DBP] 90-99mmHg). Outcomes were: (i) initial orthostatic hypotension (IOH) (SBP drop ≥40mmHg ± DBP drop ≥20mmHg within 15 seconds [s] of standing accompanied by symptoms); (ii) sustained OH (SBP drop ≥20mmHg ± DBP drop ≥10mmHg from 60 to 110s inclusive); (iii) impaired BP stabilisation (SBP drop ≥20mmHg ± DBP drop ≥10mmHg at any 10s interval during the test). Outcomes were assessed using multivariable-adjusted logistic regression.

Results

A total of 536 hypertensive participants were receiving monotherapy with a renin-angiotensin-aldosterone-system inhibitor (n = 317, 59.1%), beta-blocker (n = 89, 16.6%), calcium channel blocker (n = 89, 16.6%) or diuretic (n = 41, 7.6%). A further 783 untreated participants met criteria for grade 1 hypertension. Beta-blockers were associated with increased odds of initial OH (OR 2.05, 95% CI 1.31–3.21) and sustained OH (OR 3.36, 95% CI 1.87–6.03) versus untreated grade 1 hypertension. Multivariable adjustment did not attenuate the results. Impaired BP stabilisation was evident at 20s (OR 2.59, 95% CI 1.58–4.25) and persisted at 110s (OR 2.90, 95% CI 1.64–5.11). No association was found between the other agents and any study outcome.

Conclusion

Beta-blocker monotherapy was associated with a >2-fold increased odds of initial OH and a >3-fold increased odds of sustained OH and impaired BP stabilisation, compared to untreated grade 1 hypertension. These findings support existing literature questioning the role of beta-blockers as first line agents for essential hypertension.     

How many sphygmomanometric cuff inflations are necessary to obtain a hemodynamic baseline?

The purpose of this study was to determine the minimum number of consecutive blood pressure cuff inflations required to obtain seated stable resting baseline measurements of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP). Sixty male college students aged 18 to 31 years volunteered as study subjects. Thirteen observations of HR, SBP, DBP, and MAP were recorded at 90-second intervals for each subject using a Critikon-Dinamap monitor. Stable readings for SBP and MAP were obtained in 6.5 minutes or 3 to 5 cuff inflations in the population tested. Using this procedure, additional age- and gender-specific norms could be established for normal and hypertensive subjects. Knowing the approximate quantity and frequency of blood pressure cuff inflations needed to generate baseline minimum measurements of HR, SBP, DBP, and MAP will be helpful in studies of cardiovascular reactivity, as well as for clinical and psychophysiologic treatment of hypertension.     

How well can blood pressure be controlled? Progress report on the Systolic Hypertension in Europe Follow-Up Study (Syst-Eur 2)

Background

The randomised, double-blind, placebo-controlled Systolic Hypertension in Europe trial (Syst-Eur 1) proved that blood pressure (BP) lowering therapy starting with nitrendipine reduces the risk of cardiovascular complications in elderly patients with isolated systolic hypertension. In an attempt to confirm the safety of long-term antihypertensive therapy based on a dihydropyridine, the Syst-Eur patients remained in open follow-up after the end of Syst-Eur 1. This paper presents the second progress report of this follow-up study (Syst-Eur 2). It describes BP control and adherence to study medications.

Methods

After the end of Syst-Eur 1 all patients, treated either actively or with placebo, were invited either to continue or to start antihypertensive treatment with the same drugs as previously used in the active treatment arm. In order to reach the target BP (sitting SBP <150 mmHg), the first line agent, nitrendipine, could be associated with enalapril and/or hydrochlorothiazide.

Results

Of the 3787 eligible patients, 3516 (93%) entered Syst-Eur 2. At the last available visit, 72% of the patients were taking nitrendipine. SBP/DBP at entry in Syst-Eur 2 averaged 160/83 mmHg in the former placebo group and 151/80 mmHg in the former active-treatment group. At the last follow-up visit SBP/DBP in the patients previously randomised to placebo or active treatment had decreased by 16/5 mmHg and 7/5 mmHg, respectively. The target BP was reached by 74% of the patients.

Conclusion

Substantial reductions in systolic BP may be achieved in older patients with isolated systolic hypertension with a treatment strategy starting with the dihydropyridine calcium-channel blocker, nitrendipine, with the possible addition of enalapril and/or hydrochlorothiazide.     

Circadian pattern of blood pressure,heart rate,and double product in liver glycogen storage disease

The objective of this study was to determine systolic, diastolic, and mean arterial blood pressure (SBP, DBP, and MAP), heart rate (HR), double-product (DP: SBP x HR), and activity levels and their 24h pattern in liver glycogen storage disease (LGSD) patients. A case series of 12 (11 pediatric and one adult) diurnally active LGSD (seven type I, three type III, and two type IX) subjects were simultaneously assessed by 24h ambulatory blood pressure monitoring and wrist actigraphy. Nine subjects were judged to be hypertensive based on the criterion of an elevated 24h mean SBP and/or DBP being elevated beyond reference standards or the SBP and/or DBP load (percentage of time BP exceeds normal values) being greater than 25%. Two of the three other subjects, not viewed as hypertensive based on their 24h average SBP or DBP, exhibited daytime or nighttime SBP and/or DBP load hypertension. Each study variables displayed statistically significant (p < 0.001) group circadian rhythmicity. The SBP, DBP, and MAP displayed comparable 24h patterns of appreciable amplitude (total peak-trough variation equal to 17.7, 23.6, and 19.6%, respectively, of the 24h mean) with highest values (orthophase) occurring approximately 11 h after the commencement of daytime activity. The sleep-time trough (bathyphase) occurred approximately 4.5 h before morning awakening. The statistically significant (p < 0.006) circadian rhythms of HR (amplitude equal to 33.2% of the 24h mean) and DP (amplitude equal to 49.4% of the 24h mean) peaked earlier, approximately 7.4 h into the daytime activity span. The sleep-time trough occurred approximately 3 h before morning awakening. The 24h pattern in the cardiovascular variables was correlated with the 24h pattern of activity, with r ranging from 0.50 for DBP to 0.39 for HR.     

The relationship of age, body mass index and waist circumference with blood pressure in Bengalee Hindu male jute mill workers of Belur, West Bengal, India

A cross-sectional study of 150 adult Bengalee Hindu male jute mill workers of Belur, a suburb of Kolkata, West Bengal, India, was undertaken to study the relationship of age, body mass index (BMI) and waist circumference (WC) with systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure. The mean age and the BMI of the subjects were 40.7 years (S.D. = 15.2) and 23.2 kg/m2 (S.D. = 3.2), respectively. The mean SBP, DBP and MAP were 124.7 mmHg (S.D. = 7.8), 81.5 mmHg (S.D. = 5.7) and 95.9 mmHg (S.D. = 6.1), respectively. Age had similar significant (p < 0.001) correlations with BMI and WC. Age and WC were significantly correlated (p < 0.001) with all the three blood pressure variables. In general, the correlations of BMI with SBP (r = 0.24, p < 0.01), DBP (r = 0.15, n.s.) and MAP (r = 0.19, p < 0.05) were weaker. Age controlled multiple regression analyses demonstrated that BMI did not have a significant effect of any blood pressure variable. However, WC had a significant impact (p < 0.0001) on SBP (t = 7.068), DBP (t = 5.190) and MAP (t = 6.387), even after adjusting for the effect of age. Moreover, even after age adjustment, percent variations in SBP (20.7%), DBP (12.5%) and MAP (17.2%) explained by WC were high. This significant impact (p < 0.0001) of WC on SBP (t = 9.426), DBP (t = 8.349) and MAP (t = 9.642) remained even after controlling for the combined effects of age and BMI.     

Hypohydration and prior heat stress exacerbates decreases in cerebral blood flow velocity during standing.

Hypohydration is associated with orthostatic intolerance; however, little is known about cerebrovascular mechanisms responsible. This study examined whether hypohydration reduces cerebral blood flow velocity (CBFV) in response to an orthostatic challenge. Eight subjects completed four orthostatic challenges (temperate conditions) twice before (Pre-EU and Pre-Hyp) and following recovery from passive heat stress ( approximately 3 h at 45 degrees C, 50% relative humidity, 1 m/s air speed) with (Post-EU) or without (Post-Hyp) fluid replacement of sweat losses (-3% body mass loss). Measurements included CBFV, mean arterial pressure (MAP), heart rate (HR), end-tidal CO(2), and core and skin temperatures. Test sessions included being seated (20 min) followed by standing (60 s) then resitting (60 s) with metronomic breathing (15 breaths/min). CBFV and MAP responses to standing were similar during Pre-EU and Pre-Hyp. Standing Post-Hyp exacerbated the magnitude (-28.0 +/- 1.4% of baseline) and duration (9.0 +/- 1.6 s) of CBFV reductions and increased cerebrovascular resistance (CVR) compared with Post-EU (-20.0 +/- 2.1% and 6.6 +/- 0.9 s). Standing Post-EU also resulted in a reduction in CBFV, and a smaller decrease in CVR compared with Pre-EU. MAP decreases were similar for Post-EU (-18 +/- 4 mmHg) and Post-Hyp (-21 +/- 5 mmHg) from seated to standing. These data demonstrate that despite similar MAP decreases, hypohydration, and prior heat stress (despite apparent recovery) produce greater CBFV reduction when standing. These observations suggest that hypohydration and prior heat stress are associated with greater reductions in CBFV with greater CVR, which likely contribute to orthostatic intolerance.     

Influence of acute alcohol ingestion on sympathetic neural responses to orthostatic stress in humans

Acute alcohol consumption is reported to decrease mean arterial pressure (MAP) during orthostatic challenge, a response that may contribute to alcohol-mediated syncope. Muscle sympathetic nerve activity (MSNA) increases during orthostatic stress to help maintain MAP, yet the effects of alcohol on MSNA responses during orthostatic stress have not been determined. We hypothesized that alcohol ingestion would blunt arterial blood pressure and MSNA responses to lower body negative pressure (LBNP). MAP, MSNA, and heart rate (HR) were recorded during progressive LBNP (-5, -10, -15, -20, -30, and -40 mmHg; 3 min/stage) in 30 subjects (age 24 ± 1 yr). After an initial progressive LBNP (pretreatment), subjects consumed either alcohol (0.8 g ethanol/kg body mass; n = 15) or placebo (n = 15), and progressive LBNP was repeated (posttreatment). Alcohol increased resting HR (59 ± 2 to 65 ± 2 beats/min, P < 0.05), MSNA (13 ± 3 to 19 ± 4 bursts/min, P < 0.05), and MSNA burst latency (1,313 ± 16 to 1,350 ± 17 ms, P < 0.05) compared with placebo (group × treatment interactions, P < 0.05). During progressive LBNP, a pronounced decrease in MAP was observed after alcohol but not placebo (group × time × treatment, P < 0.05). In contrast, MSNA and HR increased during all LBNP protocols, but there were no differences between trials or groups. However, alcohol altered MSNA burst latency response to progressive LBNP. In conclusion, the lack of MSNA adjustment to a larger drop in arterial blood pressure during progressive LBNP, coupled with altered sympathetic burst latency responses, suggests that alcohol blunts MSNA responses to orthostatic stress.     

CIRCADIAN PATTERN OF BLOOD PRESSURE,HEART RATE,AND DOUBLE PRODUCT IN LIVER GLYCOGEN STORAGE DISEASE

The objective of this study was to determine systolic, diastolic, and mean arterial blood pressure (SBP, DBP, and MAP), heart rate (HR), double-product (DP: SBP×HR), and activity levels and their 24h pattern in liver glycogen storage disease (LGSD) patients. A case series of 12 (11 pediatric and one adult) diurnally active LGSD (seven type I, three type III, and two type IX) subjects were simultaneously assessed by 24h ambulatory blood pressure monitoring and wrist actigraphy. Nine subjects were judged to be hypertensive based on the criterion of an elevated 24h mean SBP and/or DBP being elevated beyond reference standards or the SBP and/or DBP load (percentage of time BP exceeds normal values) being greater than 25%. Two of the three other subjects, not viewed as hypertensive based on their 24h average SBP or DBP, exhibited daytime or nighttime SBP and/or DBP load hypertension. Each study variables displayed statistically significant (p<0.001) group circadian rhythmicity. The SBP, DBP, and MAP displayed comparable 24h patterns of appreciable amplitude (total peak–trough variation equal to 17.7, 23.6, and 19.6%, respectively, of the 24h mean) with highest values (orthophase) occurring ～11 h after the commencement of daytime activity. The sleep-time trough (bathyphase) occurred ～4.5 h before morning awakening. The statistically significant (p<0.006) circadian rhythms of HR (amplitude equal to 33.2% of the 24h mean) and DP (amplitude equal to 49.4% of the 24h mean) peaked earlier, ～7.4 h into the daytime activity span. The sleep-time trough occurred ～3 h before morning awakening. The 24h pattern in the cardiovascular variables was correlated with the 24h pattern of activity, with r ranging from 0.50 for DBP to 0.39 for HR.     

Relationship between Blood Pressure and Outcomes in Acute Ischemic Stroke Patients Administered Lytic Medication in the TIMS-China Study

Objective

Increased blood pressure (BP) management following acute ischemic stroke (AIS) remains controversial. This study aimed to identify the association between BP and clinical outcomes in AIS patients administered lytic medication in the TIMS-China (thrombolysis implementation and monitor of acute ischemic stroke in China) database.

Methods

The sample comprised 1128 patients hospitalized within 4.5 hours (h) of AIS for intravenous recombinant tissue plasminogen activator (i.v. rt-PA) thrombolysis. Systolic BP (SBP) and diastolic BP (DBP) at baseline, 2 h and 24 h after treatment, and changes from baseline were analyzed. The study outcomes comprised a favorable outcome (modified Rankin Scale 0–1 at 90 days) and symptomatic intracerebral hemorrhage (SICH), analyzed using logistic regression, with low BP as the reference group.

Results

Lower BP (baseline, 2 h, and 24 h) was beneficial in AIS patients and significantly related to a favorable outcome (P<0.05). A substantial BP decrease at 24 h after rt-PA thrombolysis was significantly associated with a favorable outcome compared with a moderate BP decrease (P = 0.0298). A SBP >160 mmHg 2 h after rt-PA thrombolysis was significantly associated with SICH compared with a SBP <140 mmHg (P = 0.0238). An increase or no change (>25 mmHg) in SBP was significantly associated with SICH (P = 0.002) compared with a small SBP decrease (1–9 mmHg).

Conclusions

This study provides novel evidence that lower BP within the first 24 h is associated with a more favorable outcome and less frequent SICH in AIS patients administered lytic medication. Routine BP-lowering treatment should be considered in AIS patients following lytic medication.     

Non-invasive blood pressure measurement in Yucatan miniature swine using tail cuff sphygmomanometry

A relatively new non-invasive method using a photo-electric flow sensor in non-heated animals, was evaluated for its accuracy in measuring systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) in 40-90 Kg normotensive and hypertensive Yucatan miniature swine. Directly measured SBP, DBP and electronically averaged MAP were recorded from chronic arterial catheters simultaneously with indirect pressures, cuff pressure and tail blood flow under various conditions. In all of the tests tail cuff SBP estimation averaged within 5% of directly measured SBP. The correlation of the two methods was significant (r = .95, P less than 0.01). Over a 60 to 202 mmHg range of blood pressure induced pharmacologically or due to DOCA hypertension, the tail cuff SBP was within 4-10% of directly measured SBP. The tail cuff method was also used to determine DBP and MAP. DBP determined from the tail cuff record was found consistently to underestimate the direct measured DBP by approximately 17%. The two methods were correlated (r = .87 P less than 0.01). The measured tail cuff MAP generally underestimated the direct MAP by approximately 5%. The correlation of directly measured MAP and tail cuff methods was significant (r = .72, P less than 0.01). These results indicated that this system may be used to accurately assess blood pressure in miniature swine.     

Effect of tomato,lycopene and related products on blood pressure: A systematic review and network meta-analysis

BackgroundA number of randomized controlled trials (RCTs) have been conducted to evaluate the hypotensive effects of tomato, lycopene, and related products. However, the findings were conflicting, partly due to differences in the types of products investigated. Therefore, this study aimed to assess and compare the hypotensive effects of different tomato-related preparations through a network meta-analysis based on randomized controlled trials.Study designA systematic review and network meta-analysis.MethodsA network meta-analysis based on a systematic review of RCTs comparing the effect of various tomato, lycopene and related products versus placebo on blood pressure in adults was performed. PubMed, EMBASE, SCOPUS, and Clinicaltrial.gov databases were searched up to October 2020 without language restrictions. The primary outcomes were systolic and diastolic blood pressure. Mean differences (MDs) along with 95% confidence intervals (CIs) were estimated and pooled using a random-effects model. Heterogeneity was assessed using the global inconsistency test.ResultsA total of 11 studies including six forms of tomato, lycopene and related products met the inclusion criteria. Among these trials, eight (N = 617) and seven trials (N = 501) were included in the analysis of systolic (SBP) and diastolic blood pressure (DBP) outcomes, respectively. The standardized tomato extract (STE) significantly decreased SBP compared to placebo, with a pooled MD (95% CI) of –5.89 (–9.13 to –2.64) mmHg. The effect on DBP was not significant, with a pooled MD (95% CI) of –3.51 (–7.39 to 0.38) mmHg. Subgroup analysis in hypertensive patients showed that STE significantly reduced both SBP and DBP with pooled MDs (95% CIs) of –8.09 (–11.52 to –4.67) and –4.25 (–6.97 to –1.53) mmHg, respectively, compared to placebo. Other forms of tomato, including other dose ranges of standardized tomato extract, tomato-containing diet, lycopene-free preparation, and synthetic lycopene, did not show consistent and significant effects on either SBP or DBP in all analyses.ConclusionStandardized tomato extract (STE) significantly decreased SBP compared to placebo in a mixed population of healthy volunteers and hypertensive patients. The BP-lowering effect was more pronounced among hypertensive patients. No significant BP effects were seen with other forms of tomato, lycopene and related products in the overall population or any subgroup of the population.     

高血压大鼠心肌肥大及逆转过程中相关因素的探讨

目的：探讨在心肌肥大及逆转过程中收缩压(SBP)、舒张压(DBP)、平均动脉压(MAP)、神经肽Y(NPY)等与左心室肥大的关系。方法：血压和心率用生物信号分析系统记录;NPY用放射免疫法测定,用SPSS软件求出了相关系数和回归方程。结果：SBP、DBP、MAP、心肌匀浆中NPY与心系数(LVW／BW)呈正相关,血液中NPY和心率(HR)与心系数不相关。结论：血压升高是导致左室肥大的因素之一,收缩压的影响大于舒张压;SBP、DBP、MAP、心肌匀浆中NPY与心系数(LVW/BW)有相关的趋势。     

血液透析血压及其变异性与患者预后的相关性分析

目的:探讨血液透析前后和血液透析过程中血压及其变异性与患者预后的相关性。方法:选取沈阳军区总医院血液透析中心2010年1月1日至2013年12月31日收治的维持性血液透析患者,收集并对比随访期内生存及死亡患者的自然信息及临床资料,评估血液透析过程中患者血压及其变异程度与患者预后的关系。结果:共有269例患者纳入研究,经过4年随访共死亡83(30.86%)例。死亡组年龄显著大于存活组(64.92±13.24岁比49.89±12.86岁,P=0.000),而透析年限显著短于存活组(2.60±2.56年比7.25±4.14年,P=0.000)。死亡组透析前SBP(P=0.001)、DBP(P=0.000)、MAP(P=0.000)均显著高于存活组。两组间透析后SBP、DBP、MAP比较均无显著差异。死亡组△SBP(P=0.026)、△DBP(P=0.001)、△MAP(P=0.001)幅度显著大于存活组。死亡组透析前SBP变异率显著高于存活组(P=0.001);死亡组透析后SBP变异率(P=0.000)、DBP变异率(P=0.014)、MAP变异率(P=0.005)均高于存活组。死亡组每次透析前各时间点间SBP变异率(0.12±0.04 mm Hg比0.09±0.03 mm Hg,P=0.000)与MAP变异率(0.10±0.03mm Hg比0.09±0.03 mm Hg,P=0.001)显著高于非死亡组。结论:维持性血液透析患者透析前血压、透析前后血压改变幅度、透析前后血压变异率、每次透析各时间点间血压变异率等与全因死亡相关。     

The influence of endurance training on the transient haemodynamic response to orthostatic manoeuvre.

Several investigations demonstrated that aerobic fitness is associated with a tendency towards orthostatic hypotension whereas other reports did not show any differences in cardiovascular adjustment to orthostatic challenges between endurance trained and sedentary subjects. In the present work, the time course of changes in heart rate (HR), systolic time intervals (STI), stroke volume (SV), cardiac output (CO) and blood pressure was studied during 8 minutes following standing up from supine position in 7 healthy volunteers before and after 10 weeks of endurance training on bicycle ergometer. Impedance cardiography was used for measurement of cardiac postural responses. The training program applied in this study increased the subjects' aerobic capacity (VO2max) by approx. 18%. After training, the steady-state supine HR and contribution of the pre-ejection period and ejection time to the total R-R interval in ECG were lowered while SV was significantly increased. No significant training-induced changes were found in magnitude and time-courses of HR, STI, SV and CO changes following standing up. Diastolic blood pressure during standing was greater after than before training. It is concluded that the short-time endurance training does not affect adversely cardiovascular orthostatic response and may even improve orthostatic tolerance due to the augmentation of diastolic blood pressure response.     

Validity of auscultatory and Penaz blood pressure measurements during profound heat stress alone and with an orthostatic challenge

Despite frequent reporting of blood pressure (BP) during profound passive heat stress, both with and without a hypotensive challenge, the method by which BP is measured often varies between laboratories. It is unknown whether auscultatory and finger BP measures accurately reflect intra-arterial BP during dynamic changes in cardiac output and peripheral resistance associated with the aforementioned conditions. The purpose of this investigation was to test the hypothesis that auscultatory BP measured at the brachial artery, and finger BP measured by the Penaz method, are valid measures of intra-arterial BP during a passive heat stress and a heat-stressed orthostatic challenge, via lower body negative pressure (LBNP). Absolute (specific aim 1) and the change in (specific aim 2) systolic (SBP), diastolic (DBP), and mean BPs (MBP) were compared at normothermia, after a core temperature increase of 1.47 ± 0.09°C, and during subsequent LBNP. Heat stress did not change auscultatory SBP (6 ± 11 mmHg; P = 0.16), but Penaz SBP (-22 ± 16 mmHg; P < 0.001) and intra-arterial SBP (-11 ± 13 mmHg P = 0.017) decreased. In contrast, DBP and MBP did not differ between methods throughout heat stress. Compared with BP before LBNP, the magnitude of the reduction in BP with all three methods was similar throughout LBNP (P > 0.05). In conclusion, auscultatory SBP and Penaz SBP failed to track the decrease in intra-arterial SBP that occurred during the profound heat stress, while decreases in arterial BP during an orthostatic challenge are comparable between methodologies.     

急救中光棒法与直接喉镜法气管插管引发心血管反应的比较

目的:比较光棒法与直接喉镜法气管插管对心血管系统的影响,探讨光棒在临床急救领域的适用性。方法:选取我院急诊科室进行抢救的80名患者,随机分为两组,分别采用光棒法和直接喉镜法进行气管插管。记录插管所需时间、一次插管成功次数,以及插管前、插管时、插管后1分钟、插管后3分钟患者的收缩压、舒张压、平均动脉压、心率和血氧饱和度的变化情况。数据分析使用使用检验、t检验秩和检验、重复测量方差分析。结果:两组间性别、年龄、身高、体重、ASA、Mallampati评分差异无统计学意义,具备可比性。光棒组平均插管时间少于喉镜组(光棒:31.23 9.94秒,喉镜:48.15 8.67秒),一次插管成功率(97.5%)也高于喉镜组(80.0%)。经重复测量方差分析结果显示,光棒组各时点的收缩压(F=38.312,P=0.000)、舒张压(F=219.692,P=0.000)、平均动脉压(F=54.739,P=0.000)、心率(F=195.161,P=0.000)的整体趋势要低于与喉镜组。血氧饱和度(F=0.020,P=0.889)在两组间差异无统计学意义。结论:在气管插管过程中,光棒法比直接喉镜法引发的心血管系统变化更小,而且插管所需时间更短、一次成功率更高,是一种值得在急诊科室推广的气管插管技术。     

Blood pressure and heart rate effects, weight loss and maintenance during long-term phentermine pharmacotherapy for obesity

There is a perception that phentermine pharmacotherapy for obesity increases blood pressure and heart rate (HR), exposing treated patients to increased cardiovascular risk. We collected data from phentermine‐treated (PT) and phentermine‐untreated (P0) patients at a private weight management practice, to examine blood pressure, HR, and weight changes. Records of 300 sequential returning patients were selected who had been treated with a low‐carbohydrate ketogenic diet if their records included complete weight, blood pressure, and HR data from seven office examinations during the first 12 weeks of therapy. The mean time in therapy, time range, and mode was 92 (97.0), 12–624, and 52 weeks. 14% were normotensive, 52% were prehypertensive, and 34% were hypertensive at their first visit or had a previous diagnosis of hypertension. PT subjects systolic blood pressure/diastolic blood pressure (SBP/DBP) declined from baseline at all data points (SBP/DBP ?6.9/?5.0 mm Hg at 26, and ?7.3/?5.4 at 52 weeks). P0 subjects' declines of SBP/DBP at both 26 and 52 weeks were ?8.9/?6.3 but the difference from the treated cohort was not significant. HR changes in treated/untreated subjects at weeks 26 (?0.9/?3.5) and 52 (+1.2/?3.6) were not significant. Weight loss was significantly greater in the PT cohort for week 1 through 104 (P = 0.0144). These data suggest phentermine treatment for obesity does not result in increased SBP, DBP, or HR, and that weight loss assisted with phentermine treatment is associated with favorable shifts in categorical blood pressure and retardation of progression to hypertension in obese patients.     

不同麻醉方法对二氧化碳气腹致应激激素和循环功能的影响

目的：观察比较全麻和全麻复合硬膜外麻醉在腹腔镜胆囊切除术（LC）时,对CO2气腹致应激激素和循环功能的影响。方法：40例LC患者随机分为全麻组（A组,n=20）和全麻复合硬膜外麻醉组（B组,n=20）,连续监测SBP、DBP、MAP、HR、ECG、SpO2、PETCO2,记录两组患者麻醉前（T1）、插管后（T2）、气腹后10min（T3）、气腹后20min（T4）和放气后10min（T5）的SBP、DBP、MAP、HR、同时抽静脉血测定血糖（Glu）、血浆皮质醇（Cor）、促肾上腺皮质激素（ACTH）和血管紧张素-Ⅱ（AT-Ⅱ）。结果：T1时两组所有检测值比较差异无显著性（P＆gt;0.05）;在T2、T3、T4、T5时A组SBP、DBP、MAP值明显升高,B组较基础值下降,组间差异显著（P＆lt;0.05）;气腹建立后A组HR,Glu、Cor、ACTH、AT-Ⅱ明显上升（P＆lt;0.05）,B组无显著变化（P＆gt;0.05）,（除ACTH外）组间差异显著（P＆lt;0.05）。结论：全麻复合硬膜外麻醉用于LC手术时,能相对更好的的抑制CO2气腹所致应激激素的升高,使循环更稳定。