Important Cardiovascular Parameters Research Articles

Physical training augmented with whole body electronic muscle stimulation favorably impacts cardiovascular biomarkers in healthy adults – A pilot randomized controlled trial

BackgroundPhysical activity is protective against cardiovascular disease (CVD) and favorably improves CVD risk profile. However, more than 25 % of American adults report no participation in physical activity. Whole body electronic muscle stimulation (WB-EMS) training is a novel FDA-cleared technology which offers a time-efficient and adaptable method for physical training by simultaneously stimulating the main muscle groups using percutaneous electrical impulse transmission. Studies have demonstrated increased muscle mass, reduced fat mass, and improved functional capacity in sedentary individuals after training with WB-EMS, but studies evaluating the role of WB-EMS training on CVD risk profile are lacking. MethodsWe performed a pilot randomized controlled trial in healthy adults randomized to physical training with versus without WB-EMS for one session of 20 min duration per week across 16-weeks. Study participants were asked to perform their usual activities but to abstain from any strength training during the study. During each training session, all study participants wore a specifically designed vest and arm and leg straps that were connected with electrical wires to the WB-EMS device (Miha Bodytec Gersthofen, Germany). Biphasic electrical stimulation was delivered through the vest and straps (4 s on, 4 s off) at a frequency that elicited a score of 5 or 6 on the Borg rating of perceived exertion scale from study participants when each of the following muscle groups was stimulated: thighs, buttocks, lower back, upper back, latissimus dorsi, abdomen, chest and arms. These frequencies were ‘titrated’ during the first 4 weeks and were then fixed at each muscle group for each participant. Individuals randomized to no WB-EMS wore the same equipment but received no electrical stimulation. Physical training sessions were provided by personal trainers certified for WB-EMS training and consisted of a fixed number of exercises and repetitions. We measured and compared several clinically important cardiovascular parameters at baseline and post-intervention. ResultsSeventy-eight participants were recruited between January 2021 and March 2022 with a mean age of 35.9 ± 11.2, 61.3 % females, median BMI 24.3 (21.8, 28.1); N = 46 were randomized to intervention group and N = 32 were randomized to the control group. Eighteen (23 %) participants dropped out of the trial, including 9 participants from the EMS arm (19.6 %), and 9 participants in control arm (28.1 %). There was no significant differences in the rate of dropping out of the WB-EMS and control groups (p = 0.27). Those in the intervention group compared to controls exhibited the following changes after 16-weeks of training: waist:hip ratio (∆ -0.03 ± 0.05, p = 0.01 vs. -0.01 ± 0.0, p = 0.1), peripheral endothelial function, measured using reactive hyperemia peripheral arterial tonometry (∆: 0.02 ± 0.1, p = 0.5 vs. -0.20 ± 0.3 p = 0.05), high-sensitivity C-reactive protein (∆: 0.06 ± 0.7, p = 0.3 vs. 0.20 ± 2.3 p = 0.02), total cholesterol (∆: −1.7 ± 25.1, p = 0.3 vs. 19.2 ± 26.5, p < 0.001), high density lipoprotein (∆: 2.02 ± 6.6, p = 0.2 vs. 3.6 ± 7.5 p = 0.01) and low density lipoprotein cholesterol (∆: 0.5 ± 26.7, p = 0.4 vs. 17.1 ± 23.2, p < 0.001). ConclusionOnce weekly physical training with WB-EMS in healthy adults resulted in either improved or stable biomarkers of cardiovascular risk, which either remained stable or worsened in those undergoing conventional training alone. Thus WB-EMS may provide an effective and time-efficient form of physical training that may be considered in those unable or unwilling to perform exercise conventionally.

A Wireless Communication Network With a Ballistocardiography Experiment on the ISS: Scenario, Components and Preflight Demonstration

This paper introduces Wireless Compose-2 (WICO2), which is an experiment for the International Space Station (ISS) in order to demonstrate the provision of a flexible and adaptable wireless network infrastructure integrated into a commodity item to conduct and execute low-power, low-weight and wireless experiments in the scientific and medical domain. Recent work revealed a great potential in utilizing Wireless Sensor Network (WSN) in space habitats; however, the focus was only placed on sensing in the narrowband Industrial Scientific and Medical (ISM) 2.45 GHz band. This work extends these capabilities by utilizing Impulse Radio Ultra Wideband (IR-UWB) for ranging and evaluates the use of internal light sources for energy harvesting to drive the sensor nodes. The focus of the WICO2 experiment is on the operation of the scientific experiment Ballistocardiography for Extraterrestrial Applications and long-Term missions (BEAT), which is a demonstration of novel Ballistocardiography (BCG) sensors to monitor important cardiovascular parameters in a microgravity environment. Integrated in a Smart-Shirt, it will form a Body Area Network and make use of the IR-UWB communication to transmit the data to the network. This paper describes the concept and pre-flight test results to demonstrate the correct function, usability and performance of WICO2.

Progressive Dynamic Time Warping for Noninvasive Blood Pressure Estimation

Abstract Arterial blood pressure is one of the most important cardiovascular parameters. Yet, current-generation devices for continuous, noninvasive acquisition are few, expensive and bulky. Novel signal processing applied to easily acquired unimodal signals can alleviate this issue, reducing size, cost and expanding the use of such devices to ambulatory, everyday settings. The features of pulse waves acquired by photo- or impedance-plethysmography can be used to estimate the underlying blood pressure. We present a progressive dynamic time warping algorithm, which implicitly parametrizes the morphological changes in these waves. This warping method is universally applicable to most pulse wave shapes, as it is largely independent of fiducial point detection or explicit parametrization. The algorithm performance is validated in a feature selection and regression framework against a continuous, noninvasive Finapres NOVA monitor, regarding systolic, mean and diastolic pressures during a light physical strain test protocol on four clinically healthy subjects (age18- 33, one female). The obtained mean error is 2.13 mmHg, the mean absolute error is 5.4 mmHg and the standard deviation is 5.6 mmHg. These results improve on our previous work on dynamic time warping. Using single-sensor, peripherally acquired pulse waves, progressive dynamic time warping can thus improve the flexibility of noninvasive, continuous blood pressure estimation.

Antihypertensive potential of linalool and linalool complexed with β-cyclodextrin: Effects of subchronic treatment on blood pressure and vascular reactivity

Linalool (LIN) is a monoterpene alcohol present in some aromatic medicinal plants with biological activities that can impact cardiovascular diseases. This chemical class is highly volatile and β-cyclodextrin (β-CD) has been employed to improve the pharmacological properties of monoterpenes. Thus, the aim of this study was to evaluate the cardiovascular effects of LIN free focusing on the antihypertensive properties of this monoterpene and to study whether LIN, complexed in β-cyclodextrin (LIN-βCD) is able to improve the pharmacological activity of LIN. Spontaneously hypertensive rats (SHR) were randomly divided into 5 groups, each treated daily for 21 days, in the following manner: group 1 (vehicle solution); group 2 (captopril; 30 mg/kg/day); group 3 (LIN; 100 mg/kg/day); group 4 (LIN; 50 mg/kg/day) and group 5 (LIN/β-CD; 50 mg/kg/day). Daily body weight measurements were conducted and mean arterial pressure and heart rate were measured every 5 days. The mesenteric artery from treated animals was tested for phenylephrine and sodium nitroprusside (SNP) sensitivity. The SHR treated with vehicle demonstrated progressive increase in mean arterial pressure and captopril, a positive control, induced a significant decrease. After 21 days of treatment, the blood pressure of the SHR treated by (−)-LIN (100 mg/kg) was significantly reduced. In addition, various important cardiovascular parameters improved, including: the treatment with LIN prevented the development of cardiac hypertrophy, increased levels of the anti-inflammatory cytokine (IL-10), increased vasodilator responsiveness and reduced sensitivity to the sympathetic agonist. Furthermore, the inclusion complex containing LIN in β-CD produced a higher antihypertensive profile when compared with uncomplexed form. Taking together, our results suggested that LIN shown a potential antihypertensive effect and β-CD may be an important tool to improve the cardiovascular activity of LIN and other water-insoluble compounds.

Cardiovascular determinants of prognosis in normotensive hemodialysis patients

BackgroundNormotension has been hold to be the goal of hemodialysis. It remains obscure which cardiovascular parameter determines the prognosis in these normotensive hemodialysis patients.MethodsWe prospectively enrolled 145 hemodialysis patients, who had attained normotension without anti-hypertensive medications, and followed them for 72.6 ± 28.5 months. Important cardiovascular parameters were obtained at enrollment. Predictors for all-cause and cardiovascular mortalities were identified with the Cox model.ResultsThere were 45 (18 cardiovascular/27 non-cardiovascular) deaths occurred during follow-up. Age, diabetes, left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), carotid intima-media thickness (CIMT), and aortic pulse wave velocity (PWV) were significant predictors for all-cause and cardiovascular mortalities. After adjustment for age and diabetes, only LVEF was significantly associated with all-cause mortality. LVEF was significantly associated with cardiovascular mortality. LVEF remained as a significant independent predictor of cardiovascular death after adjusting for age, diabetes, LVMI, CIMT, or PWV, respectively.ConclusionLVEF is the independent predictor for all-cause and cardiovascular mortalities in the normotensive hemodialysis patients.

Erythropoiesis Stimulating Agents in Heart Failure Patients with Anemia: A Meta-Analysis

Anemia is prevalent in patients with heart failure and an independent prognostic sign of poor outcome. The current report is a meta-analysis of published clinical trials assessing the use of erythropoeisis stimulating agents (ESA) in heart failure (HF) patients with anemia. Literature and Medline search was performed to identify studies with control groups (case-control, cohort or randomized controlled trials) that examined the effect of ESA therapy in patients with HF and anemia. Seven prospective controlled trials met inclusion criteria (n = 663 subjects). The ESA studied was darbepoetin in 4 trials and erythropoietin in 3 trials. Mean follow up period ranged from 12 to 27 weeks. Compared to placebo ESA therapy was associated with improvement in six cardiovascular parameters assessed by at least three of the analyzed trials, including increase in hemoglobin levels 2.35(95% confidence interval [Cl], 1.76-2.93, P < 0.00001), increase in exercise duration 0.91(95% Cl, 0.08-1.73, P = 0.03), improvement in New York Heart Association functional class -1.46(95% Cl, -2.32 to -0.60, P = 0.0009), improvement in 6-minute walk test 1.42(95% Cl, 0.31-2.54, P = 0.01), decrease in B-type natriuretic peptide -0.54(95% Cl, -1.03 to -0.06, P = 0.03), and improvement in peak oxygen consumption 0.93(95% Cl, 0.52-1.34, P < 0.00001). In patients with heart failure and anemia, erythropoiesis stimulating agent therapy appears to have a positive effect on several important cardiovascular parameters, compared to control therapy. Large prospective randomized controlled trials are warranted to comprehensively evaluate the potential effects of erythropoiesis stimulating agents on clinical outcomes in heart failure patients with anemia.

Identification of Cardiovascular Dilution Systems by Contrast Ultrasound

Indicator dilution techniques permit accurate measurements of important cardiovascular parameters, such as pulmonary blood volume (PBV) and ejection fraction (EF). However, their use is limited by the need for central catheterization. Contrast ultrasonography allows overcoming this problem. PBV and EF can be measured by a dilution system identification algorithm after detection of multiple dilution curves by an ultrasound scanner. In this paper, we present a system identification method that exploits the a priori knowledge on the dilution system and finds the optimum parameters for the parametric model representing the dilution system impulse response. No subsequent model interpolation is needed. Volume measurements show accurate in-vitro results and clinical feasibility, while 50 EF measurements in patients show a 0.88 correlation coefficient with echocardiographic biplane estimates. In conclusion, adding a priori knowledge to the system identification algorithm leads to increased accuracy and robustness of the method for PBV and EF measurements. (E-mail: m.mischi@tue.nl)

A model for evaluation of artificial oxygen carriers regarding circulation, respiration and metabolism in anesthetized spontaneously breathing guinea pigs.

The evaluation of artificial oxygen carriers requires experiments with suitable animals. Many investigators do this with the classical laboratory animal, the rat, but it has a quite different oxygen pressure of half saturation (p50 = 36 mmHg) from that of humans (26 mmHg). It was demonstrated that induced changes of the p50 value in animals provokes substantial changes in important cardiovascular parameters. Therefore, we decided to develop a guinea pig model for evaluation of artificial oxygen carriers, because it has a p50 of about 24 mmHg that is very similar to that of man. We found an anesthesia combination using fentanyl/droperidol/urethane to be very suitable for the narcosis, because important cardiovascular and respiratory parameters remain normal. Our model allows assessment of arterial pressure, oxygen uptake, carbon dioxide release, cardiac output, total peripheral resistance, shock index, blood lactate level, and, in particular, it allows to differentiate the oxygen transport in blood. We evaluated two hemoglobin-based oxygen carriers: bovine and porcine hemoglobin polymerized with glutaraldehyde in isoncotic solution (n = 3). Control experiments (n = 4) were done with an isotonic albumin solution. The protocol comprised a so-called exchange phase (I) with different degrees of hemodilution and a so-called time phase (II), an observation period with a hematocrit of 10% over about 3 hours. In the control group substantial changes in mean arterial pressure, total peripheral resistance, shock index, oxygen uptake and of blood lactate level were seen. All these effects were prevented by the artificial oxygen carriers tested. The carriers proved to be very effective, as small quantities in blood effectively restored these parameters, presumably via synergetic effects. Moreover, the experiments clearly revealed the limitation of hemodilution, at least in guinea pigs: below a hematocrit of 20% all parameters mentioned above changed significantly. The animal model presented proved to be appropriate for the evaluation of artificial oxygen carriers.

Enhancement of Specific Biological Activity of Dipyridamole by Complexation with &amp;beta;-Cyclodextrin

Dipyridamole forms an inclusion complex with beta-cyclodextrin (dip-beta-CD) which shows better solubility and bioavailability than the uncomplexed compound. The present studies have demonstrated that dip-beta-CD is more effective than dipyridamole either as base or HCl (dispersed or not in lactose) on some important cardiovascular parameters when orally administered to conscious animals. In particular, dip-beta-CD causes a stronger and prompter coronary and carotid vasodilatation in dogs, at doses which weakly influence the systemic arterial pressure and the heart rate. In addition, platelets collected from treated rabbits at various intervals appear to be protected from sodium adenosine diphosphate-induced aggregation in vitro more effectively and rapidly by dip-beta-CD than by dipyridamole. Studies on tail bleeding time have confirmed that dip-beta-CD is more active than dipyridamole when given orally to mice. These biological findings are fully in agreement with other oral bioavailability studies in dogs and men indicating that dip-beta-CD gives quicker and higher blood levels with smaller interindividual variability than dipyridamole.