Cardiac Output Values Research Articles

Normal Values of Cardiac Output and Stroke Volume According to Measurement Technique, Age, Sex, and Ethnicity: Results of the World Alliance of Societies of Echocardiography Study

Assessment of cardiac output (CO) and stroke volume (SV) is essential to understand cardiac function and hemodynamics. These parameters can be examined using three echocardiographic techniques (pulsed-wave Doppler, two-dimensional [2D], and three-dimensional [3D]). Whether these methods can be used interchangeably is unclear. The influence of age, sex, and ethnicity on CO and SV has also not been examined in depth. In this report from the World Alliance of Societies of Echocardiography Normal Values Study, the authors compare CO and SV in healthy adults according to age, sex, ethnicity, and measurement techniques. A total of 1,450 adult subjects (53% men) free of heart, lung, and kidney disease were prospectively enrolled in 15 countries, with even distributions among age groups and sex. Subjects were divided into three age groups (young, 18-40years; middle aged, 41-65years; and old, >65years) and three main racial groups (whites, blacks, and Asians). CO and SV were indexed (cardiac index [CI] and SV index [SVI], respectively) to body surface area and height and measured using three echocardiographic methods: Doppler, 2D, and 3D. Images were analyzed at two core laboratories (one each for 2D and 3D). CI and SVI were significantly lower by 2D compared with both Doppler and 3D methods in both sexes. SVI was significantly lower in women than men by all three methods, while CI differed only by 2D. SVI decreased with aging by all three techniques, whereas CI declined only with 2D and 3D. CO and SV were smallest in Asians and largest in whites, and the differences persisted after normalization for body surface area. The present results provide normal reference values for CO and SV, which differ by age, sex, and race. Furthermore, CI and SVI measurements by the different echocardiographic techniques are not interchangeable. All these factors need to be taken into account when evaluating cardiac function and hemodynamics in individual patients.

Acupuncture combined with western medication in treatment of type 2 diabetes mellitus with angina pectoris of coronary heart disease: a randomized controlled study

To compare the therapeutic effect on type 2 diabetes mellitus (T2DM) complicated with angina pectoris of coronary heart disease between the combined therapy of acupuncture and western medication and the simple administration of western medication. A total of 134 patients with T2DM and angina pectoris of coronary heart disease were randomly divided into two groups, i.e. an acupuncture plus medication group (67 cases, 3 cases dropped off) and a medication group (67 cases, 4 cases dropped off). The routine western medication was used according to symptoms in the patients of both groups. In the acupuncture plus medication group, on the base of medication, acupuncture was applied to Jianshi (PC 5), Quchi (LI 11), Neiguan (PC 6), etc. The needles were retained for 20 min in each treatment and 3 treatments of acupuncture were required weekly. The treatment was given consecutively for 8 weeks in the two groups. Separately, before and after treatment, the symptom scores of TCM were observed and the indexes were detected, including glycolipid metabolism [fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), glucosylated hemoglobin (HbA1c), triacylglycerol (TG) and total cholesterol (TC)], islet β cell function [homeostasis model assessment-β (HOMA-β), homeostasis model assessment-IR (HOMA-IR), fasting insulin (FINS) and insulin sensitivity index (ISI)], cardiac function indexes [cardiac output (CO), early diastolic peak velocity/late diastolic peak velocity (E/A), left ventricular end diastolic diameter (LVEDD) and left ventricular ejection fraction (LVEF)], as well as electrocardiogram QT dispersion (QTd). Besides, the clinical therapeutic effects were compared between the two groups. After treatment, the TCM symptom scores and the values of FPG, 2hPG, HbA1c, TG, TC, HOMA-IR, FINS, E/A and LVEDD as well as QTd were all lower than those before treatment in the two groups (P<0.05), and the levels of the above-mentioned indexes in the acupuncture plus medication group were all lower than those in the medication group (P<0.05). The values of HOMA-β, ISI, CO and LVEF after treatment were higher than those before treatment in the two groups (P<0.05), and the levels of the above-mentioned indexes in the acupuncture plus medication group were all higher than those in the medication group (P<0.05). The total effective rate was 93.8% (60/64) in the acupuncture plus medication group, higher than 79.4% (50/63) in the medication group (P<0.05). The combined therapy of acupuncture and medication is effective in treatment of T2DM complicated with angina pectoris of coronary heart disease. Such therapy effectively improves glucolipid metabolism, islet β cell function, cardiac function and myocardial blood supply. Its curative effect is better than the simple administration of western medicine.

Quantification of Recirculation During Veno-Venous Extracorporeal Membrane Oxygenation: In Vitro Evaluation of a Thermodilution Technique.

Veno-venous extracorporeal membrane oxygenation (vv-ECMO) represents one of the most advanced respiratory support for patients suffering from severe acute respiratory distress syndrome. During vv-ECMO a certain amount of extracorporeal oxygenated blood can flow back from the reinfusion into the drainage cannula without delivering oxygen to the patient. Detection and quantification of this dynamic phenomenon, defined recirculation, are critical to optimize the ECMO efficiency. Our study aimed to measure the recirculation fraction (RF) using a thermodilution technique. We built an in vitro circuit to simulate patients undergoing vv-ECMO (ECMO flow: 1.5, 3, and 4.5 L/min) with different cardiac output, using a recirculation bridge to achieve several known RFs (from 0% to 50%). The RF, computed as the ratio of the area under temperature-time curves (AUC) of the drainage and reinfusion, was significantly related to the set RF (AUC ratio (%) = 0.979 × RF (%) + 0.277%, p < 0.0001), but it was not dependent on tested ECMO and cardiac output values. A Bland-Altman analysis showed an AUC ratio bias (precision) of -0.21% for the overall data. Test-retest reliability showed an intraclass correlation coefficient of 0.993. This study proved the technical feasibility and computation validity of the applied thermodilution technique in computing vv-ECMO RF.

Reduced exercise capacity in patients with systemic sclerosis is associated with lower peak tissue oxygen extraction: a cardiovascular magnetic resonance-augmented cardiopulmonary exercise study

BackgroundExercise intolerance in systemic sclerosis (SSc) is typically attributed to cardiopulmonary limitations. However, problems with skeletal muscle oxygen extraction have not been fully investigated. This study used cardiovascular magnetic resonance (CMR)-augmented cardiopulmonary exercise testing (CMR-CPET) to simultaneously measure oxygen consumption and cardiac output. This allowed calculation of arteriovenous oxygen content gradient, a recognized marker of oxygen extraction. We performed CMR-CPET in 4 groups: systemic sclerosis (SSc); systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH); non-connective tissue disease pulmonary hypertension (NC-PAH); and healthy controls.MethodsWe performed CMR-CPET in 60 subjects (15 in each group) using a supine ergometer following a ramped exercise protocol until exhaustion. Values for oxygen consumption, cardiac output and oxygen content gradient, as well as ventricular volumes, were obtained at rest and peak-exercise for all subjects. In addition, T1 and T2 maps were acquired at rest, and the most recent clinical measures (hemoglobin, lung function, 6-min walk, cardiac and catheterization) were collected.ResultsAll patient groups had reduced peak oxygen consumption compared to healthy controls (p < 0.022). The SSc and SSc-PAH groups had reduced peak oxygen content gradient compared to healthy controls (p < 0.03). Conversely, the SSc-PAH and NC-PH patients had reduced peak cardiac output compared to healthy controls and SSc patients (p < 0.006). Higher hemoglobin was associated with higher peak oxygen content gradient (p = 0.025) and higher myocardial T1 was associated with lower peak stroke volume (p = 0.011).ConclusionsReduced peak oxygen consumption in SSc patients is predominantly driven by reduced oxygen content gradient and in SSc-PAH patients this was amplified by reduced peak cardiac output.Trial registration The study is registered with ClinicalTrials.gov Protocol Registration and Results System (ClinicalTrials.gov ID: 100358).

Maternal hemodynamic assessment by USCOM® device in the first trimester of pregnancy

Background Preeclampsia is a main obstetric disease and could be caused by the inability of the woman hemodynamic system to face the cardiovascular effort required by gestation. Objective The aim of the present study is to evaluate the correlation between maternal hemodynamic parameters detected by UltraSonic Cardiac Output Monitor (USCOM®) and ultrasound or biochemical parameters in women during the first-trimester screening of chromosomal abnormalities. Methods This was a prospective observational study with 162 women enrolled during the first-trimester ultrasound, recording demographic, biochemical and ultrasound data, including the pulsatility index of uterine arteries (UTPI). Hemodynamic indices were obtained using the USCOM® system. We also analyzed the outcomes of pregnancy of those women who delivered in our clinic. Results As for the correlation between biochemical and ultrasound parameters, pregnancy-associated plasma protein A (PAPP-A) relates inversely with the mean UTPI (r s −0.298, p < .001). We also reported a statistically significant correlation between the mean UTPI and the maternal haemodynamic parameters detected by USCOM® (higher values of mean UTPI are associated with lower values of indexed cardiac output, CO, and higher indexed peripheral resistances, TVR). When comparing women with higher UTPI and TVR or lower CO to patients who had regular values of these parameters, we noticed that between these groups there were significant differences in all the remaining hemodynamic parameters, including inotropy index and stroke volume, as well as in the biochemical values of PAPP-A. Analyzing postpartum data, if we combine the onset of hypertensive disorders and fetal growth restriction, the most predictive parameter is indexed TVR. Conclusion Our study confirmed the correlation between PAPP-A and placental function, expressed through the determination of the pulsatility index of the uterine arteries. Moreover, we found a clear correlation between biochemical markers, placental function and maternal hemodynamics, since the first trimester of pregnancy. The inclusion of maternal hemodynamic evaluation could be useful in the screening protocols of preeclampsia. If we combine the onset of hypertensive disorders and of fetal growth restriction, the most predictive parameter is indexed total vascular resistances.

376 Maternal age impact on hemodynamic monitoring at delivery evaluated by a novel non-invasive PPG-based sensor

Age influence maternal hemodynamics and adaptation during labor and delivery. We utilized an innovative, noninvasive, reflective PPG-based device (Biobeat Technologies Ltd.) that enables continuous monitoring to assess cardiovascular changes during labor and delivery stratified by maternal age. The Biobeat Monitoring Platform includes a wearable wristwatch monitor, that automatically samples cardiac output (CO), blood pressure (BP), stroke volume (SV), systemic vascular resistance (SVR) and heart rate (HR) every 5 seconds and uploads all data to a smartphone-based app and to a data cloud, enabling remote monitoring and analysis of data. Low risk parturients carrying term, singletons pregnancies were recruited at early delivery. Big data analysis was performed using the Power BI analysis tool (Microsoft). Data was normalized to visual presentation using Excel Data Analysis and regression tool. Average measurements were compared 20 minutes before and after epidural anesthesia and fetal delivery, stratified by maternal age. 81 parturients were recruited (26 nullipara; BMI 29.7±5.1,Kg/m2) and allocated to study (≥ 35 years, 17/81, 21%, mean age 36.7±2) and control group (<35 years, 64/81, 79%, mean age 28.6±3.2). Over 800,000 measurements were retrieved. During labor and around epidural anesthesia study group had lower CO, SV and HR values. MAP was also lower despite higher SVR values (for example: mean CO 5.1 to 5 for study group vs. 5.5 to 5.6 for control group, L/min, 20 minutes before and after epidural, p<0.05 for all, Fig 1). Same trend continued at delivery with lower CO, HR, SVR, MAP and higher SVR values for study group (for example: mean CO 5.9 to 6.8 to 5.8 for study group vs. mean CO 6.1 to 7.3 to 6.5 for control group, L/min, 20 minutes before, at peak and after delivery, p<0.05 for all, Fig 2). Both epidural and delivery were associated with statistical significant changes for most parameters, however, not all differences had clinical significance. Maternal age influences hemodynamic adaptation during labor and delivery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Age-Specific Features of the Functional Development of the Circulatory System in Children Living in Northeastern Russia

Summary. Introduction: The problem of human interaction with the environment acquires special importance nowadays. Significant migration processes observed in the last decade have become global, thus necessitating studies of the mechanisms of human adaptation to new environmental conditions. Our objective was to study age-related changes in functional indices of the cardiovascular system in adolescents between 11 and 17 years of age, born in Magadan in the first to third generation of Caucasians who had migrated to this city. Material and methods: In all, 1,442 school-age adolescents were examined including 809 boys and 633 girls. The main anthropometric parameters (body weight, kg, and height, cm) were measured and cardiac hemodynamics was determined at rest in the sitting position by volumetric compression oscillometry using a non-invasive hard- and software unit for central hemodynamic study. Results: Significantly higher values of cardiac output and stroke volume prevailed in boys of all age groups. The boys aged 14-17 years also demonstrated higher values of systolic blood pressure and left ventricular power output compared to girls. At the same time, the girls had higher age-specific indices of the heart rate, diastolic blood pressure, and total peripheral resistance. Conclusion: We established that the highest rates of cardiovascular functional development occur during puberty in 11 to 16-year-old boys and 11 to 13-year-old girls. Our findings showed that only 70.2 % to 77.2 % of the boys and 75.1 % to 80.2 % of the girls had blood pressure and heart rate readings within the age norm. Prehypertension was registered in 11.3 % and 10.3 % while hypertension was observed in 11.5 % and 9.5 % of the examined boys and girls, respectively. Tachycardia at rest was noted in 18 % of the boys and 20.2 % of the girls.

Т1 mapping in the evaluation of the risk factors for diffuse myocardial fibrosis in essential arterial hypertension

Background : The assessment of diffuse myocardial fibrosis is necessary to plan the management of patients with various cardiovascular disorders, including hypertensive heart disease. The development of imaging techniques has enabled a non-invasive detection of left ventricular myocardial fibrosis by magnetic resonance imaging (MRI) with T1 mapping. Aim: By cardiac MRI, to identify risk factors for diffuse left ventricular myocardial fibrosis in patients with hypertensive heart disease. Materials and methods : This was a cross-sectional observational study in 50 outpatients with hypertensive heart disease, aged 46 to 82 years (median, 68 [64; 72] years) and bodyweight of 52 to 120 kg (median, 91 [80; 98] kg). Standard cardiac MRI with delayed contrast enhancement was performed with Optima MR450w GEM 1.5T (General Electric, USA). For assessment of diffuse myocardial fibrosis MRI mapping by 2D MOLLI (3-3-5) technique was used. The results were analyzed with Cvi42 software (Circle Cardiovascular Imaging Inc., USA). The potential risk factors included patients’ age, gender, bodyweight, and diastolic heart failure. Results: The mean time of T1 relaxation without contrast enhancement was 1122.64 ±63.67 ms, indicating the presence of myocardial fibrosis in 100% of the patients. Female patients had more advanced diffuse myocardial abnormalities (p &lt; 0.001). In the elderly patients, there was a direct correlation between their age and degree of fibrosis (p = 0.006). There was an inverse correlation between higher bodyweight and increased extracellular volume. Heart rhythm disorders and diastolic heart failure had no impact on the changes in the mapping parameters of the left ventricular myocardium and MRI-assessed cardiac output values. No correlation between the myocardial fibrosis and dyslipidemia/hyperlipidemia was found. There was a direct correlation between the native T1 mapping values and extracellular volume fraction (p = 0.004) and an inverse correlation between low values of post-contrast T1 mapping and increased extracellular volume fraction (p = 0.05). Conclusion: Т1 mapping in patients with essential arterial hypertension allows for detection of diffuse myocardial fibrosis of the left ventricle, which is recognised as a major indicator of myocardial remodeling. Female gender, older age, and bodyweight were the factors associated with more advanced myocardial fibrosis.

Can bioimpedance cardiography assess hemodynamic response to passive leg raising in critically ill patients: A STROBE-compliant study.

Passive leg raising (PLR) is a convenient and reliable test to predict fluid responsiveness. The ability of thoracic electrical bioimpedance cardiography (TEB) to monitor changes of cardiac output (CO) during PLR is unknown.In the present study, we measured CO in 61 patients with shock or dyspnea by TEB and transthoracic echocardiography (TTE) during PLR procedure. Positive PLR responsiveness was defined as the velocity-time integral (VTI) ≥10% after PLR. TTE measured VTI in the left ventricular output tract. The predictive value of TEB parameters in PLR responders was tested. Furthermore, the agreement of absolute CO values between TEB and TTE measurements was assessed.Among the 61 patients, there were 28 PLR-responders and 33 non-responders. Twenty-seven patients were diagnosed with shock and 34 patients with dyspnea, with 55.6% (15/27) and 54.6% (18/34) non-responders, respectively. A change in TEB measured CO (ΔCO) ≥9.8% predicted PLR responders with 75.0% sensitivity and 78.8% specificity, the area under the receiver operating characteristic curve (AUROC) was 0.79. The Δd2Z/dt2 (a secondary derivative of the impedance wave) showed the best predictive value with AUROC of 0.90, the optimal cut point was −7.1% with 85.7% sensitivity and 87.9% specificity. Bias between TEB and TTE measured CO was 0.12 L/min, and the percentage error was 65.8%.TEB parameters had promising performance in predicting PLR responders, and the Δd2Z/dt2 had the best predictive value. The CO values measured by TEB were not interchangeable with TTE in critically ill settings.

Physiological parameter values for physiologically based pharmacokinetic models in food-producing animals. Part II: Chicken and turkey.

Physiologically based pharmacokinetic (PBPK) models are growing in popularity due to human food safety concerns and for estimating drug residue distribution and estimating withdrawal intervals for veterinary products originating from livestock species. This paper focuses on the physiological and anatomical data, including cardiac output, organ weight, and blood flow values, needed for PBPK modeling applications for avian species commonly consumed in the poultry market. Experimental and field studies from 1940 to 2019 for broiler chickens (1–70 days old, 40 g ‐ 3.2 kg), laying hens (4–15 months old, 1.1–2.0 kg), and turkeys (1 day−14 months old, 60 g −12.7 kg) were searched systematically using PubMed, Google Scholar, ProQuest, and ScienceDirect for data collection in 2019 and 2020. Relevant data were extracted from the literature with mean and standard deviation (SD) being calculated and compiled in tables of relative organ weights (% of body weight) and relative blood flows (% of cardiac output). Trends of organ or tissue weight growth during different life stages were calculated when sufficient data were available. These compiled data sets facilitate future PBPK model development and applications, especially in estimating chemical residue concentrations in edible tissues to calculate food safety withdrawal intervals for poultry.

Normative Reference Values of Cardiac Output by Pulsed-Wave Doppler Echocardiography in Adults

Cardiac output (CO) is routinely assessed by pulsed-wave Doppler echocardiography, yet reference values in adults are lacking. We aim to establish normative values of CO and cardiac index (CI) by pulsed-wave Doppler-echocardiography and to analyze their relation with gender and age in nonobese and obese adults. We included 4,040 adults (mean age: 55 years, 53% women, 950 obese [body mass index ≥30 kg/m²]) with normal blood pressure, no history of cardiovascular disease, and normal transthoracic echocardiography. Normative reference CO and CI values for were calculated in 3,090 nonobese patients by quantile regression. CO normal limits were lower in females than in males (lower limit: 3.3 vs 3.5 L/min, upper limit: 7.3 vs 8.2 L/min). CI normal limits were identical for both genders (lower limit: 1.9 L/min/m², upper limit: 4.3 L/min/m²). Although the relation of CO to age was weak and observed only in women, CI of both genders was not influenced by age. CO of obese patients was significantly greater than that of their nonobese counterparts. CI of obese patients was not influenced by age and gender and was not significantly different than that of nonobese patients (lower limit 1.8 L/min/m², upper limit 4.1 L/min/m² for both genders). In conclusion, in a large adult population we establish normative reference values for CO and CI measured by Doppler-echocardiography. CI is a remarkably stable parameter that is not influenced by age, gender, and body size and should be used to define low- and high-output states.

Thermodilution vs indirect fick cardiac output measurement in clinical practice: insights from a tertiary centre

Abstract Introduction Thermodilution (TD) and indirect Fick (IF) methods are widely used to measure cardiac output (CO). They are often used interchangeably to make critical clinical decisions, yet few studies have compared these approaches concerning agreement and comparative prognostic value as applied in medical practice. Purpose To assess agreement between TD and IF methods and to compare how well these methods predict mortality. Methods Retrospective cohort study including all consecutive right heart catheterizations performed in a referral pulmonary hypertension (PH) centre from 2010 to 2018. Cardiac index (CI) was calculated by indexed CO to body surface area. PH was classified according to the new definition of the 6st World Symposium on Pulmonary Hypertension 2018 [mean pulmonary arterial pressure (mPAP) &amp;gt;20 mmHg]. Patients with cardiac or extra-cardiac shunts or significant (moderate to severe or severe) tricuspid regurgitation were excluded. All-cause mortality over 1 year after right heart catheterization was recorded. Logistic regression was used to identify predictors of the adverse event. Results From a total of 569 procedures, 424 fulfilled the inclusion criteria: mean age 56.7±15.4 years, 67.3% female. Haemodynamic parameters were diagnosed of PH in 86.2% of cases: mPAP 35.3±15.3 mmHg, 83.6% pre-capillary subtype, 42.9% belonging to group 4 (chronic thromboembolic pulmonary hypertension) and 26.6% to group 1 (pulmonary arterial hypertension). Mean values of CO and CI were, respectively, 4.5±2.8 L/min and 2.5±0.8 L/min/m2 measured by TD and 4.6±2.4 L/min and 2.6±1.3 L/min/m2 measured by IF method. There was a median difference (IF minus TD) of - 0.03 / min to CO and - 0.05 L/min/m2 to CI but both meausres correlated only modestly (r=0.6 to TD and r=0.5 to IF). One-year all-cause mortality rate was 5.4% (median time to death was 50.5 days). Lower values of CO and CI assessed by TD were significantly associated with all-cause mortality occurrence (CO TD: 4.5±1.3 L/min versus 3.6±1.0 L/min, p&amp;lt;0.01; CI TD: 2.6±0.7 L/min/m2 versus 2.1±0.4 L/min/m2, p&amp;lt;0.01). No association was observed between CO (p=0.31) and CI (p=0.42) measured by IF method and the adverse event. Logistic regression identified 2 independent predictors of all-cause mortality: TD CO (OR 0.55, 95% CI 0.38–0.79, p&amp;lt;0.01) and TD CI (OR 0.34, 95% CI 0.17–0.67, p&amp;lt;0.01). Similar results were obtained when patients diagnosed with PH were independently analyzed. Conclusions There is only modest agreement between TD and IF CO and CI estimates. Despite being more time-consuming, TD measurements were predictors of all-cause mortality and present a highest prognostic value. These findings favored their used over IF in clinical practice. Funding Acknowledgement Type of funding source: None

Comparative study between effects of single and dual chamber pacemaker on stroke volume, cardiac output and strain using 3D echocardiography, pulsed Doppler method and global longitudinal strain (GLS)

Abstract Background Dual-chamber cardiac pacing is thought to deliver higher clinical benefits as compared with single-chamber ventricular pacing. During the last two decades, 3D-echocardiography developed from a sophisticated, time-consuming method preferably used as a scientific tool towards a routine clinical approach. At present, available evidence suggested that 3D echocardiography provided improved accuracy and reproducibility over 2D methods for LV volume and function calculation. It was also more useful for early detection of volumetric changes associated with changes in cardiac hemodynamics. Methods This was an observational study of fifty consecutive patients without structural heart disease and preserved ejection fraction (EF&amp;gt;50%) presented with high grade atrioventricular block for permanent pacemaker implantation. They were assigned to receive a single-chamber ventricular pacemaker (23patients) or a dual-chamber pacemaker (27 patients). Stroke volume and cardiac output was assessed by full volume 3D echo and pulsed wave Doppler before implantation, at one-week and 6-months after implantation. For the Doppler method, LVOT diameter was measured for each patient at baseline and same value was used at follow up to avoid any confounding factors. GLS was measured at all visits. Results At one-week post pacing, both groups showed a significant decrease in SV due to a drop in EDV while ESV did not change significantly. There was a significant increase in cardiac output (COP) more in dual-chamber pacing group than in the group with single-chamber pacing. However, there were no significant differences between both groups regarding stroke volume (SV), end-systolic volume (ESV), end-diastolic volume (EDV) or ejection fraction (EF) during all time intervals (pre-pacing, at one-week and 6-months post pacing). GLS showed equal decrease in both groups. At 6 months, SV continued to decrease, and COP showed significant decrease. This drop in SV and COP was due to a significant increase in ESV while EDV did not show significant change at 6-month follow up. There was no significant difference between full volume 3D and Doppler methods regarding SV and COP values at all time intervals in both groups. GLS showed additional equal decrease in both groups. Conclusion Dual chamber pacing provided higher COP than single chamber pacing. This is due to pacing at higher heart rates, not due to increase in SV by maintaining atrioventricular synchrony. It was shown in both experimental and clinical studies that RV pacing leads to ventricular dyssynchrony, similar to that of left bundle branch block with subsequent electrical, mechanical and anatomical changes leading to detrimental effects on left ventricular structure and function. Both groups showed significant drop in GLS plus SV, COP and EF at 6-months due to significant increase in ESV. 2D echocardiography and Doppler method were not inferior to 3D echocardiography regarding calculation of SV and COP. Haemodynamics of single &amp; dual pacing Funding Acknowledgement Type of funding source: None

Current state of noninvasive, continuous monitoring modalities in pediatric anesthesiology.

Purpose of reviewThe last decades, anesthesia has become safer, partly due to developments in monitoring. Advanced monitoring of children under anesthesia is challenging, due to lack of evidence, validity and size constraints. Most measured parameters are proxies for end organ function, in which an anesthesiologist is actually interested. Ideally, monitoring should be continuous, noninvasive and accurate. This present review summarizes the current literature on noninvasive monitoring in noncardiac pediatric anesthesia.Recent findingsFor cardiac output (CO) monitoring, bolus thermodilution is still considered the gold standard. New noninvasive techniques based on bioimpedance and pulse contour analysis are promising, but require more refining in accuracy of CO values in children. Near-infrared spectroscopy is most commonly used in cardiac surgery despite there being no consensus on safety margins. Its place in noncardiac anesthesia has yet to be determined. Transcutaneous measurements of blood gases are used mainly in the neonatal intensive care unit, and is finding its way to the pediatric operation theatre. Especially CO2 measurements are accurate and useful.SummaryNew techniques are available to assess a child's hemodynamic and respiratory status while under anesthesia. These new monitors can be used as complementary tools together with standard monitoring in children, to further improve perioperative safety.

The impact of сіоле tree essential oil on the functions of the cardiovascular system of the elderly depending on its initial state

Objective. To study the effect of clove tree essential oil on the cardiovascular function of the elderly with normal blood pressure and with small deviations in the direction of hypertension and hypotension. Materials and methods. The study included 293 elderly women divided into 3 control (sessions of relaxation psychotherapy) and 3 experimental (sessions of relaxation psychotherapy combined with sessions of aromatherapy with clove tree essential oil) groups by blood pressure (normal, small deviations towards hypertension and hypotension), each of which was divided into three subgroups by exposure time (10, 20 and 30 minutes). Before and after the sessions, systolic, diastolic blood pressure and heart rate of the testees were measured, and then the following indicators were calculated: pulse pressure, stroke volume, minute cardiac output, average dynamic arterial pressure, total peripheral vascular resistance, heart mdex&lt;, Robinson rndex^ Kerdo index&lt;, coefficient of efficiency of blood circulation. Results. It was found that the effect of clove tree essential oil depends on the initial level of blood pressure. The testees with a slightly increased blood pressure (up to140 mm Hg) after aroma sessions of aU durations the blood pressure became normal. Accordingly, the values of the minute cardiac output, heart mdex&lt;, coefficient of efficiency of blood circulation, Robinson index were normalized. The testees with normal blood pressure, the sessions of aroma psycho-relaxation practically did not cause changes in parameters characterizing the functions of the cardiovascular system The testees with moderate hypotension (on the average110 mm Hg) during the aroma sessions had the shifts to the normal of the parameters characterizing the functions of the cardiovascular system Thus, clove tree essential oil has a normalizing effect on the function of the cardiovascular system of elderly women at all its initial values.

Evaluation of the relationship between pseudo-hypertension and the parameters of subclinical atherosclerosis.

Methods using for determining the subclinical atherosclerosis have gained growing interest in the recent years. However, the effects of pseudo-hypertension on the parameters of subclinical atherosclerosis are uncertain. We aimed to evaluate the relationship between pseudo-hypertension and subclinical atherosclerosis in individuals diagnosed with pseudo-hypertension. A total of 122 patients who underwent radial elective coronary angiography were included in the present study. These patients were divided into two groups based on the difference between invasive and noninvasive blood pressure (BP) measurements: pseudo-hypertension group who had a difference ≥15 mmHg in SBP or ≥10 mmHg in DBP levels between invasive and noninvasive measurements (n = 28), and the other group who did not have any difference as described on these levels (n = 94). In order to evaluate the subclinical atherosclerosis; flow-mediated dilatation (FMD), carotid intima-media thickness (IMT), pulse wave velocity (PWV), and augmentation index were recorded in all patients. Two groups were compared with respect to these parameters. The median age of the pseudo-hypertension group was 76 years, while the median age of the other group was 63.5 years (P < 0.0001). The incidence of concomitant hypertension was higher in the pseudo-hypertension group as compared to the other group (P < 0.001). There was a significant difference in augmentation index, cardiac output, PWV, FMD, and IMT values between two groups (P = 0.016, P = 0.023, P <0.001, P < 0.001, P < 0.001, respectively). The present results demonstrated that there was a strong correlation between pseudo-hypertension and the parameters of subclinical atherosclerosis; augmentation index, PWV, FMD, and carotids IMT.

Measurements of Cardiac Output and Management of Blood Transfusions During Burn Surgery-An Observational Prospective Study.

Burn surgery can cause extensive bleeding, which lead to perioperative blood transfusions. The purpose of this study was to investigate whether blood transfusions during burn surgery, guided by standard monitoring with inspection of the operative field, measurements of blood pressure, heart rate, hourly diuresis, and concentrations of hemoglobin and lactate could sustain the preoperative cardiac output (CO) till end of surgery. We investigated 15 patients ≥18 years of age scheduled for burn surgery, where the perioperative monitoring included an arterial line. After induction of anesthesia and before start of surgery, we measured baseline values of CO with the minimally invasive LiDCOrapid, mean arterial pressure, and concentrations of hemoglobin and lactate in arterial blood. We measured these values every 30 minutes through surgery. The primary outcome was change in CO from baseline till end of surgery. Secondary outcomes included the change in concentrations of hemoglobin and lactate from baseline till end of surgery. We found no statistically significant change in CO from baseline till end of surgery (6.6 [±2.4] liters/min; 7.2 [±3.2] liters/min; P = .26). We found a statistically significant decrease in concentration of hemoglobin (7.2 [±0.8] mmol/liter; 6.2 [±0.9] mmol/liter; P = .0002), and a statistically significant increase in concentration of lactate (1.3 [±0.5] mmol/liter; 1.7 [±1] mmol/liter; P = .02). The perioperative blood transfusion guided by standard monitoring seemed to sustain CO from baseline till end of surgery; however, further research is needed to confirm this.

Comparison of cardiac output estimates by echocardiography and bioreactance at rest and peak dobutamine stress test in heart failure patients with preserved ejection fraction.

To assess the agreement between cardiac output estimated by two-dimensional echocardiography and bioreactance methods at rest and during dobutamine stress test in heart failure patients with preserved left ventricular ejection fraction (HFpEF). Hemodynamic measurements were assessed in 20 stable HFpEF patients (12 females; aged 61±7years) using echocardiography and bioreactance methods during rest and dobutamine stress test at increment dosages of 5, 10, 15, and 20μg/kg/min until maximal dose was achieved or symptoms and sign occurred, that is, chest pain, abnormal blood pressure elevation, breathlessness, ischemic changes, or arrhythmia. Resting cardiac output and cardiac index estimated by bioreactance and echocardiography were not significantly different. At peak dobutamine stress test, cardiac output and cardiac index estimated by echocardiography and bioreactance were significantly different (7.06±1.43 vs 5.71±1.59L/min, P<.01; and 4.27±0.67 vs 3.43±0.87L/m2 /min; P<.01) due to the significant differences in stroke volume. There was a strong positive relationship between cardiac outputs obtained by the two methods at peak dobutamine stress (r=.79, P<.01). The mean difference (lower and upper limits of agreement) between bioreactance and echocardiography cardiac outputs at rest and peak dobutamine stress was -0.45 (1.71 to -2.62)L/min and -1.35 (0.60 to -3.31)L/min, respectively. Bioreactance and echocardiography methods provide different cardiac output values at rest and during stress thus cannot be used interchangeably. Ability to continuously monitor key hemodynamic variables such as cardiac output, stroke volume, and heart rate is the major advantage of bioreactance method.

The influence of cardiac output on propofol and fentanyl pharmacokinetics and pharmacodynamics in patients undergoing abdominal aortic surgery

Cardiac output (CO) is expected to affect elimination and distribution of highly extracted and perfusion rate-limited drugs. This work was undertaken to quantify the effect of CO measured by the pulse pressure method on pharmacokinetics and pharmacodynamics of propofol and fentanyl administrated during total intravenous anesthesia (TIVA). The data were obtained from 22 ASA III patients undergoing abdominal aortic surgery. Propofol was administered via target-controlled infusion system (Diprifusor) and fentanyl was administered at a dose of 2–3 µg/kg each time analgesia appeared to be inadequate. Hemodynamic measurements as well as bispectral index were monitored and recorded throughout the surgery. Data analysis was performed by using a non-linear mixed-effect population modeling (NONMEM 7.4 software). Three compartment models that incorporated blood flows as parameters were used to describe propofol and fentanyl pharmacokinetics. The delay of the anesthetic effect, with respect to plasma concentrations, was described using a biophase (effect) compartment. The bispectral index was linked to the propofol and fentanyl effect site concentrations through a synergistic Emax model. An empirical linear model was used to describe CO changes observed during the surgery. Cardiac output was identified as an important predictor of propofol and fentanyl pharmacokinetics. Consequently, it affected the depth of anesthesia and the recovery time after propofol-fentanyl TIVA infusion cessation. The model predicted (not observed) CO values correlated best with measured responses. Patients‘ age was identified as a covariate affecting the rate of CO changes during the anesthesia leading to age-related difference in individual patient’s responses to both drugs.

Mitigating Ischemia-Reperfusion Injury Using a Bilobed Partial REBOA Catheter: Controlled Lower-Body Hypotension.

Non-compressible torso hemorrhage (NCTH) is the leading cause of potentially preventable death on the battlefield. Resuscitative endovascular balloon occlusion of the aorta (REBOA) aims to restore central blood pressure and control NCTH below the balloon, but risks ischemia-reperfusion injury to distal organs when prolonged. We tested a bilobed partial REBOA catheter (pREBOA), which permits some of the blood to flow past the balloon. Female swine (n = 37, 6 groups, n = 5-8/group), anesthetized and instrumented, were exponentially hemorrhaged 50% of estimated blood volume (all except time controls [TC]). Negative controls (NC) did not receive REBOA or resuscitation. Positive controls (PC) received retransfusion after 120 min. REBOA groups received REBOA for 120 min, then retransfusion. Balloon was fully inflated in the full REBOA group (FR), and was partially inflated in partial REBOA groups (P45 and P60) to achieve a distal systolic blood pressure of 45 mm Hg or 60 mm Hg. Aortic occlusion restored baseline values of proximal mean arterial pressure, cardiac output, and carotid flow in pREBOA groups. Lactate reached high values during occlusion in all REBOA groups (9.9 ± 4.2, 8.0 ± 4.1, and 10.7 ± 2.9 for P45, P60, and FR), but normalized by 6 to 12 h post-deflation in the partial groups. All TC and P60 animals survived 24 h. The NC, PC, and P45 groups survived 18.2 ± 9.5, 19.3 ± 10.6, and 21.0 ± 8.4 h. For FR animals mean survival was 6.2 ± 5.8 h, significantly worse than all other animals (P < 0.01, logrank test). In this porcine model of hemorrhagic shock, animals undergoing partial REBOA for 120 min survived longer than those undergoing full occlusion.