Cardiac Output Values Research Articles

Two- or 3-Dimensional Echocardiography–Derived Cardiac Output Cannot Replace the Pulmonary Artery Catheter in Cardiac Surgery

Three-dimensional (3D) transesophageal echocardiography (TEE) has been shown to be more accurate than 2D TEE for the evaluation of the left ventricular outflow tract area. The aim of the present study was to compare the agreement of 3D echocardiography-derived cardiac output (CO) with thermodilution-derived CO (TDCO) before and after cardiopulmonary bypass (CPB). This was a prospective observational study of patients who underwent cardiac surgery between 2016 and 2018. Weill Cornell Medicine, a single large academic medical center. The study comprised 78 patients undergoing elective cardiac surgery. CPB, TEE, pulmonary artery catheter, and elective cardiac surgery. Two-dimensional CO, 3D CO-diameter, and 3D CO-area values pre-CPB were strongly correlated with one another both pre-CPB and post-CPB. The 3D CO-diameter and the 3D CO-area were mildly correlated, with TDCO measurements pre-CPB (r = 0.46 and 0.39, respectively) and post-CBP (r = 0.43 and 0.47, respectively). Pre-CPB 3D CO-diameter had the most agreement with TDCO in terms of bias (-0.13 L/min); however, the limits of agreement (LOA) were wide (-2.2- to- 2.45 L/min). Post-CPB, 3D CO-diameter had the most agreement with TDCO in terms of bias (0.41) but with wide LOA (-3.29 to 2.47). All pre-CPB echocardiography-derived CO (2D CO, 3D CO-diameter, 3D CO-area) had more agreement with TDCO than did post-CPB measurements. Three-dimensional CO measurements were only modestly correlated with pulmonary artery catheter-derived CO pre-bypass and post-bypass. Despite low bias, the wide LOA from 2D CO, 3D CO-diameter, and 3D-area compared with TDCO suggested that the 2 methods are not interchangeable.

Dynamics of the clinical functional and hemodynamic profile of patients with pulmonary arterial hypertension with initial monotherapy with endothelin receptor antagonists: bosentan vs. macitentan

Aim To compare results of 24-h treatments with bosentan and macitentan by the clinical functional status and indexes of pulmonary hemodynamics in patients with pulmonary arterial hypertension (PAH).Materials and methods Based on the Russian National Registry (NCT03707561), 44 patients older than 18 years with PAH (34 patients with idiopathic pulmonary hypertension (IPH) and 10 patients with Eisenmenger syndrome) were retrospectively included into this study. Based on the statistical method of pairwise comparison, two groups were formed and matched by age, gender, WHO functional class (FC), and 6-min walk distance (6MWD). 22 patients of group 1 (17 with IPH and 5 with Eisenmenger syndrome) were treated with macitentan 10 mg/day, and 22 patients of group 2 (17 with IPH and 5 with Eisenmenger syndrome) were treated with bosentan 250 mg/day. Clinical instrumental data (6MWD, Borg dyspnea score, chest X-ray, transthoracic echocardiography (EchoCG), and right heart catheterization (RHC)) were evaluated at baseline and after 24 weeks of therapy.Results By week 24 of the treatment, FC and 6MWD improved in both groups. The macitentan treatment was associated with a significant decrease in Borg score. Significant intergroup differences in EchoCG data were not observed. The bosentan treatment was associated with a decrease in right ventricular (RV) dimension and a tendency towards a decrease in calculated pulmonary artery systolic pressure (PASP). By week 24, the macitentan treatment as compared to the bosentan treatment, was associated with a decrease in cardiothoracic ratio (CTR). In both groups, RHC showed decreases in PASP, mean pulmonary artery pressure and pulmonary vascular resistance, and improvements in cardiac output (CO), cardiac index, and stroke volume (SV) values. By week 24, the increase in SV was greater in the macitentan treatment group than in the bosentan treatment group (р=0.05).Conclusion The 24-week treatment with bosentan or macitentan provided significant and comparable improvement of the functional profile in PAH patients with FC II (WHO) at baseline. The decrease in CTR was significantly more pronounced in the macitental treatment group compared to the bosentan treatment group. The 24-week bosentan treatment resulted in a decrease in RV anterior-posterior dimension, a tendency towards a decrease in PASP according to EchoCG data. Macitentan provided more pronounced dynamics of dyspnea than bosentan according to the results of 6MWD test and the increase in SV according to RHC data.

Assessment of Hemodynamic Parameters in Recipients of a Liver Transplant

IntroductionThe control of all hemodynamic parameters among patients after liver transplantation is critical for better graft survival and to reduce the risk of perioperative complications. The value of cardiac output (CO) and stroke volume (SV) below normal promote the development of cardiovascular diseases. Materials and MethodsThe study was conducted on a group of 43 patients after liver transplantation: 16 women and 27 men 0.5 to 29 years after the surgery at the Department of Transplantation Medicine, Nephrology and Internal Diseases, Institute of Transplantology, Medical University of Warsaw, Infant Jesus Clinical Hospital in Warsaw, Poland. The hemodynamic parameters were measured due to 4 electrocardiogram electrodes with the Cardiac Monitor ICON Osypka Medical. ResultsPatients after liver transplantation (LTx) showed values of CO (average 5.27 L/min, standard deviation [SD] = 0.92) and stroke volume (average 67.08 mL, SD = 10.96) below normal. The average thoracic fluid content value among women is 21.81 (1/kΩ), SD = 3.28, and for men 24.04 (1/kΩ), SD = 4.75. Only 37% of patients had a body mass index with normal values, with 63% above expected values: 42% with overwise and 21% with a first stage of obesity. ConclusionThe hemodynamic parameters should be controlled among patients after LTx. CO and SV below normal are predictors of a higher risk of cardiovascular diseases.

Cardiac output estimation by pulse wave analysis using the pressure recording analytical method and intermittent pulmonary artery thermodilution: A method comparison study after off-pump coronary artery bypass surgery.

Invasive pulse wave analysis is used in peri-operative settings to estimate cardiac output (CO). The 'pressure recording analytical method' (PRAM) implemented in the MostCareUp CO monitor is an invasive pulse wave analysis method using high-frequency sampling and analysis of the pulse wave to directly estimate the arterial impedance as a key variable of the proprietary CO estimation algorithm. To compare CO estimated by PRAM (PRAM-CO; test method) with CO measured by pulmonary artery thermodilution (PATD-CO; reference method). Prospective observational method comparison study. PRAM-CO and PATD-CO were assessed simultaneously at five time points with at least 20 min between measurements. Arterial pressure waveforms were carefully checked for damping artefacts and a proprietary electronic filter of the MostCareUp CO monitor was used to optimise waveform quality. ICU of a German university hospital from August 2018 until April 2019. We included adult patients admitted to the ICU after elective off-pump coronary artery bypass surgery who were monitored with a radial arterial catheter and a pulmonary artery catheter. Patients with severe heart valve insufficiency or persistent arrhythmia were excluded. PATD-CO and PRAM-CO were compared using Bland-Altman analysis accounting for repeated measurements, the percentage error and trending analysis (four-quadrant plot, concordance rate). We analysed 195 paired CO values of 41 patients. Mean PATD-CO and PRAM-CO were 4.99 ± 1.02 and 4.92 ± 1.05 l min, respectively. PATD-CO and PRAM-CO ranged from 3.04 to 8.74 and 2.79 to 8.01 l min, respectively. The mean of the differences between PATD-CO and PRAM-CO was -0.08 ± 0.74 l min with 95% limits of agreement of -1.55 to +1.40 l min. The percentage error was 29.8%. The concordance rate in four-quadrant plot analysis was 92%. Using the system's electronic waveform filter PRAM-CO shows good agreement and trending ability compared with PATD-CO in adults after off-pump coronary artery bypass surgery.

Comparison of cardiac output and cardiac index values measured by critical care echocardiography with the values measured by pulse index continuous cardiac output (PiCCO) in the pediatric intensive care unit:a preliminary study

BackgroundPlanning optimal fluid and inotrope-vasopressor-inodilator therapy is essential in critically ill children. Pulse index Contour Cardiac Output (PiCCO) monitoring is an invasive, hemodynamic monitor that provides parameter measurements such as cardiac output (CO), cardiac index (CI). Use of ultrasonography and critical care echocardiography by the pediatric intensivists has increased in recent years. In the hands of an experienced pediatric intensivist, critical echocardiography can accurately measure both CO and CI. Our objective in this study is to compare the CO and CI values measured by pediatric intensivist using critical care echocardiography to the values measured by PiCCO monitor in critically ill pediatric patients.MethodsA prospective observational study from a tertiary university hospital PICU. A total of 15 patients who required advanced hemodynamic monitoring and applied PiCCO monitoring were included the study. The diagnosis of patients were septic shock, cardiogenic shock, acute respiratory distress syndrome, pulmonary edema. Forty nine echocardiographic measurements were performed and from 15 patients. All echocardiographic measurements were performed by a pediatric intensive care fellow experienced in cardiac ultrasound. The distance of left ventricle outflow tract (LVOT) in the parasternal long axis and LVOT-Velocity Time Integral (LVOT-VTI) measurement was performed in the apical five chamber image. Cardiac output_echocardiography (CO_echo) and CI_echocardiography (CI_echo) were calculated using these two measurements. PiCCO (PiCCO, Pulsion Medical Systems, Munich, Germany) monitoring was performed. Cardiac output (CO_picco) and CI (CI_picco) were simultaneously measured by PiCCO monitor and echocardiography. We performed a correlation analysis with this 49 echocardiographic measurements and PiCCO measurements.ResultsWe detected a strong positive correlation between CO_echo and CO_picco measurements (p < 0.001, r = 0.985) and a strong positive correlation between CI_echo and CI_picco measurements (p < 0.001, r = 0.943).ConclusionsOur study results suggest that critical care echocardiography measurement of CO and CI performed by an experienced pediatric intensivist are comparable to PiCCO measurements. The critical care echocardiography measurement can be used to guide fluid and vasoactive-inotropic management of critically ill pediatric patients.

Continuous Noninvasive Hemoglobin Monitoring Reflects the Development of Acute Hemodilution After Consecutive Fluid Challenges

Consecutive fluid challenges (FCs) are frequently administered to maximize the stroke volume (SV) as part of a goal-directed therapy (GDT) strategy. However, fluid administration may also cause acute hemodilution that might lead to an actual paradoxical decrease in oxygen delivery (DO2). The aim of this study was to examine whether continuous noninvasive hemoglobin (SpHb) monitoring can be used to detect the development of acute hemodilution after graded fluid administration. In 40 patients who underwent major vascular or gastrointestinal surgery, an FC, consisting of 250 mL colloid solution, was administered. When the SV increased by ≥10%, the FC was repeated up to a maximum of 3 times. Laboratory-measured hemoglobin concentrations (BHb), SpHb, SV, cardiac output (CO), and DO2 values were recorded after each FC. All 40 patients received the first FC, 32 patients received the second FC, and 20 patients received the third FC (total of 750 mL). Out of the 92 administered FCs, only 55 (60%) caused an increase in SV ≥10% ("responders"). The first and the second FCs were associated with a significant increase in the mean CO and DO2, while the mean SpHb and BHb decreased significantly. However, the third and last FC was associated with no statistical difference in CO and SV, a further significant decrease in mean SpHb and BHb, and a significant decrease in DO2 in these patients. Compared to their baseline values (T0), BHb and SpHb decreased by a mean of 5.3% ± 4.9% and 4.4% ± 5.2%, respectively, after the first FC (T1; n = 40), by 9.7% ± 8.4% and 7.9% ± 6.9% after the second FC (T2; n = 32), and by 14.5% ± 6.2% and 14.6% ± 5.7% after the third FC (T3; n = 20). Concordance rates between the changes in SpHb and in BHb after the administration of 250, 500, and 750 mL colloids were 83%, 90%, and 100%, respectively. Fluid loading aimed at increasing the SV and the DO2 as part of GDT strategy is associated with acute significant decreases in both BHb and SpHb concentrations. When the administration of an FC is not followed by a significant increase (≥10%) in the SV, the DO2 decreases significantly due to the development of acute hemodilution. Continuous noninvasive monitoring of SpHb does not reflect accurately absolute BHb values, but may be reliably used to detect the development of acute hemodilution especially after the administration of at least 500 mL of colloids.

The Protective Effect of rhBNP on Postresuscitation Myocardial Dysfunction in a Rat Cardiac Arrest Model.

Purpose We investigated the protective effects and the underlying mechanisms through which recombinant human brain natriuretic peptide (rhBNP) acts on postresuscitation myocardial dysfunction (PRMD) in the cardiac arrest (CA) model. Methods Ventricular fibrillation was induced and untreated for 6 min. And the time of cardiopulmonary resuscitation was 8 min, after which defibrillation was attempted in this rat model. 24 Sprague Dawley rats (450–550g) were randomized into cardiopulmonary resuscitation (CPR) + rhBNP and CPR + placebo groups after restoration of spontaneous circulation (ROSC). rhBNP was infused at PR 30 min (loading dose: 1.5 µg/kg, 3 min; maintenance dose: 0.01 µg/kg, 3 min; maintenance dose: 0.01 α (TNF-α (TNF-α (TNF-κB (NF-κB (NF-Results The administration of rhBNP attenuated the severity of PRMD and myocardial tissue injuries, with improvement of MAP (mean arterial blood pressure), ETCO2 (end-tidal CO2), serum level of NT-proBNP, EF, CO, and MPI values. The serum levels and protein expression levels in myocardial tissue of IL-6 and TNF-α (TNF-κB (NF-Conclusion Our research demonstrated that the administration of rhBNP attenuated the severity of PRMD and myocardial tissue injuries and increased the 24 h survival rate in this CA model. rhBNP administration also reduced the serum and myocardial tissue levels of IL-6 and TNF-α after ROSC, likely due to the suppression of the TLR4/NF-κB signaling pathway and the regulation of inflammatory mediator secretion.α (TNF-κB (NF-

Non-invasive evaluation of macro- and microhemodynamic changes during induction of general anesthesia - A prospective observational single-blinded trial.

Hypotension and bradycardia are known side effects of general anesthesia, while little is known about further macro- and microhemodynamic changes during induction. Intriguing is furthermore, why some patients require no vasopressor medication to uphold mean arterial pressure, while others need vasopressor support. Determination of macro- and microhemodynamic changes during induction of general anesthesia. We enrolled 150 female adults scheduled for gynaecological surgery into this prospective observational, single-blinded trial. Besides routinely measuring heart rate (HR) and mean arterial blood pressure (MAP), the non-invasive technique of thoracic electrical bioimpedance was applied to measure cardiac output (CO), cardiac index (CI), stroke volume (SV), stroke volume variability (SVV) and index of myocardial contractility (ICON) before induction of anesthesia, 7 times during induction, and, finally, after surgery in the recovery room. Changes in microcirculation were assessed using sidestream dark field imaging to establish the perfused boundary region (PBR), a validated gauge of glycocalyx health. Comparisons were made with Friedman's or Wilcoxon test for paired data, and with Mann-Whitney-U test for unpaired data, with post-hoc corrections for multiple measurements by the Holm-Bonferroni method. 83 patients did not need vasopressor support, whereas 67 patients required therapy (norepinephrine, atropine or cafedrine/theodrenaline) to elevate MAP values to ≥70mmHg during induction, 54 of these receiving norepinephrine (NE) alone. Pre-interventional (basal) values of CO, CI, ICON, SV and SVV were all significantly lower in the group of patients later requiring NE (p < 0.04), whereas HR and MAP were identical for both groups. HR, MAP and CO decreased from baseline to 12 min after induction of general anesthesia in both the patients without and those with NE support. Heart rate decreased significantly by about 25% in both groups (-19 to -21 bpm). The median individual decrease of MAP amounted to -26.7% (19.7/33.3, p < 0.001) and -26.1% (11.6/33.2, p < 0.001), respectively, whereas for CO it was -40.7% (34.1/50.1, p < 0.001) and -43.5% (34.8/48.7). While these relative changes did not differ between the two groups, in absolute values there were significantly greater decreases in CO, CI, SV and ICON in the group requiring NE. Noteably, NE did not restore ICON or the other cardiac parameters to levels approaching those of the group without NE. PBR was measured in a total of 84 patients compiled from both groups, there being no intergroup differences. It increased 6.4% (p < 0.001) from pre-induction to the end of the operation, indicative of damage to microvascular glycocalyx. Non-invasive determination of CO provides additional hemodynamic information during anesthesia, showing that induction results in a significant decrease not only of MAP but also of CO and other cardiac factors at all timepoints compared to baseline values. The decrease of CO was greater than that of MAP and, in contrast to MAP, did not respond to NE. There was also no sign of a positive inotropic effect of NE in this situation. Support of MAP by NE must consequently result from an increase in peripheral arterial resistance, posing a risk for oxygen supply to tissue. In addition, general anesthesia and the operative stimulus lead to an impairment of the microcirculation.

Cardiac Output Values and Correlation of Renal Injury with Neutrophil Gelatinase-Associated Lipocalin Levels in Off-Pump Coronary Artery Bypass Patients.

ObjectiveTo investigate the correlation between cardiac output values and renal neutrophil gelatinase-associated lipocalin (NGAL) levels as a biomarker of renal ischemia.MethodsForty patients, who underwent off-pump coronary artery bypass (OPCAB) surgery and in whom the positioning of the heart was fixed with simple suspension sutures without a mechanical stabilizer, were included in the study. Continuous cardiac output (CO) measurements were recorded using the arterial pressure waveform analysis method (FloTrac sensor system) in the perioperative period. CO was recorded every minute during non-anatomical cardiac positioning for left anterior descending artery (LAD), diagonal artery (D), circumflex artery (Cx), and right coronary artery (RCA) bypasses. Serum NGAL samples were analyzed in the preoperative, perioperative, and postoperative periods.ResultsThe CO values measured at various non-anatomical cardiac positions during distal anastomosis for LAD, D, Cx, and RCA were significantly lower than pre- and postoperative values measured with the heart in normal anatomical position (3.45±0.78, 2.9±0.71, 3.11±0.56, 3.19±0.81, 5.03±1.4, and 4.85±0.78, respectively, P=0.008). There was no significant difference between CO values measured at various non-anatomical cardiac positions during distal anastomosis. Although there was no significant correlation between NGAL levels and age, duration of surgery, preoperative CO, D-CO, RCA-CO, and postoperative CO measurements, there was a significant correlation between NGAL levels and LAD-CO (P=0.044) and Cx-CO (P=0.018) at the postoperative 12th hour.ConclusionFull revascularization may be achieved by employing the OPCAB technique while using simple suspension sutures without a mechanical stabilizer and by providing safe CO levels and low risk of renal ischemia.

Comparison of cardiac output, IVC diameters and lactate levels in prediction of mortality in patients in emergency department; An observational study.

Objective:Fluid overload is an independent marker for mortality in critically ill patients. Assessment of fluid status and fluid responsiveness is crucial for the management of these patients. In this study, we compared the lactate level, inferior vena cava (IVC) diameter and non-invasive cardiac output (CO) monitoring in prediction of mortality in emergency department.Methods:This was a cross sectional observational study which comprised of 68 patients and was performed in ED of Tabriz University of Medical Sciences, Iran, from Sept 2016 until Sept 2017. IVC diameter was measured before the P-wave on ECG to avoid interference with a-wave and v-wave on the venous pressure curve, and during maximal inspiration and expiration to avoid Valsalva-like maneuvers. An arterial lactate sample was taken from all patients before performing the initial resuscitation. All patients underwent non-invasive CO monitoring by CO2 rebreathing technique. Mortality was noted on day 28.Results:Deceased patients had a significantly low level of IVC diameters, less CO values and more lactate levels. However, based on ROC curve analysis, the prediction accuracy and validity of both CO values obtained by rebreathing CO2 and IVC diameter was poor and the highest accuracy was obtained by lactate level assessment.Conclusion:Initial lactate value is a reliable parameter for prediction of mortality in non-traumatic critically ill patients. IVC diameter changes during spontaneous ventilation and non-invasive CO monitoring does not possess acceptable accuracy for prediction of mortality in these patients.

Different Intensity Exercise Preconditions Affect Cardiac Function of Exhausted Rats through Regulating TXNIP/TRX/NF-ĸBp65/NLRP3 Inflammatory Pathways.

Objective To investigate whether exercise preconditioning (EP) improves the rat cardiac dysfunction induced by exhaustive exercise (EE) through regulating NOD-like receptor protein 3 (NLRP3) inflammatory pathways and to confirm which intensity of EP is better. Method Ninety healthy male Sprague Dawley rats were randomly divided into five groups: a control group (CON), exhaustive exercise group (EE), low-, middle-, and high-intensity exercise precondition and exhaustive exercise group (LEP + EE, MEP + EE, HEP + EE group). We established the experimental model by referring to Bedford's motion load standard to complete the experiment. Then, the pathological changes of the myocardium were observed under a light microscope. Biomarker of myocardial injury in serum and oxidative stress factor in myocardial tissue were evaluated by ELISAs. The cardiac function parameters were detected using a Millar pressure and volume catheter. The levels of thioredoxin-interacting protein (TXNIP), thioredoxin protein (TRX), nuclear transcription factor kappa Bp65 (NF-ĸBp65), NLRP3, and cysteinaspartate specific proteinase 1 (Caspase-1) protein in rats' myocardium were detected by western blotting. Results 1. The myocardial structures of three EP + EE groups were all improved compared with EE groups. 2. The levels of the creatine phosphating-enzyme MB (CK-MB), reactive oxygen species (ROS), interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor alpha (TNF-α) in three EP + EE groups were all increased compared with CON but decreased compared with the EE group (P < 0.05). 3. Compared with the CON group, slope of end-systolic pressure volume relationship (ESPVR), ejection fraction (EF), and peak rate of the increase in pressure (dP/dtmax) all dropped to the lowest level in the EE group (P < 0.05), while the values of cardiac output (CO), stroke volume (SV), end-systolic volume (Ves), end-diastolic volume (Ved), and relaxation time constant (Tau) increased in the EE group (P < 0.05). 4. Compared with the CON group, the expression levels of TXNIP, NF-ĸBp65, NLRP3, and Caspase-1 all increased obviously in the other groups (P < 0.05); meanwhile, they were all decreased in three EP + EE groups compared with the EE group (P < 0.05). 5. NLRP3 was positively correlated with heart rate, IL-6, and ROS, but negatively correlated with EF (P < 0.01). Conclusion EP protects the heart from EE-induced injury through downregulating TXNIP/TRX/NF-ĸBp65/NLRP3 inflammatory signaling pathways. Moderate intensity EP has the best protective effect.

Comparison of cardiac output measured by carotid artery Doppler ultrasound and echocardiography in patients admitted to Golestan and Imam Khomeyni Hospitalsl in Ahvaz.

Introduction:Ultrasound is highly effective, safe, and cost-effective for monitoring the hemodynamics and measuring the cardiac output of patients. This study aims to investigate the value of cardiac output by the measurement of common carotid artery flow, which is an inexpensive, simple, and accessible method.Method:Doppler ultrasound of the carotid artery at thyroid level was obtained from the patients admitted to Golestan and Imam Khomeyni Hospitals in Ahvaz (the result is recorded medially from the bilateral outputs unless otherwise prescribed on one side due to a problem such as a catheter or specific position). A transthoracic echocardiography was also recorded using a portable device to measure the left ventricular outlet of diameter 0.5 cm below the aortic valve in the left parasternal with a long axis view.Results:Of the 94 patients studied between the ages of 25 to 87 years, 53 (56.4%) were males and 41 (43.6%) females with a mean age of 53.61 with a standard deviation of 14.56. There was a direct and significant relationship between age and cardiac output using both echocardiography and color Doppler carotid ultrasound (P < 0.001).Discussion:The results of this study showed that the measurement of cardiac output using color Doppler ultrasound in the case of inaccessible emergency echocardiography is a cheap, simple, and accessible method for the hemodynamic evaluation of patients.

Features of changes in volume-impedance hemodynamic indicators during the tilt test in young males with a history of vasovagal syncopes

The direction of changes in hemodynamic parameters during the tilt test (TT) nin individuals with history of vasovagal syncope (VVS) is a subject of discussion. to study changes of volume-impedance hemodynamic indicators in the process of tilt test in somatically healthy young men with history of VVS. A total of 102 men aged 18-30 years were divided into 4 groups, taking into account the specific features of fainting history and response to TT. Persons of group 1 (n=14) had history of VVS and positive response to TT (syncope). Subjects of group 2 (n=14) had history of VVS and a pattern of postural tachycardia without fainting during TT. Persons of group 3 (n=42) had history of VVS and negative response to TT. Subjects of group 4 (n=32) had no history of VVS and negative response to TT. During TT, we studied dynamics of some indicators, including cardiac output (CO) and total peripheral vascular resistance (TPVR). In individuals of all groups in the initial horizontal phase of TT values of CO and TPVR corresponded to the norm. Subjects of group 1 had significantly lower CO compared with subjects of groups 2, 3, 4 (p&lt;0.05, p&lt;0.01, p&lt;0.05, respectively). Values of TPVR in subjects of group 1 were significantly higher than in subjects of groups 2, 3, 4 (p&lt;0.05; p&lt;0.05; p&lt;0.05, respectively). In response to orthostasis CO values increased in groups 1, 2, 4 (by 18%, 10%, 5%, respectively) and did not change in group 3; TPVR values decreased in groups 1, 2 (by 8%, 0.5%, respectively), and increased in groups 3, 4 (by 8%, 4% respectively). In the final horizontal phase of TT, CO values in group 1 were significantly lower than in groups 3, 4 (p&lt;0.05), while TPVR values did not significantly differ between all groups (p&gt;0.05). In tilt-positive and tilt-negative subjects with history of VVS, standardized postural stress leads to unidirectional changes in cardiac output, but to multidirectional changes in total peripheral vascular resistance.

Clinical research of target guided treatment of patients with severe heart failure under the guidance of pulse indicator continuous cardiac output

To investigate the value of pulse indicator continuous cardiac output (PiCCO) monitoring in the treatment management of patients with severe heart failure. Sixty patients of severe heart failure admitted to intensive care unit (ICU) of Fujian Provincial Hospital from August 2017 to February 2019 were enrolled, and they were divided into control group and treatment group according to random number table method, with 30 in each group. The treatment group used bedside PiCCO to carry out minimally invasive hemodynamics monitoring, according to the monitoring data target guidance for vasoactive drugs and liquid management. The control group was based only on traditional electrocardiogram (ECG) monitoring and lung sound, urine volume of vasoactive drugs and liquid management. The changes of cardiac index (CI), global end diastolic volume index (GEDVI), extravascular lung water index (EVLWI), systemic vascular resistance index (SVRI), invasive mean arterial pressure (MAP) and central venous pressure (CVP) were observed before and 72 hours after treatment in the treatment group. The 7-day total effective rate, the length of ICU stay and 28-day mortality were compared between the two groups. Compared with before treatment, CI and MAP in the treatment group were significantly increased after treatment [CI (mL×s-1×m-2): 53.34±16.67 vs. 35.01±13.34, MAP (mmHg, 1 mmHg = 0.133 kPa): 72.6±10.6 vs. 62.5±10.3, both P < 0.05], GEDVI, EVLWI, SVRI, CVP were significantly decreased [GEDVI (mL/m2): 760.3±90.2 vs. 960.2±110.3, EVLWI (mL/kg): 6.5±1.3 vs. 12.5±6.2, SVRI (kPa×s×L-1×m-2): 297.3±35.1 vs. 434.1±58.8, CVP (mmHg): 10.1±2.6 vs. 12.2±3.4, all P < 0.05]. Compared with the control group, the 7-day total effective rate of the treatment group was significantly higher (90.0% vs. 80.0%), the length of ICU stay was significantly shorter (days: 8.2±4.5 vs. 10.3±2.5), and the 28-day mortality was significantly lower, with statistically significant difference (all P < 0.05). PiCCO monitoring is a goal-oriented treatment management for patients with severe heart failure, which is helpful to individualized accurate treatment, shorten the length of ICU stay and improve short-term prognosis.

Cardiac Output Monitoring in Children, Adolescents and Adults Based on Pulse Contour Analysis: Comparison with Echocardiography-Derived Data and Identification of Factors Associated with Their Differences

Through pulse contour analysis (PCA) devices would enable to obtain non-invasive operator-independent cardiac output (CO) measurements [CO(PCA)]. The agreement between CO(PCA) and data from two-dimensional [CO(2D)] or Doppler [CO(VTI)] echocardiography (references) remains controversial. To analyze: (1) CO(PCA), CO(2D) and CO(VTI) agreement, (2) determinants of methods' differences in measured CO values. Simultaneous echocardiography and PCA records (Mobil-O-Graph/Germany) were obtained in 130 subjects (age: 29 ± 17years). Hemodynamic (e.g., heart rate [HR]), arterial (e.g., arterial stiffness, augmentation index [AIx]) and cardiac structural-functional (e.g., left ventricle end-diastolic diameters [LVEDD]) parameters were obtained. Data from the entire group (all; 10-85years), children (≤ 16years), adolescents (17-24years) and adults (> 24years) were separately analyzed. The highest Lin's concordance correlation coefficient (CCC) were obtained when analyzing CO(PCA)/CO(2D) association (0.672, 0.785, 0.721, 0.487 for all, children, adolescents and adults, respectively); CCC levels were higher at younger ages. Bland-Altman's systematic errors between CO(PCA)/CO(2D) were 0.12, 0.17, 0.07 and 0.14L/min, for all, children, adolescents and adults, respectively (non-significant). CO(VTI)/CO(PCA) systematic error only reached significance in adults (0.34L/min, p = 0.002). Bland-Altman's proportional errors were not statistically significant when CO(PCA)/CO(2D) differences were analysed in children and adolescents. Higher AIx and LVEDD levels associated greater CO(2D)/CO(PCA) differences; higher AIx and HR levels were associated to differences between CO(VTI) and CO(PCA). CO(PCA) had systematic (< 0.17L/min) and percent (≤ 30%) errors, which allow us to postulate that its use allows reaching levels comparable to those of echocardiography. Differences in CO-data between methods were associated with arterial and cardiac properties.

Accuracy and precision of cardiac output estimation by an automated, brachial cuff-based oscillometric device in patients with shock.

Non-invasive monitoring of cardiac output is a technological and clinical challenge, especially for critically ill, surgically operated, or intensive care unit patients. A brachial cuff-based, automated, oscillometric device used for blood pressure and arterial stiffness ambulatory monitoring (Mobil-O-Graph) provides a non-invasive estimation of cardiac output values simultaneously with regular blood pressure measurement. The aim of the study was to evaluate the feasibility of this apparatus to estimate cardiac output in intensive care unit patients and to compare the non-invasive estimated cardiac output values with the respective gold standard method of thermodilution during pulmonary artery catheterization. Repeated sequential measurements of cardiac output were performed, in random order, by thermodilution (reference) and Mobil-O-Graph (test), in 24 patients hospitalized at intensive care unit. Reproducibility and accuracy of the test device were evaluated by Bland-Altman analysis, intraclass correlation coefficient, and percentage error. Mobil-O-Graph underestimated significantly the cardiac output by -1.12 ± 1.38 L/min (p < 0.01) compared to thermodilution. However, intraclass correlation coefficient was >0.7 indicating a fair agreement between the test and the reference methods, while percentage error was approximately 39% which is considered to be within the acceptable limits. Cardiac output measurements were reproducible by both Mobil-O-Graph (intraclass correlation coefficient = 0.73 and percentage error = 27.9%) and thermodilution (intraclass correlation coefficient = 0.91 and percentage error = 26.7%). We showed for the first time that cardiac output estimation in intensive care unit patients using a non-invasive, automated, oscillometric, cuff-based apparatus is reproducible (by analyzing two repeated cardiac output measurements), exhibiting similar precision to thermodilution. However, the accuracy of Mobil-O-Graph (error compared to thermodilution) could be considered fairly acceptable. Future studies remain to further examine the reliability of this technology in monitoring cardiac output or stroke volume acute changes which is a more clinically relevant objective.

Comparison of estimation of cardiac output using an uncalibrated pulse contour method and echocardiography during veno-venous extracorporeal membrane oxygenation.

During veno-venous extracorporeal membrane oxygenation, cardiac output monitoring is essential to assess tissue oxygen delivery. Adequate arterial oxygenation depends on the ratio between the extracorporeal pump blood flow and the cardiac output. The aim of this study was to compare estimates of cardiac output and blood flow/cardiac output ratios made using an uncalibrated pulse contour method with those made using echocardiography in patients treated with veno-venous extracorporeal membrane oxygenation. Cardiac output was estimated simultaneously using a pulse contour method (MostCareUp; Vygon, Encouen, France) and echocardiography in 17 hemodynamically stable patients treated with veno-venous extracorporeal membrane oxygenation. Comparisons were made using Bland-Altman and linear regression analysis. There were significant correlations between cardiac output estimated using pulse contour method and echocardiography and between blood flow/cardiac output estimated using pulse contour method and blood flow/cardiac output estimated using echocardiography (r = 0.84, p < 0.001 and r = 0.87, p < 0.001, respectively). Bland-Altman analysis showed a good agreement (bias -0.20 ± 0.50 L/min) and a low percentage of error (25%) for the cardiac output values estimated by the two methods. The bias between the blood flow/cardiac output ratios obtained with the two methods was 5.19% ± 12.3% (percentage of error = 28.1%). The pulse contour method is a valuable alternative to echocardiography for the assessment of cardiac output and the blood flow/cardiac output ratio in patients treated with veno-venous extracorporeal membrane oxygenation.

Design of an In Vitro Mock Circulatory Loop to Reproduce Patient-Specific Vascular Conditions: Toward Precision Medicine

Abstract Patient-specific hemodynamic studies have attracted considerable attention in recent years due to their potential to improve diagnosis and optimize clinical treatment of cardiovascular diseases. Personalized computational models have been extensively investigated as a tool to improve clinical outcomes and are often validated against in vitro experimental data. Replicating patient-specific conditions in vitro is thus becoming increasingly important in cardiovascular research; experimental platforms can not only allow validation of in silico approaches but can also enable physical testing of various intervention scenarios and medical devices. Current experimental approaches suffer from shortcomings regarding personalization and biomimicry. To address some of these limitations, we have designed and developed a novel in vitro platform for the study of complex patient-specific vascular pathologies. This is achieved by using novel tunable three-element Windkessel vasculature simulators and a computer controlled pulsatile pump, coupled with mathematical models and computer routines to calibrate the parameters according to the available clinical datasets. In particular, the vessel inlet flow rate waveform and the afterload resistances and compliances are tuned in order to obtain target systolic and diastolic pressures, and cardiac output (CO) distribution. Pulse frequency (40–70 bpm), CO (2–5 l/min), resistance (0.03–10.6 mmHg s/ml), and compliance (0.07–1 ml/mmHg) values have been tested and the overall reliability of the platform components as well as its computer routines to reproduce controlled physiological conditions demonstrated.

Influence of maternal characteristics and gestational age onhemodynamic indices: NICOM device-specific reference ranges.

To construct reference ranges for stroke volume, cardiac output and systemic vascular resistance (SVR) in normal pregnancy for the NICOM® device, and to explore associations between maternal characteristics and these hemodynamic variables. This was a prospective cohort study of healthy singleton pregnancies between 10 and 40 weeks' gestation attending a tertiary referral hospital between September 2012 and May 2018. Measurements of stroke volume, cardiac output and SVR were obtained throughout pregnancy using NICOM, a non-invasive device based on bioreactance technology. NICOM device-specific reference ranges were created with respect to gestational age and maternal characteristics. Once the distribution of the data had been determined with respect to the gestational age, patient characteristics were added to the model to test whether they provided a significant improvement in prediction of the median value. The effect was assessed of maternal weight, height, smoking status, conception using assisted reproductive technology, nulliparity and ethnicity. We included 411 women in this study. The relationships between cardiac variables and gestational age observed in the NICOM-specific reference ranges are consistent with previous findings, with increasing cardiac output values until around 35 weeks and a decrease thereafter until term, and decreasing SVR until around 36 weeks, followed by an increase towards 40 weeks. Stroke volume showed a small linear increase across gestation with lower variability in observations close to term. Maternal weight, height and age were associated with cardiac output (all P < 0.05) and SVR (all P < 0.01), whilst maternal weight and height were associated with stroke volume (both P < 0.001). Ethnicity was significantly associated with stroke volume (P = 0.001) but not with cardiac output or SVR. This study presents device-specific reference ranges for stroke volume, cardiac output and SVR for the NICOM device in healthy pregnancy and describes the maternal characteristics that are associated with the values of these hemodynamic measurements. Studies using NICOM in pregnancy can use these ranges in order to evaluate observations relative to those expected in uncomplicated pregnancy conditional on maternal characteristics. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

P3524Biomechanic and neuroautonomic adaptation to acute blood volume displacement in patients with ischemic dilated cardiomyopathy

Abstract Background Chronic heart failure (CHF) is associated with neuroautonomic unbalance. Purpose We aimed at verifying the biomechanical and neuroautonomic adaptation to tilt test-induced volume displacement in patients with ischemic CHF. Methods Fifty-four CHF patients with a previous inferoapical/inferolateral (IA-IL) or basal/apical septal (BS-AS) myocardial infarction, free from residual ischemia, were enrolled. They underwent head-up tilt test, radionuclide ventricular function monitoring using the ambulatory ventricular function monitoring device (VEST), sympatho-vagal balance evaluation (low [LF] and high [HF] frequencies) and isoproterenol test (CD25). Results IA-IL patients had lower values of stroke volume, cardiac output and ejection fraction.The end-diastolic volume (EDV) increased in the IA-IL group (F=36.41, P&lt;0.001) during tilt-test, more than BS-AS patients (F=4.12, P&lt;0.05). The end-systolic volume (ESV) similarly increased in both groups. Norepinephrine (IA-IL Supine→ Tilting 499.5±28.8 → 719.3±41.5 pg/ml vs BS-AS Supine → Tilting 533.9±33.3 → 768.8±47.9 pg/ml, P&lt;0.001) and epinephrine plasma concentrations (IA-IL Supine → Tilting 125.7±9.8 → 193.7±9.6 pg/ml vs BS-AS Supine → Tilting 118.8±8.9 → 191.7±10.2 pg/ml, P&lt;0.001) increased in both groups. LF/HF ratio not-significantly increased in IA-IL patients and decreased in BS-AS. CD25 was similar in IA-IL and BS-AS patients (IA-IL patients = 4.6±0.94 μg and BS-AS patients = 5.0±1.06 μg, P=0.79). The severity of ventricular dysfunction rather than its site correlated with the unbalance in biomechanical and neuroautonomic response. Conclusions Ischemic CHF patients showed altered biomechanical adaptation to volume displacement and compensatory sympathetic overdrive. Caution should be used with drugs interfering with the sympathetic response due to increased risk of syncope in response to volume displacement. Acknowledgement/Funding None