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Objective: To investigate the accuracy of electrical cardiometry (EC) to measure stroke volume (SV) and cardiac output (CO) and to provide gestational age (GA) and birth weight (BW)-based reference data for SV and CO in hemodynamically stable preterm neonates. Study Design: Prospective observational blinded study. Paired measurements of SV and CO on stable preterm infants without any hemodynamic compromise were carried out using EC (SV EC ) and echocardiography (SV ECHO ). Results: Seventy-nine preterm neonates (mean GA: 31±3.2 weeks) were enrolled. A good correlation was found for SV ( r =0.743; P <0.0001) and CO ( r =0.7; P <0.0001) measured by EC and echocardiography. These correlations remained significant after adjusting for GA, patent ductus arteriosus and type of respiratory support (SV: St.β=0.48, P <0.0001 and CO: St.β=0.69, P <0.0001). Mean biases (and variabilities) were −1.1 (from 0.7 to −2.9) ml and −0.21 (from 0.15 to −0.55) l min −1 for SV and CO, respectively. Local regression shows a tendency for EC to overestimate SV and CO especially at higher values (at about >2 ml and >0.4 l min −1 , respectively). Coefficient of variation of SV was 48.9% and 52%, for EC and echocardiography. SV and CO rose with increasing GA and BW following an exponential equation ( R 2 >0.8). Conclusion: Measuring SV and CO with EC in hemodynamically stable preterm infants shows good correlation and variability similar to that of echocardiography. A trend to overestimation exists at highest values, but it is unlikely to be clinically significant. Reference GA and BW-based nomograms for SV and CO are provided.

The ‘strength–endurance continuum’ is a key concept in strength training (ST). Although cardiopulmonary responses have seldom been reported in conjunction with ST, this repeated‐measurement study examined acute blood pressure and haemodynamic responses continuously depending on the number of repetitions but without changing the intensity. Fifteen healthy male participants (21.6 (2.0) years; mean (SD)) performed an incremental exercise test and a 3‐repetition maximum test (3‐RM) on a Smith machine. They were then randomly assigned to three ST sessions involving 10, 20 and 30 repetitions at 50% of their 3‐RM. Blood pressure (vascular unloading technique) and cardiopulmonary responses (spirometry and impedance cardiography) were continuously monitored. Heart rate (121 (10) vs. 139 (22) vs. 153 (13) bpm, P = 0.001, respectively), cardiac output (10.4 (1.9) vs. 13.6 (3.8) vs. 14.6 (3.1) L/min, P = 0.001, respectively) and diastolic blood pressure (113 (8) vs. 116 (21) vs. 135 (22) mmHg, P = 0.001, respectively) increased in the training sessions with higher repetitions. Stroke volume, systolic blood pressure and end‐diastolic volume indicated no change in peak values between training sessions. Total peripheral resistance (13.6 (2.8) vs. 11.3 (3.6) vs. 11.2 (3.1) mmHg min/L, P = 0.002, respectively) was significantly lower with 20 and 30 repetitions, while oxygen uptake (V̇O2 ${\\dot V_{{{\\mathrm{O}}_{\\mathrm{2}}}$ : 15.5 (1.9) vs. 20.5 (4.1) vs. 20.6 (4.4) mL/min/kg, P = 0.001, respectively) was significantly higher. ST of moderate intensity with an exhausting number (>20) of repetitions induces strong haemodynamic responses, especially high cardiac afterload and a compensatory heart rate acceleration, which may also create a strong stimulus for cardiopulmonary adaptation. What is the central question of this study? What are the haemodynamic effects of different numbers of repetitions in strength training when investigated independently of intensity? What is the main finding and its importance? Performing an exhaustive number of repetitions (>20) in strength training elicits intense, primarily chronotropic cardiac responses, similar to isometric strength exercises.

Measurement of internal thoracic impedance (ITI) is sensitive and accurate in detecting acute pulmonary edema even at its preclinical stage. We evaluated the suitability of the highly sensitive and noninvasive RS-207 monitor for detecting pleural effusion and for demonstrating increased ITI during its resolution. This prospective controlled study was performed in a single department of internal medicine of a university-affiliated hospital between 2012-2013. One-hundred patients aged 25–96 years were included, of whom 50 had bilateral or right pleural effusion of any etiology (study group) and 50 had no pleural effusion (controls). ITI, the main component of which is lung impedance, was continuously measured by the RS-207 monitor. The predictive value of ITI monitoring was determined by 8 measurements taken every 8 hours. Pleural effusion was diagnosed according to well-accepted clinical and roentgenological criteria. During treatment, the ITI of the study group increased from 32.9±4.2 ohm to 42.8±3.8 ohm (p<0.0001) compared to non-significant changes in the control group (59.6±6.6 ohm, p = 0.24). Prominent changes were observed in the respiratory rate of the study group: there was a decrease from 31.2±4.0 to 19.5±2.4 ohm (35.2%) compared to no change for the controls, and a mean increase from 83.6± 5.3%-92.5±1.6% (13.2%) in O2 saturation compared to 94.2±1.7% for the controls. Determination of ITI for the detection and monitoring of treatment of patients with pleural effusion enables earlier diagnosis and more effective therapy, and can prevent hospitalization and serious complications, such as respiratory distress, and the need for mechanical ventilation. The study is registered at ClinicalTrials.gov NCT01601444.

Accurate and reliable determination of the characteristic points of the impedance cardiogram (ICG) is an important research problem with a growing range of applications in the cardiological diagnostics of patients with heart failure (HF). The shapes of the characteristic waves of the ICG signal and the temporal location of the characteristic points B, C, and X provide significant diagnostic information. On this basis, essential diagnostic cardiological parameters can be determined, such as, e.g., cardiac output (CO) or stroke volume (SV). Although the importance of this problem is obvious, we face many challenges, including noisy signals and the big variability in the morphology, which altogether make the accurate identification of the characteristic points quite difficult. The paper presents an effective method of ICG points identification intended for conducting experimental research in the field of impedance cardiography. Its effectiveness is confirmed in clinical pilot studies.

The accurate detection of fiducial points in the impedance cardiography signal (ICG) has a decisive impact on the proper estimation of diagnostic parameters such as stroke volume or cardiac output. It is, therefore, necessary to find an algorithm that is able to assess their positions with great precision. The solution to this problem is, however, quite challenging with regard to the high sensitivity of the ICG technique to the noise and varying morphology of the acquired signals. The aim of this study is to propose a novel method that allows us to overcome these limitations. The developed algorithm is based on Empirical Mode Decomposition (EMD)—an effective technique for processing and analyzing various types of non-stationary signals. We find high correlations between the results obtained from the algorithm and annotated by an expert. This, in turn, implies that the difference in estimation of the diagnostic-relevant parameters is small, which suggests that the method can automatically provide precise clinical information.

Hypertensive disorders of pregnancy (HDP), including gestational hypertension and preeclampsia, affect up to 10% of pregnancies worldwide and remain a leading cause of maternal and perinatal morbidity and mortality. These conditions are associated with adverse fetal outcomes, including preterm birth, growth restriction, and maternal complications such as stroke, eclampsia, multi-organ dysfunction, and a higher risk of long-term cardiovascular complications. Current management relies largely on intermittent blood pressure monitoring and assessment of symptoms, approaches that provide limited insight into the complex hemodynamic alterations underlying HDP. This narrative review aims to synthesize the available evidence on noninvasive cardiography through thoracic electrical bioimpedance (TEB) as a tool for maternal hemodynamic monitoring in pregnancy, with a focus on hypertensive disorders. Specifically, we (1) describe maternal cardiovascular adaptations in normal gestations and their disruption in HDP, (2) provide an overview of thoracic electrical bioimpedance cardiac output (TEBCO) technology, (3) summarize validation studies in pregnant populations, (4) explore potential clinical applications, including diagnostic support, therapeutic guidance, fluid management and postpartum surveillance, and (5) identify key limitations and research priorities for future practice. Noninvasive cardiography through thoracic electrical bio-impedance is an underutilized tool in the medical field. As an alternative to invasive assessment, TEBCO can identify underlying pathologic hemodynamic changes susceptible to treatment and allow monitoring of hemodynamic trends. The implementation of TEBCO would allow pathophysiologic-based treatments, improve clinical response to therapy, and lead to potential prolongations of pregnancy and cost-savings in healthcare. Current evidence is limited by small sample sizes, device variability, and lack of outcome-based trials. Future research should focus on standardized validation, multicenter studies, and interventional trials to determine whether non-invasive cardiography-guided care can improve maternal and neonatal outcomes.

Accurate cardiac output (CO) estimation from impedance cardiography (ICG) signals is vital for non-invasive monitoring of cardiovascular disorders, including heart failure, arrhythmias, and hemodynamic instability. However, the reliability of ICG-based assessment is often limited by noise artifacts that obscure clinically relevant features. This study introduces a novel three-stage denoising framework integrating Variational Mode Decomposition (VMD), Non-Local Means (NLM), and Discrete Wavelet Transform (DWT) to enhance ICG signal quality for robust CO estimation. The method was validated on the publicly available ReBeatICG dataset, which includes annotated signals from 24 subjects and reflects real-world noise sources such as motion artifacts and baseline drift. Experimental results demonstrate that the proposed VMD-NLM-DWT approach achieves a maximum of 1.2 dB improvement in signal-to-noise ratio (SNR), an average 13% reduction in mean squared error (MSE), and 9% lower percent root mean square difference (PRD) compared to leading two-stage denoising methods. The framework also enhances fiducial point detection (F1-score increase up to 4.4%) and preserves high heart rate variability (HRV) fidelity (correlation coefficient 0.91), with the highest denoising robustness index (DRI) observed across a wide range of noise conditions. These findings confirm that the proposed method outperforms state-of-the-art alternatives in preserving both signal fidelity and clinically significant features under both stationary and non-stationary noise. Furthermore, all performance improvements are statistically validated using paired t -tests and effect size analysis ( , Cohen’s ) and achieves top scores in PSNR and SSIM compared to all baselines. Computational profiling demonstrates feasibility for real-time, continuous cardiac output monitoring in clinical and ambulatory care, supporting its broader application in cardiovascular diagnostics.

BackgroundPediatric hemodialysis (HD) patients have a high incidence of cardiovascular morbidity and mortality. The study aim was to investigate whether impedance cardiography (electrical velocimetry, EV) is suitable as a hemodynamic trend monitoring tool in pediatric patients during HD.MethodsMeasurements by EV were obtained before, during, and after HD in a prospective single-center pediatric observational study. In total, 54 dialysis cycles in four different pediatric patients with end-stage kidney disease on chronic HD were included. EV parameters analyzed were heart rate (HR), stroke volume (SV), stroke volume index (SI), cardiac output (CO), cardiac index (CI), thoracic fluid content (TFC), index of contractility (ICON), stroke volume variation (SVV), variation of ICON (VIC), R-R interval (TRR), pre-ejection period (PEP), left ventricular ejection time (LVET), and systolic time ration (STR). Systemic vascular resistance index (SVRI) was calculated.ResultsEV did measure significant changes in cardiovascular parameters associated with HD. The following parameters increased after HD: HR (9%), SVV (19%), VIC (33%), PEP (8%), and STR (18%). A decrease after HD was measured in SV (18%), SI (18%), CO (10%), CI (10%), TFC (10%), ICON (7%), TRR (7%), LVET (8%), and LVET (8%). SVRI was not affected by HD. The changes were correlated to ultrafiltration. HD cycles without fluid withdrawal also altered cardiovascular parameters.ConclusionsPediatric HD with and without fluid withdrawal changes hemodynamic EV monitoring parameters. Possibly EV may be useful to optimize HD management in pediatric patients.

Background Impedance Cardiography (ICG) is a non-invasive tool for continuous hemodynamic monitoring. Aims of our study were to assess the utility of ICG to evaluate the hemodynamic impact of 6 mg (GL6) vs 8 mg (GL8) levobupivacaine combined with fentanyl in healthy patients undergoing elective cesarean section; secondary, to compare the duration and quality of analgesia and anesthesia. Methods Sixty-two women receiving combined spinal-epidural (CSE) for elective cesarean delivery were randomly allocated to GL6 or GL8 groups. Mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance index (SVRI), heart rate (HR), stroke volume index (SVI) were recorded from Tbaseline to 31 min after CSE by ICG. Sensory and motor blocks, patients and surgeons satisfaction, neonatal data were also recorded. Results Fifteen of 32 patients in GL6 and 15 of 30 patients in GL8 experienced hypotension at T2 vs Tbaseline ( P  < .001) and SVRI reduction ( P  = .035 and P < .001 respectively). MAP, CI and SVRI were always slightly higher in GL6 vs GL8. HR and SVI remained stable until the end of surgery in all patients. Total ephedrine requirements was higher in GL8 ( P  = .010). The onset and offset time of sensory and motor block were similar in both groups, but the number of patients with motor block was lower in GL6 vs GL8 ( P  = .001). Patients and surgeon satisfaction scores, the number of patients needed systemic rescue doses, neonatal data were similar in both groups. Conclusions ICG is a useful noninvasive tool to monitor continuously hemodynamics during cesarean section. The hemodynamic stability, the satisfying sensory block and rapid mobilization provided by low levobupivacaine dose may be particularly advantageous in obstetric patients. Trial registration ClinicalTrials.gov: NCT03170427 . Retrospectively Registered (Date of registration: May 2017).

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