Search Results (15)

Background/Objectives: Spinal anesthesia (SA) for cesarean section and epidural analgesia (EA) for vaginal delivery induce hemodynamic changes that may compromise maternal and fetal safety. In this observational, hypothesis-generating study, we used impedance cardiography (ICG) to characterize maternal hemodynamic responses to EA for labor versus SA for cesarean delivery and to describe hemodynamic profiles associated with commonly used local anesthetic and vasopressor regimens. Methods: In this observational study, 132 women at term were included (52 with epidural analgesia (EA), 80 with spinal anesthesia (SA)). Hemodynamic parameters were measured using the ICON electrical cardiometry monitor (Osypka Medical GmbH). ICON and oscillometric blood pressure (BP) monitoring captured cardiac index (CI), stroke volume (SV), heart rate (HR), systemic vascular resistance index (SVRI), and thoracic fluid content (TFC) at T0 (baseline), approximately 5 and approximately 10 min, skin incision, delivery, and oxytocin administration. Results: CI remained stable and comparable between EA and SA (3.9 ± 0.6 vs. 3.9 ± 0.6 L/min/m²; p = 0.530). SV was higher in EA (85.1 ± 11.3 vs. 78.1 ± 9.7 mL; p < 0.001), whereas HR was higher in SA (92.2 ± 12.9 vs. 85.8 ± 12.5 bpm; p = 0.009). In EA, ropivacaine and bupivacaine showed similar hemodynamic profiles. Within the SA cohort, women managed with phenylephrine infusion had lower CI and HR but higher MAP and SVRI compared with those receiving ephedrine boluses, consistent with the expected pharmacodynamic profiles of these agents. Conclusions: ICG was feasible and provided dynamic, noninvasive estimates of maternal cardiovascular adaptation during obstetric anesthesia. In this non-randomized, exploratory cohort, descriptive differences in hemodynamic profiles between vasopressor strategies were more pronounced than between local anesthetics. Phenylephrine-based management showed a pattern of higher BP and SVRI but lower CI and HR, whereas ephedrine-based management tended to preserve CI through chronotropic effects. Full article

Background: 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. Objective: 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. Conclusions: 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. Full article

Background: Gastric dilatation (GD) and heartworm disease (HW) can significantly impact cardiovascular function, necessitating timely intervention. This study evaluated hemodynamic changes in these conditions using impedance cardiography (ICG), a non-invasive technique for real-time monitoring. Methods: Cardiac parameters were measured using ICG in healthy controls, HW, and GD groups at baseline, during intervention, and post-treatment. Statistical analyses involved repeated measures ANOVA with post hoc comparisons, and relative changes (%) quantified hemodynamic improvements. Results: A significant increase in cardiac index (CI) occurred post-treatment in both HW (+14.71%, p = 0.0102) and GD (+28.53%, p = 0.0336) groups. Cardiac output (CO) exhibited an increasing trend, though without significance (p > 0.05). Mean arterial pressure (MAP) remained stable, although the GD group exhibited an upward trend post decompression (p = 0.1213). Conclusions: Heartworm extraction and gastric decompression induced measurable cardiovascular improvements, with distinct recovery patterns. Non-invasive monitoring effectively captured cardiovascular changes, suggesting its utility as an adjunctive tool in clinical assessment. Full article

(1) Background: The measurement of hemodynamic parameters has proven to be crucial in the treatment of hospitalized heart failure patients, necessitating invasive measurement by right heart catheterization (RHC). The reliability of whole-body impedance cardiography (ICG) among this cohort has not been investigated to date; (2) Methods: The RHC and whole-body ICG examinations measured cardiac output (CO), the cardiac index (CI), total peripheral resistance (TPR), and pulmonary vascular resistance (PVR). To assess the accuracy of the whole-body ICG measurement, bias and precision were calculated as the mean difference and the twofold standard deviation between the average values of measurements; (3) Results: A total of 203 patients were analyzed. No significant bias was observed between the non-invasive CO and CI measurements when compared with the RHC measurements (−0.14 ± 2.56 L/min, p = 0.1; −0.09 ± 1.3 L/min/m², p = 0.06), but a significant bias occurred in the measurement of non-invasive TPR and non-invasive PVR (−1243 ± 3510 dyn × s⁻¹ × cm⁻⁵, p = 0.001; −121 ± 504 dyn × s⁻¹ × cm⁻⁵, p < 0.001); (4) Conclusions: CO and CI can be measured with whole-body ICG among hospitalized CHF patients with acceptable accuracy. The reliability of measuring TPR and PVR should be further investigated. Full article

Background: SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection may be associated with impaired cardiac function, especially in severe cases requiring hospitalization. Impedance cardiography (ICG) is a noninvasive method for assessing cardiac function. It could be useful for the early detection of hemodynamic dysfunction, particularly in patients with a severe course of COVID-19. Aim: This study aimed to analyze and compare the hemodynamic profiles of patients hospitalized with SARS-CoV-2-induced pneumonia to those of a control group. Methods: This prospective, observational, clinical study included 30 hospitalized patients (both men and women, mean age: 48 years) diagnosed with COVID-19 pneumonia (COVID group). Their data were compared to those of a retrospective control group (CG). The study participants were propensity score-matched based on clinical characteristics, including age, blood pressure (BP), and body mass index (BMI). ICG measurements of hemodynamic profiles were performed using a Niccomo device and included heart rate (HR), stroke volume index (SI), cardiac index (CI), velocity index (VI), acceleration index (ACI), Heather index (HI), systemic vascular resistance index (SVRI), and thoracic fluid content (TFC). Results: Patients with COVID-19 showed significantly higher HR (p < 0.0001) and SVRI (p = 0.0003) and lower values for several cardiac function parameters, including SI (p < 0.0001), VI (p < 0.0001), ACI (p = 0.004), and HI (p < 0.0001). Additionally, 11 patients (37%) in the COVID group had a low SI (<35 mL/m²), compared to only 1 patient (3%) in the control group (p < 0.0001). A statistically significant difference in left ventricular ejection fraction (LVEF) was also observed (p < 0.0001), although absolute values remained within the normal range. Conclusions: SARS-CoV-2 infection negatively affects the cardiovascular system, leading to impaired heart function even in low-risk patients. Impedance cardiography may serve as a simple, noninvasive tool for identifying individuals with cardiac dysfunction following COVID-19 pneumonia. Full article

Background/Objectives: Gestational hypertensive disorders (GHD) pose significant maternal and fetal health risks during pregnancy. Preconception physical exercise has been associated with a lower incidence of GHD, but insights into the cardiovascular mechanisms remain limited. This study aimed to evaluate the effect of preconception physical exercise on the complete cardiovascular functions of women at risk for GHD in a subsequent pregnancy. Methods: A non-invasive hemodynamics assessment of arteries, veins, and the heart was performed on 40 non-pregnant women at risk for developing GHD in a subsequent pregnancy. Measurements of an electrocardiogram Doppler ultrasound, impedance cardiography and bio-impedance spectrum analysis were taken before and after they engaged in physical exercise (30–50 min, 3×/week, 4–6 months). Results: After a mean physical exercise period of 29.80 weeks, the total peripheral resistance (TPR), diastolic blood pressure and mean arterial pressure decreased in the total study population, without changing cardiac output (CO). However, in 42% (9/21) of women categorized with high or low baseline CO (>P75 or <P25 resp.), a shift in CO was observed towards the normal reference interquartile range (P25–P75). This was associated with improved hepatic venous and central arterial hemodynamic functions. Similar changes in TPR occurred in 38% (11/29) of women classified as having low or high baseline TPR. Conclusions: As in pregnancy, output- or resistance-dominant cardiovascular profiles already exist prior to conception. This study illustrates that preconception physical exercise shifts high or low CO and/or TPR towards the normal midrange, allowing women at risk for GHD to start a subsequent pregnancy with a more gestation-adaptable cardiovascular system. Full article

Heartworm (HW) disease, caused by Dirofilaria immitis, is a life-threatening ailment in dogs. HW disrupts blood flow and decreases cardiac output (CO). The accurate monitoring of CO during HW extraction is pivotal for patient survival and overall health. Objective: This study aimed to assess the efficacy of using impedance cardiography (ICG) as a non-invasive approach for monitoring CO during interventional HW extraction. Methods: Two cases of HW infections were treated via surgical extraction. The CO and mean arterial pressure (MAP) were monitored using the ICG technique during the anesthesia stabilization, extraction process, and post-extraction phases. Results: In Case 1, the CO increased by 115% post-procedure, and in Case 2, the CO increased by 116%. In contrast, the MAP varied between the two cases. The ICG method provided real-time CO data without major disruptions during the extraction surgery. Conclusion: The ICG technique for CO monitoring during interventional HW extractions is effective. Full article

Impedance cardiography (ICG) is a low-cost, non-invasive technique that enables the clinical assessment of haemodynamic parameters, such as cardiac output and stroke volume (SV). Conventional ICG recordings are taken from the patient’s thorax. However, access to ICG vital signs from the upper-arm brachial artery (as an associated surrogate) can enable user-convenient wearable armband sensor devices to provide an attractive option for gathering ICG trend-based indicators of general health, which offers particular advantages in ambulatory long-term monitoring settings. This study considered the upper arm ICG and control Thorax-ICG recordings data from 15 healthy subject cases. A prefiltering stage included a third-order Savitzky–Golay finite impulse response (FIR) filter, which was applied to the raw ICG signals. Then, a multi-stage wavelet-based denoising strategy on a beat-by-beat (BbyB) basis, which was supported by a recursive signal-averaging optimal thresholding adaptation algorithm for Arm-ICG signals, was investigated for robust signal quality enhancement. The performance of the BbyB ICG denoising was evaluated for each case using a 700 ms frame centred on the heartbeat ICG pulse. This frame was extracted from a 600-beat ensemble signal-averaged ICG and was used as the noiseless signal reference vector (gold standard frame). Furthermore, in each subject case, enhanced Arm-ICG and Thorax-ICG above a threshold of correlation of 0.95 with the noiseless vector enabled the analysis of beat inclusion rate (BIR%), yielding an average of 80.9% for Arm-ICG and 100% for Thorax-ICG, and BbyB values of the ICG waveform feature metrics A, B, C and VET accuracy and precision, yielding respective error rates (ER%) of 0.83%, 11.1%, 3.99% and 5.2% for Arm-IG, and 0.41%, 3.82%, 1.66% and 1.25% for Thorax-ICG, respectively. Hence, the functional relationship between ICG metrics within and between the arm and thorax recording modes could be characterised and the linear regression (Arm-ICG vs. Thorax-ICG) trends could be analysed. Overall, it was found in this study that recursive averaging, set with a 36 ICG beats buffer size, was the best Arm-ICG BbyB denoising process, with an average of less than 3.3% in the Arm-ICG time metrics error rate. It was also found that the arm SV versus thorax SV had a linear regression coefficient of determination (R²) of 0.84. Full article

Hyperprolactinemia in males with prolactin-secreting adenomas, or prolactinomas, may be associated with endothelial dysfunction and co-existing cardiovascular risk factors. As a noninvasive technique of assessing cardiac function, impedance cardiography (ICG) may be useful in the early detection of hemodynamic dysfunction. The aim of the present study was to analyze and compare the hemodynamic profiles of patients with prolactinoma versus controls. A total of 20 men with prolactinoma (PR group) (mean age 43 years) and 20 men from the control group (CG) were evaluated in this prospective, observational comparative clinical study. The study subjects were propensity score-matched in terms of clinical characteristics—age, mean blood pressure [MBP], arterial hypertension [AH] rates, and body mass index [BMI]. ICG assessments of hemodynamic profiles were conducted with the use of a Niccomo™ device and included stroke volume index (SI), cardiac index (CI), systemic vascular resistance index (SVRI), velocity index (VI), acceleration index (ACI), Heather index (HI), and thoracic fluid content (TFC). AH was well-controlled in both study groups (116/76 mmHg PR vs. 119/76 mmHg CG). In comparison with CG patients, ICG revealed PR group patients to have higher rates of high thoracic fluid content (TFC) (>35 1/kOhm; p = 0.035) and lower SI values (<35 mL/m², p = 0.072). There was a convergent tendency towards lower values of other cardiac function parameters (SI, CI, VI, ACI, and HI). Prolactinoma-associated endocrine abnormalities are related to hemodynamic profile alterations, including higher rates of increased TFC and the risk of worsened cardiac function. Full article

Fasting prior to surgery can cause dehydration and alter hemodynamics. This study aimed to determine the impact of a carbohydrate-enriched drink (Nutricia^TM Pre-op^®) on selected hemodynamical parameters, measured in a non-invasive manner. We enrolled 100 healthy volunteers and measured their weight, height, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), thoracic fluid content (TFC), thoracic fluid index (TFCI), stroke volume (SV), stroke volume variation (SVV), stroke index (SI), cardiac output (CO), cardiac index (CI), heather index (HI), systolic time ration (STR), systemic time ratio index (STRI), systemic vascular resistance (SVR), and systemic vascular resistance index (SVRI) by a Niccomo™ device, implementing the impedance cardiography (ICG) method. Measurements were performed at the beginning of the study, and after 10 h and 12 h. We randomly allocated participants to the control group and the pre-op group. The pre-op group received 400 mL of Nutricia™ preOp^®, as suggested in the ERAS guidelines, within 10 h of the study. Student’s t-test or the Mann–Whitney U test were used to compare the two groups, and p < 0.05 was considered significant. We did not observe any changes in hemodynamical parameters, blood pressure, and heart rate between the groups. We have proven that carbohydrate-enriched drink administration did not have a significant impact on the hemodynamical parameters of healthy volunteers. Full article

Cardiography is an indispensable element of health care. However, the accessibility of at-home cardiac monitoring is limited by device complexity, accuracy, and cost. We have developed a real-time algorithm for heart rate monitoring and beat detection implemented in a custom-built, affordable system. These measurements were processed from seismocardiography (SCG) and gyrocardiography (GCG) signals recorded at the sternum, with concurrent electrocardiography (ECG) used as a reference. Our system demonstrated the feasibility of non-invasive electro-mechanical cardiac monitoring on supine, stationary subjects at a cost of $100, and with the SCG–GCG and ECG algorithms decoupled as standalone measurements. Testing was performed on 25 subjects in the supine position when relaxed, and when recovering from physical exercise, to record 23,984 cardiac cycles at heart rates in the range of 36–140 bpm. The correlation between the two measurements had r² coefficients of 0.9783 and 0.9982 for normal (averaged) and instantaneous (beat identification) heart rates, respectively. At a sampling frequency of 250 Hz, the average computational time required was 0.088 s per measurement cycle, indicating the maximum refresh rate. A combined SCG and GCG measurement was found to improve accuracy due to fundamentally different noise rejection criteria in the mutually orthogonal signals. The speed, accuracy, and simplicity of our system validated its potential as a real-time, non-invasive, and affordable solution for outpatient cardiac monitoring in situations with negligible motion artifact. Full article

Cardiac stroke volume (SV) is an essential hemodynamic indicator that can be used to assess whether the pump function of the heart is normal. Non-invasive SV measurement is currently performed using the impedance cardiography (ICG). In this technology, left ventricular ejection time (LVET) is an important parameter which can be determined from the ICG signals. However, the ICG signals are inherently susceptible to artificial noise interference, which leads to an inaccurate LVET measurement and then yields an error in the calculation of SV. Therefore, the goal of the study was to measure LVETs using both the transmission and reflection photoplethysmography (PPG), and to assess whether the measured LVET was more accurate by the PPG signal than the ICG signal. The LVET measured by the phonocardiography (PCG) was used as the standard for comparing with those by the ICG and PPG. The study recruited ten subjects whose LVETs were simultaneously measured by the ICG using four electrodes, the reflection PPG using neck sensors (PPG_neck) and the transmission PPG using finger sensors (PPG_finger). In each subject, ten LVETs were obtained from ten heartbeats selected properly from one-minute recording. The differences of the measured LVETs between the PCG and one of the ICG, PPG_neck and PPG_finger were −68.2 ± 148.6 ms, 4.8 ± 86.5 ms and −7.0 ± 107.5 ms, respectively. As compared with the PCG, both the ICG and PPG_finger underestimated but the PPG_neck overestimated the LVETs. Furthermore, the measured LVET by the PPG_neck was the closest to that by the PCG. Therefore, the PPG_neck may be employed to improve the LVET measurement in applying the ICG for continuous monitoring of SV in clinical settings. Full article

Background: Echocardiography-based programming of conduction delays in cardiac resynchronisation therapy is complex and time-consuming. Impedance cardiography (ICG) may be an alternative method. However, it is unknown whether ICG is sensitive enough to detect haemodynamic changes due to different pacing-induced ventricular activation modes. The aim of this study was to determine the ability of ICG to measure haemodynamic changes during different ventricular pacing modes in patients with a cardiac resynchronisation therapy (CRT). Methods: 18 patients were evaluated. Stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) were measured by means of ICG. Continuous blood pressure (cBP) was recorded with the vascular unloading technique. Haemodynamic measurements of 10-minute-sampling periods, taken in the supine position, were compared during biventricular (BIV), right (RV) and left ventricular (LV) pacing and intrinsic rhythm (IR). Results: One patient was excluded from the analysis (serious haemodynamic deterioration during IR). The age of the study population was 67 ± 10 years (94% male) with a LV ejection fraction of 26 ± 6%. The majority had left-bundle-branch block (82%). Compared to IR, BIV increased SV (58 ± 11 vs 67 ± 12 ml; p = 0.0007), CO (3.6 ± 0.7 vs 4.2 ± 0.8 l/min; p = 0.0007) and reduced TPR (1975 ± 410 vs 1694 ± 390 dyn*s/cm5). cBP remained unchanged during different ventricular pacing modes. Conclusion: ICG is able to detect intraindividual changes of haemodynamic parameters induced by different pacing modes. However, its sensitivity to detect haemodynamic changes through conduction delay variations, as performed for device optimisation, remains unclear. Full article

Exercise cardiography still remains the cornerstone of noninvasive evaluation of functional status of cardiovascular system and is almost uniformly performed after myocardial infarction. The patients after myocardial infarction can be divided into relative high- and low-risk groups for subsequent cardiac events if all information available on the exercise test is used.
Objective. The aim of this study was to evaluate the prognostic significance of the shape of heart rate and systolic blood pressure curves (their dynamic characteristics) during the early exercise testing and after it and to design the prognostic system capable to recognize patients with a high risk of coronary death during 2 years after myocardial infarction.
Material and methods. The submaximal exercise testing within 3 weeks of acute myocardial infarction was performed on 894 patients. Cases of noncardiac deaths or patients subjected to coronary bypass surgery were excluded from the further analysis. At the end of 2 years after myocardial infarction, there were 426 survivors and 42 cases of cardiac death. At 2-year follow-up after infarction in the nonsurvivor group, there were only 42.2% of patients with exercise-induced ST segment depression. This shows that prognostic importance of ST depression is insufficient and demands research of more consistent signs.
Results. The cardiovascular response to exercise was interpreted as transiting process of self-regulation of cardiovascular system, and the new predictive signs were found based on the curves of heart rate and systolic blood pressure during the exercise and after it. The prognostic value of these signs was established. The combined use of both the new predictive signs and usual data of early exercise test shows the high predictive possibility of test – the early cardiac death was predicted in 80% of cases.
Conclusion. The combined use of both, the widely accepted data of early exercise test after myocardial infarction and dynamic characteristics of heart rate and systolic blood pressure, increased the predictive power of the test. Full article

Background and objective. Evaluation of hemodynamics in patients with acute myocardial infarction is crucial. In clinical practice, the comparison of a new measurement technique with an established one is often needed to see whether they agree sufficiently for the new to replace the old. Such investigations are often analyzed inappropriately, notably by using correlation coefficients. Our objective is to present an alternative approach, suggested by D. G. Altman and J. M. Bland, based on graphical techniques and simple calculations, for evaluation of the agreement of two methods – intermittent thermodilution (recognized and accepted as a “gold standard” for hemodynamic monitoring) and impedance cardiography (newly introduced method).
Patients and methods. A total of 34 patients (20 (58.8%) men and 14 (41.2%) women) were investigated according to the study protocol at Kaunas University of Medicine Hospital. A prospective controlled study was designed to compare two different methods – intermittent thermodilution and impedance cardiography – of cardiac output measurement simultaneously in patients with acute myocardial infarction. Statistical analysis was performed with Bland–Altman and linear regression.
Results. A total of 34 paired measurements were carried out in 34 patients at the initiation of hemodynamic monitoring and 30 paired measurements in 32 patients after subsequent improvement or stabilization of clinical status. Correlation coefficient ranged from 0.37 to 0.98.
Conclusions. Bland–Altman analysis is an alternative method for assessing the agreement between two methods of clinical measurement. According to our data, noninvasive technique – impedance cardiography – is a reliable method for hemodynamic monitoring in noncomplicated cases of acute myocardial infarction. Full article