Left Ventricular Cardiac Output Research Articles

Role of fetal cardiac assessment in predicting adverse perinatal outcomes in preterm dichorionic twins

Aim: To investigate the role of the fetal modified myocardial performance index (Mod-MPI) and fetal cardiac output index measurement in predicting adverse perinatal outcomes among preterm dichorionic twins. Materials and Method: This prospective cohort study was conducted at the X Clinic and included 34 dichorionic twin fetuses born early preterm and 40 dichorionic twin fetuses born late preterm. The early preterm group was divided into two according to whether they were admitted to the neonatal intensive care unit (NICU). The groups' cardiac function and Mod-MPI measurements were compared regarding their predictive ability for adverse perinatal outcomes. Results: The Mod-MPI values were similar between the early and late preterm groups (p=0.144). The left ventricular cardiac output Z-score was lower in the preterm group (p=0.014). The Mod-MPI and left ventricular outflow tract-isovolumetric contraction and isovolumetric relaxation times were significantly higher among the newborns admitted to the NICU in the early preterm group (p=0.002, p=0.003, and p=0.001, respectively). Conclusion: Our study suggests that the Mod-MPI measurement can be used to predict adverse perinatal outcomes in dichorionic twin fetuses born in the early preterm period.

The Cardiac and Cerebrovascular Response to Lower Body Negative Pressure in Patients with Postural Orthostatic Tachycardia Syndrome

Introduction: Postural orthostatic tachycardia syndrome (POTS) is characterized by excessive heart rate response upon standing and symptoms that drastically reduce quality of life. Symptoms are often cerebral in nature (e.g., dizziness, headache), however the relationship between the underlying physiology and the symptoms is unknown. We tested the hypothesis that, compared to healthy controls (HC) individuals with POTS would have greater decreases in cardiac, and cerebral hemodynamic function during a simulated orthostatic challenge (lower-body negative pressure; LBNP) measured using magnetic resonance (MR) imaging. Methods: Eleven patients with POTS (17±1yrs; 1 male) and 10 HC (18±2yrs; 1 male) were studied at rest (supine in MRI) and during 20-minutes of -25mmHg LBNP. Symptoms were measured by Vanderbilt Orthostatic Symptom Score (VOSS). Heart rate and blood pressure (BP) were measured using an automated cuff and finger pulse oximeter, respectively. Left and right ventricular volumes, ejection fraction, stroke volume (SV), and cardiac output (Qc) were determined by cardiac MR. Cerebral oxygen utilization (VO2) was calculated as cerebral blood flow (CBF) multiplied by venous oxygen saturation (SVO2), measured by MR phase contrast and susceptomtery-based oximetry in the superior sagittal sinus. Results: At rest, there were no differences between groups for any cardiac hemodynamic measure (p>0.05 for all), however cerebral SvO2 and VO2 were lower in the POTS group (p=0.02 for both). In response to LBNP, patients with POTS had greater VOSS (25±21 vs 5±12; p=0.02). Heart rate increased in response to LBNP (p<0.001), but the increase was not different between groups (HC: +9±8bpm; POTS: +13±11bpm; p=0.35). SV and Qc decreased during LBNP (both, p<0.01), despite no change in mean arterial BP (p=0.13) which did not differ between groups (HC: +9±8mmHg; POTS: 3±6mmHg; p=0.377). Additionally, both left and right ventricular volumes as well as ejection fraction decreased during LBNP (p<0.01 for all). The decreased Qc during LBNP coincided with lower CBF in the superior sagittal sinus (p=0.01) although the response was not different between groups (HC: -17±13ml/min; POTS: -25±32ml/min; p=0.51). Cerebral SvO2 also decreased during LBNP (p=0.03) indicating increased oxygen extraction, resulting in no change in cerebral VO2 during LBNP (p=0.28) and no difference between groups in the VO2 response (HC: -0.2±3.7ml/min; POTS: +1.1±2.0ml/min; p=0.33). Conclusion: In response to a simulated orthostatic challenge (-25mmHg LBNP), patients with POTS do not have impaired cardiac function or cerebral oxygenation despite having a higher symptom score; however, a stronger stimulus may have been necessary to expose differences. Further investigations are needed to elucidate mechanisms of autonomic dysfunction in this population. Women and Children's Health Research Institute. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Comparative Study of Cardiovascular Effects of Selected Pulmonary Vasodilators in Canine Models of Mitral Valve Disease.

Previous reports have shown that various oral pulmonary vasodilators are effective against canine pulmonary hypertension (PH). However, no studies have compared their hemodynamic effects. We aimed to compare the hemodynamic effects of 15 µg/kg beraprost sodium, 1.0 mg/kg sildenafil, and their combination, in dogs with experimentally induced mitral regurgitation. This experimental crossover study evaluated the hemodynamic and functional effects of oral pulmonary vasodilators by application of right-sided heart catheterization and echocardiography. Beraprost significantly decreased pulmonary and systemic vascular resistance. Additionally, beraprost increased right-ventricular stroke volume and left-ventricular cardiac output without worsening left-heart size and left-atrial pressure. The pulmonary vasodilatory effects of sildenafil were stronger, and its systemic vasodilatory effects were weaker than those of beraprost. However, sildenafil significantly increased the left-ventricular volume, left-atrial pressure indicator, and right-ventricular cardiac output. Combination therapy resulted in the strongest pulmonary and systemic vasodilating effects without worsening the left-heart size and left-atrial pressure indicators. Both beraprost and sildenafil were effective against canine PH; however, sildenafil was associated with the risk of worsening left-heart loading. Combination therapy with beraprost and sildenafil synergistically dilated pulmonary and systemic vessels, indicating a more potent treatment option for severe PH cases.

Maternal tadalafil treatment does not increase uterine artery blood flow or oxygen delivery in the pregnant ewe.

Increasing placental perfusion (PP) could improve outcomes of growth-restricted fetuses. One way of increasing PP may be by using phosphodiesterase (PDE)-5 inhibitors, which induce vasodilatation of vascular beds. We used a combination of clinically relevant magnetic resonance imaging (MRI) techniques to characterize the impact that tadalafil infusion has on maternal, placental and fetal circulations. At 116-117 days' gestational age (dGA; term, 150days), pregnant ewes (n=6) underwent fetal catheterization surgery. At 120-123dGA ewes were anaesthetized and MRI scans were performed during three acquisition windows: a basal state and then ∼15-75min (TAD 1) and ∼75-135min (TAD 2) post maternal administration (24mg; intravenous bolus) of tadalafil. Phase contrast MRI and T2 oximetry were used to measure blood flow and oxygen delivery. Placental diffusion and PP were assessed using the Diffusion-Relaxation Combined Imaging for Detailed Placental Evaluation-'DECIDE' technique. Uterine artery (UtA) blood flow when normalized to maternal left ventricular cardiac output (LVCO) was reduced in both TAD periods. DECIDE imaging found no impact of tadalafil on placental diffusivity or fetoplacental blood volume fraction. Maternal-placental blood volume fraction was increased in the TAD 2 period. Fetal and were not affected by maternal tadalafil administration. Maternal tadalafil administration did not increase UtA blood flow and thus may not be an effective vasodilator at the level of the UtAs. The increased maternal-placental blood volume fraction may indicate local vasodilatation of the maternal intervillous space, which may have compensated for the reduced proportion of UtA .

Effects of Continuous Precision Nursing Model on Knowledge, Attitudes, and Practices (KAP) Behavior and Cardiac Function in Patients after Percutaneous Coronary Angiography and Stent Implantation

Objective: To explore the impact of a continuous precision nursing model on patients’ Knowledge, Attitudes, and Practices (KAP) and cardiac function during the nursing process of patients undergoing percutaneous coronary angiography and stent implantation. Methods: Ninety patients who underwent percutaneous coronary angiography and stent implantation in our hospital from April 2022 to April 2023 were selected and randomly divided into the control group (45 cases), in which routine nursing support was carried out during the treatment process, and the observation group (45 cases), in which continuous precision nursing model was carried out during the treatment process. Comparisons were made between the two groups of patients on their KAP, cardiac function, and quality of life during recovery. Results: There was no difference in the left ventricular ejection fraction (LVEF), cardiac output (CO), and cardiac index (CI) levels before intervention. After the intervention, the levels of cardiac function in the observation group were higher than those of the control group (P < 0.05). There was no difference in the Exercise of Self-Care Agency (ESCA) self-care ability scale scores before the intervention. After the intervention, the observation group had higher ESCA scores than the control group (P < 0.05). Conclusion: Implementation of a continuous precision nursing model in the care of patients undergoing percutaneous coronary angiography and stent implantation improved the patient’s cardiac function, and KAP, and promoted recovery.

Effect of furosemide combined with continuous renal replacement therapy on cardiorenal function and inflammatory response in patients with chronic renal and heart failure after hemodialysis

Purpose: To determine the effect of furosemide combined with continuous renal replacement therapy (CRRT) on cardiorenal function and inflammatory response in patients with chronic renal failure (CRF) and heart failure after hemodialysis. 
 Methods: 130 patients with both CRF and heart failure, who underwent hemodialysis at the Second Hospital Affiliated to Hainan Medical College, China, from October 2020 to October 2022 were recruited as study subjects. They were randomly divided into two groups, with control group administered the Continuous Renal Replacement Therapy (CRRT) while study group received furosemide in addition. The study assessed the clinical outcomes, cardiorenal function and inflammatory factors before and after treatment. Additionally, adverse reactions during treatment were documented for both groups. 
 Results: Study group exhibited a significantly higher (p < 0.001) total response rate compared to control group. Post-treatment, both groups displayed significant increases (p < 0.05) in left ventricular ejection fraction, cardiac output and stroke volume, with study group showing significantly superior results (p < 0.05). Furthermore, post-treatment, both groups experienced significant reductions (p < 0.05) in serum creatinine, blood urea nitrogen, and 24-hour urinary protein levels, with study group displaying significantly lower levels (p < 0.05). Additionally, the interleukin-6, interleukin-1β and tumor necrosis factor-α levels decreased significantly in both groups post-treatment, with study group exhibiting significantly lower levels (p < 0.05). There was no significant difference in adverse reaction incidence between the two groups. 
 Conclusion: Furosemide combined with CRRT significantly improves cardiorenal function and reduces inflammatory response in patients with CRF and heart failure after hemodialysis. Future research could optimize dosage and administration protocols, explore long-term effects and assess applicability in diverse patient populations.

Characteristics and changes of cardiac injury with age in children of Duchenne muscular dystrophy: a prospective cohort study

Objective: To explore the characteristics and changes of cardiac injury with age in Duchenne muscular dystrophy (DMD) and its clinical significance. Methods: A prospective cohort study was conducted. The 215 patients diagnosed with DMD in West China Second Hospital from January 2019 to November 2022 and aged from 6 to 18 years were enrolled. Their clinical data, myocardial injury markers, routine electrocardiogram, cardiac magnetic resonance (CMR) and echocardiography were collected. The patients were divided into five age groups: 6-<8, 8-<10, 10-<12, 12-<14 and 14-18 years of age, and matched with healthy boys respectively. Independent sample t test or Mann-Whitney U test was used to compare the clinical data and CMR indexes between DMD patients and controls in all age subgroups, and to compare the value of left ventricular ejection fraction (LVEF) measured by echocardiography and CMR in each subgroup of DMD patitents. Pearson correlation analysis or Spearman correlation analysis was used to explore the relation between the CMR indexes and age in DMD patients. Results: A total of 215 patients with DMD (all male) and 122 healthy boys were included in the study. There were 75 DMD patients and 23 controls in 6-<8 years of age group, 77 DMD and 28 controls in 8-<10 years of age group, 39 DMD and 23 controls in 10-<12 years of age group, 10 DMD and 31 controls in the 12-<14 years of age group, and 14 DMD and 17 controls in 14-18 years of age group. In the DMD patients, the older the age, the lower the levels of creatine kinase (CK) and creatine kinase isoenzyme (CK-MB). In the 6-<8 years of age group, the CK level was 10 760 (7 800, 15 757) U/L, while in the group of 14-18 years of age, it was 2 369 (1 480, 6 944) U/L. As for CK-MB, it was (189±17) μg/L in the 6-<8 years of age group and (62±16) μg/L in the 14-18 years of age group. Cardiac troponin I remained unchanged in <12 years of age groups, but significantly increased in 12-<14 years of age group, reaching the highest value of 0.112 (0.006, 0.085) μg/L. In the DMD patients, the older the age, the higher the proportion of abnormal electrocardiogram (ECG). In the 6-<8 years of age group, the proportion is 29.3% (22/75), while in the 14-18 years of age group, it was 10/14. Correlation analysis showed that the left ventricular end-diastolic volume index was positively related with age (r=0.18, P=0.015), and the left ventricular stroke volume index and cardiac output index were negatively related with age (r=-0.34 and -0.31, respectively, both P<0.001). In the DMD patients, the older the age, the lower LVEF, with the LVEF decreasing to (49.3±3.1)% in the 14-18 years of age group. The LVEF of DMD cases was significantly lower than that of controls in the age subgroups of 8-<10, 10-<12, 12-<14 and 14-18 years of age groups ((57.9±5.2) % vs. (63.6±0.8)%, 60.7% (55.9%, 61.9%) vs. 63.7% (60.2%, 66.0%), 57.1% (51.8%, 63.4%) vs. 62.1 % (59.5%, 64.5)%, (49.3±3.1) % vs. (61.6±1.3)%, respectively; all P<0.01). In the DMD patients, the older the age, the higher the proportion of positive late gadolinium enhancement (LGE). In the 6-<8 years of age group, it was 22% (11/51), in the 12-<14 years of age group, it was 13/14, and in the 14-18 years of age group, all DMD showed positive LGE. The value of LVEF of DMD cases measured by echocardiography was significantly higher than that measured by CMR in 6-<8 years of age group and 8-<10 years of age group (63.2% (60.1%, 66.4%) vs. 59.1 % (55.4%, 62.9%), and (62.8±5.2) % vs. (57.9±5.2)%, all P<0.001). Conclusion: DMD patients develop cardiac injury in the early stage of the disease, and the incidence of cardiac damage gradually increases with both age and the progression of disease.

The Post-Flight Rehabilitation Program for Astronauts in Health Resort: Case Report Series

INTRODUCTION. The prospects for studying deep space are associated with the development of methods and programs for restoring the body of astronauts after flights. In this case, an important role is given to the implementation of aspects of restoring the functions of the nervous system of astronauts at the 2nd stage of post-flight rehabilitation (PFR) in Health Resort.&#x0D; AIM. To develop a program of rehabilitation for cosmonauts in Health Resort (stage 2 of PFR), aimed at restoring the functions of the nervous system.&#x0D; MATERIALS AND METHODS. The study involved 5 cosmonauts. Diagnostics included assessment of psychological and psychophysiological parameters and properties of the nervous system, the functional state of the autonomic nervous system. The rehabilitation program included: intake of mineral water “Slavyanovsky”, carbon dioxide-hydrogen sulfide baths, baro-, halo-, inhalation and climate therapy, a course of 5 sessions of neurofeedback on the β-rhythm of the brain. The duration of PFR was 21 days, procedures were carried out every other day.&#x0D; RESULTS AND DISCUSSION. An assessment of heart rate variability revealed the predominance of the influence of the parasympathetic division. After the rehabilitation course, there was a decrease in the stiffness index. There was a positive trend towards normalization of indicators: blood saturation, reflection index, a marker of left ventricular function, cardiac output, blood pressure and oxygen absorption from the microcirculatory system. The dynamics of biofeedback training indicators based on the β-rhythm indicated the orderliness and synchronization of the electroencephalogram (EEG) rhythm signal; an increase in the efficiency of mental work was also revealed.&#x0D; CONCLUSION. The results obtained indicate the positive impact of the developed program of the 2nd stage of PFR, as a result of which a positive dynamics of indicators of autonomic regulation, central hemodynamics, improvement of mental performance, orderliness and synchronization of the EEG rhythm signal.

Multi-modal assessment of a cardiac stem cell therapy reveals distinct modulation of regional scar properties

BackgroundThe initial idea of functional tissue replacement has shifted to the concept that injected cells positively modulate myocardial healing by a non-specific immune response of the transplanted cells within the target tissue. This alleged local modification of the scar requires assessment of regional properties of the left ventricular wall in addition to commonly applied measures of global morphological and functional parameters. Hence, we aimed at investigating the effect of cardiac cell therapy with cardiovascular progenitor cells, so-called cardiac induced cells, on both global and regional properties of the left ventricle by a multimodal imaging approach in a mouse model.MethodsMyocardial infarction was induced in mice by ligation of the left anterior descending artery, the therapy group received an intramyocardial injection of 1 × 106 cardiac induced cells suspended in matrigel, the control group received matrigel only. [18F]FDG positron emission tomography imaging was performed after 17 days, to assess regional glucose metabolism. Three weeks after myocardial infarction, cardiac magnetic resonance imaging was performed for morphological and functional assessment of the left ventricle. Following these measurements, hearts were excised for histological examinations.ResultsCell therapy had no significant effect on global morphological parameters. Similarly, there was no difference in scar size and capillary density between therapy and control group. However, there was a significant improvement in contractile function of the left ventricle – left ventricular ejection fraction, stroke volume and cardiac output. Regional analysis of the left ventricle identified changes of wall properties in the scar area as the putative mechanism. Cell therapy reduced the thinning of the scar and significantly improved its radial contractility. Furthermore, the metabolic defect, assessed by [18F]FDG, was significantly reduced by the cell therapy.ConclusionOur data support the relevance of extending the assessment of global left ventricular parameters by a structured regional wall analysis for the evaluation of therapies targeting at modulation of healing myocardium. This approach will enable a deeper understanding of mechanisms underlying the effect of experimental regenerative therapies, thus paving the way for a successful translation into clinical application.

Cardiac remodelling in non-alcoholic fatty liver disease in the general population.

Non-alcoholic fatty liver disease (NAFLD) is associated with increased risk for cardiovascular disease. Our study investigates the contribution of NAFLD to changes in cardiac structure and function in a general population. One thousand ninety-six adults (49.3% female) from the Study of Health in Pomerania underwent magnetic resonance imaging including cardiac and liver imaging. The presence of NAFLD by proton density fat fraction was related to left cardiac structure and function. Results were adjusted for clinical confounders using multivariable linear regression model. The prevalence for NAFLD was 35.9%. In adjusted multivariable linear regression models, NAFLD was positively associated with higher left ventricular mass index (β = 0.95; 95% confidence interval (CI): 0.45; 1.45), left ventricular concentricity (β = 0.043; 95% CI: 0.031; 0.056), left ventricular end-diastolic wall thickness (β = 0.29; 95% CI: 0.20; 0.38), left atrial end-diastolic volume index (β = 0.67; 95% CI: 0.01; 1.32) and inversely associated with left ventricular end-diastolic volume index (β = -0.78; 95% CI: -1.51; -0.05). When stratified by sex, we only found significant positive associations of NAFLD with left ventricular mass index, left atrial end-diastolic volume index, left ventricular cardiac output and an inverse association with global longitudinal strain in women. In contrast, men had an inverse association with left ventricular end-diastolic volume index and left ventricular stroke volume. Higher liver fat content was stronger associated with higher left ventricular mass index, left ventricular concentricity and left ventricular end-diastolic wall thickness. NAFLD is associated with cardiac remodelling in the general population showing sex specific patterns in cardiac structure and function.

Efficacy and prognostic impact of Pericarpium Trichosanthis injection combined with nicorandil for intractable angina pectoris in elderly patients: A retrospective study.

Coronary artery disease (CAD) is a leading cause of global cardiovascular mortality. Refractory angina pectoris, a manifestation of CAD, requires effective drug treatments. Pericarpium Trichosanthis injection, a traditional Chinese medicine, improves cardiovascular symptoms, while nicorandil alleviates spasms and angina. Both have potential in treating CAD. To investigate the therapeutic effects of combining Pericarpium Trichosanthis injection and nicorandil in elderly patients suffering from refractory angina caused by coronary heart disease. A retrospective analysis was conducted on the data of 130 patients diagnosed with refractory coronary heart disease. Based on the different treatment regimens administered during hospitalization, the patients were divided into a control group (58 cases) and a study group (72 cases). The control group received conventional treatment, which included aspirin, statins, and nitrate vasodilators. In addition to the conventional medication, the study group received a combination treatment of Pericarpium Trichosanthis injection and nicorandil. After treatment, the study group showed significantly higher left ventricular ejection fraction and cardiac output, and lower brain natriuretic peptide and C-reactive protein levels compared to the control group. The study group also exhibited improvements in angina, quality of life, exercise endurance, and lipid profiles. Multivariate logistic regression analysis revealed a relationship of lipid levels and heart function with the combined treatment. Some patients in the study group experienced headaches during treatment, but no significant adverse reactions were observed. Follow-up showed that the treatment was well-tolerated, with no drug-related adverse reactions detected. Combination of Pericarpium Trichosanthis injection and nicorandil is more effective than conventional treatment in improving symptoms and heart function in elderly patients with refractory angina pectoris.

Effect of flow reduction surgery in a patient with high flow arteriovenous fistula with aortic dissection using 4D flow magnetic resonance imaging: A case report.

This study aimed to investigate cardiovascular function in a patient with high-flow arteriovenous fistula (AVF) who underwent aortic dissection (AD) using four-dimensional (4D) flow magnetic resonance imaging (MRI) as well as analyze the effect of flow reduction surgery on AD. On March 12, 2017, a 60-year-old woman underwent emergency surgery for AD. After that, she experienced acute kidney injury, and hemodialysis was initiated. On April 24, 2017, a left brachiocephalic arteriovenous fistula (AVF) was created to facilitate her dialysis. However, after 5 years, the patient presented with a high-flow AVF, and a flow reduction surgery was performed on March 11, 2022. To evaluate the procedure's effectiveness, we measured the changes in left ventricular (LV) function and blood flow in the aorta and vascular access before and after surgery using 4D flow MRI. Notable changes were observed in LV function, blood flow in the aorta before and after the surgery, and maximum velocity and flow volume after surgery. During the 6-month follow-up after the surgery, the maximum velocity and flow volume in the aorta and vascular access were reduced; also, indicators such as LV volume, cardiac output, cardiac index, and LV mass were improved. In patients with high-flow AVF, flow reduction surgery should be considered as it may improve LV function and reduce the risk of AD recurrence by lowering the flow volume of the aorta.

The emerging concept of glycocalyx damage as the trigger of heart failure onset and progression

The suppression of adrenergic and renin-angiotensin-aldosterone system (RAAS) activity, exaggerated due to hypoperfusion-related hypoxia and/or sodium retention, is crucial for drugs’ efficacy in heart failure (HF). Both, insufficient oxygenation and excess sodium impair the glycocalyx-dependent microcroperfusion and peripheral metabolism, therefore enhancing the adrenergic and RAAS activity. The local renal and pulmonary RAAS activity and hypoxia increase sodium retention. Interstitial sodium accumulation activates interstitial inflammation and coagulation disorders that further diminish glycocalyx-supported microperfusion and peripheral metabolism. The main trigger of glycocalyx damage in reduced ejection fraction (EF) HF is hypoxia; whereas, in HF preserved EF sodium retention prevails; both stimulate left ventricular (LV) cardiac output (CO), however, impair microperfusion and metabolic heat production. Infrared-dependent, surface-induced flow (SIF) and diamagnetic properties of oxygenated haemoglobin; both improve non-Newtonian blood flow. Therefore, the temperature-driven SIF augments the deoxygenated erythrocytes' flow, while the pulmonary oxygenation of haemoglobin, by diamagnetic properties, enables frictionless erythrocytes’ flow in the oxygenated blood compartments complementing the cardiac function in HF.

Assessing cardiac power output values in a healthy adult population.

Cardiac power output (CPO), which combines pressure and flow capacities, directly measures the heart's pumping capability. It is proposed as a superior alternative to ejection fraction in assessing cardiac function. However, there is a lack of data on CPO in healthy individuals, prompting a study to determine the cardiac power output in healthy adults in the Iranian population.This cross-sectional descriptive study investigated cardiac power in a sample of healthy individuals. Participants were recruited from healthy individuals referred to the Echocardiography department using convenience sampling.In this study, we examined the echocardiographic parameters in 173 individuals, of which 52% were men. Men exhibited significantly higher values for stroke volume, cardiac output, and cardiac power output (CPO) in both ventricles, as well as larger body surface area (BSA) and systemic mean arterial pressure (MAP), compared to women. Individuals under the age of 40 had significantly higher BSA and right ventricular cardiac output compared to those aged 40 or above. Multivariate analysis revealed that MAP, left ventricular (LV) cardiac output, LVCPO, pulmonary MAP, right ventricular (RV) CPO, and RV cardiac power index (CPI) were significant predictors of LVCPI changes.Our findings emphasize the importance of cardiac power output as a comprehensive measure of cardiac function, complementing the traditional use of ejection fraction. Further research is warranted to validate these results, establish accurate reference ranges, and explore the clinical implications of cardiac power output in various patient populations.

Longitudinal Strain vs. Conventional Echocardiographic Parameters in the First Week of Life in Healthy Term Newborns.

The first week of life is characterized by substantial alterations in hemodynamic conditions. Changes in myocardial contractility will reflect these changes. We aimed to assess right and left ventricular function on the third and seventh days of life in 50 healthy term newborns. To assess myocardial function, we used speckle tracking echocardiography. Pulsed-wave tissue Doppler imaging, M-mode, Doppler and pulsed-wave Doppler were also used to assess ventricular function. We found a significant increase in both right and left longitudinal strain and an increase in systolic and diastolic tissue Doppler velocities, whereas most other parameters remained unchanged. At both time points, the measured parameters were significantly greater for the right ventricle, but the changes with time were similar for both ventricles. We also found an increase in right ventricular outflow tract acceleration time as an indirect sign of decreasing pulmonary vascular resistance and an increase in systolic blood pressure, pointing to increasing systemic vascular resistance. Together with a decreasing proportion of patients with patent ductus arteriosus, the estimated left ventricular cardiac output decreased and right ventricular cardiac output increased but not to a statistically significant degree. In conclusion, the results of our study show how different echocardiographic techniques capture hemodynamic changes and changes in myocardial contractility and compliance. Both longitudinal strain and tissue Doppler imaging parameters seem to offer greater sensitivity in comparison with conventional echocardiographic parameters.

Fetal cardiac magnetic resonance imaging of the descending aorta in suspected left-sided cardiac obstructions.

Severe left-sided cardiac obstructions are associated with high morbidity and mortality if not detected in time. The correct prenatal diagnosis of coarctation of the aorta (CoA) is difficult. Fetal cardiac magnetic resonance imaging (CMR) may improve the prenatal diagnosis of complex congenital heart defects. Flow measurements in the ascending aorta could aid in predicting postnatal CoA, but its accurate visualization is challenging. To compare the flow in the descending aorta (DAo) and umbilical vein (UV) in fetuses with suspected left-sided cardiac obstructions with and without the need for postnatal intervention and healthy controls by fetal phase-contrast CMR flow. A second objective was to determine if adding fetal CMR to echocardiography (echo) improves the fetal CoA diagnosis. Prospective fetal CMR phase-contrast flow in the DAo and UV and echo studies were conducted between 2017 and 2022. A total of 46 fetuses with suspected left-sided cardiac obstructions [11 hypoplastic left heart syndrome (HLHS), five critical aortic stenosis (cAS), and 30 CoA] and five controls were included. Neonatal interventions for left-sided cardiac obstructions (n = 23) or comfort care (n = 1 with HLHS) were pursued in all 16 fetuses with suspected HLHS or cAS and in eight (27%) fetuses with true CoA. DAo or UV flow was not different in fetuses with and without need of intervention. However, DAo and UV flows were lower in fetuses with either retrograde isthmic systolic flow [DAo flow 253 (72) vs. 261 (97) ml/kg/min, p = 0.035; UV flow 113 (75) vs. 161 (81) ml/kg/min, p = 0.04] or with suspected CoA and restrictive atrial septum [DAo flow 200 (71) vs. 268 (94) ml/kg/min, p = 0.04; UV flow 89 vs. 159 (76) ml/kg/min, p = 0.04] as well as in those without these changes. Adding fetal CMR to fetal echo predictors for postnatal CoA did not improve the diagnosis of CoA. Fetal CMR-derived DAo and UV flow measurements do not improve the prenatal diagnosis of left-sided cardiac obstructions, but they could be important in identifying fetuses with a more severe decrease in blood flow across the left side of the heart. The physiological explanation may be a markedly decreased left ventricular cardiac output with subsequent retrograde systolic isthmic flow and decreased total DAo flow.

Reduced in utero substrate supply decreases mitochondrial abundance and alters the expression of metabolic signalling molecules in the fetal sheep heart.

Babies born with fetal growth restriction (FGR) are at higher risk of developing cardiometabolic diseases across the life course. The reduction in substrate supply to the developing fetus that causes FGR not only alters cardiac growth and structure but may have deleterious effects on metabolism and function. Using a sheep model of placental restriction to induce FGR, we investigated key cardiac metabolic and functional markers that may be altered in FGR. We also employed phase-contrast magnetic resonance imaging MRI to assess left ventricular cardiac output (LVCO) as a measure of cardiac function. We hypothesized that signalling molecules involved in cardiac fatty acid utilisation and contractility would be impaired by FGR and that this would have a negative impact on LVCO in the late gestation fetus. Key glucose (GLUT4 protein) and fatty acid (FATP, CD36 gene expression) substrate transporters were significantly reduced in the hearts of FGR fetuses. We also found reduced mitochondrial numbers as well as abundance of electron transport chain complexes (complexes II and IV). These data suggest that FGR diminishes metabolic and mitochondrial capacity in the fetal heart; however, alterations were not correlated with fetal LVCO. Overall, these data show that FGR alters fetal cardiac metabolism in late gestation. If sustained ex utero, this altered metabolic profile may contribute to poor cardiac outcomes in FGR-born individuals after birth. KEY POINTS: Around the time of birth, substrate utilisation in the fetal heart switches from carbohydrates to fatty acids. However, the effect of fetal growth restriction (FGR) on this switch, and thus the ability of the fetal heart to effectively metabolise fatty acids, is not fully understood. Using a sheep model of early onset FGR, we observed significant downregulation in mRNA expression of fatty acid receptors CD36 and FABP in the fetal heart. FGR fetuses also had significantly lower cardiac mitochondrial abundance than controls. There was a reduction in abundance of complexes II and IV within the electron transport chain of the FGR fetal heart, suggesting altered ATP production. This indicates reduced fatty acid metabolism and mitochondrial function in the heart of the FGR fetus, which may have detrimental long-term implications and contribute to increased risk of cardiovascular disease later in life.

Increased cardiac output and left ventricular contractility in pigs paced with vs. without restored respiratory sinus arrhythmia - proof of principle of a newly developed pacing device

Abstract Background Heart rate variability (HRV) correlates with the severity and mortality of heart failure. Respiratory sinus arrhythmia (RSA) is defined by the dynamic increase and decrease in heart rate between breaths. Restoration of RSA might be beneficial in patients with heart failure and/or patients in need of permanent pacing. Purpose The aim of this translational, proof-of-principle study was to investigate the effect of pacing with or without RSA using a newly designed pacing device on the left ventricular contractility and cardiac output. Methods The project was initiated with the aim of designing a new pacing device capable of restoring RSA in paced hearts with the help of lung inflation sensors. Neuronal networks were designed to reconstruct the human brain using ultra-low energy-consuming technology. The lung inflation sensor fed the detected inspiration data back to the pacing device, which paced the heart via pacing leads (DDD) in the right atrium and ventricle. In total, 5 intubated but spontaneously breathing landrace pigs were paced without RSA (fixed-rate pacing) and with restored RSA. Stroke volume and cardiac output were measured by echocardiography (diameter of left ventricular outflow tract and velocity time integral measured by pulsed wave doppler averaged over three heart beats). Preload-independent cardiac contractility was measured via a pressure-volume loop catheter in the left ventricle during occlusion of the inferior vena cava. Fig. 1 indicates the setup of the trial. The trials were conducted according to the relevant rules (NIH Publication no. 85-23 revised 1985) and in accordance with national law. Results Echocardiography (n=5) showed a mean left ventricular outflow tract diameter of 21 ± 0.1 mm. The mean intrinsic heart rate was 87 ± 14 bpm, and the mean paced heart rate was 104 ± 5 bpm in the pigs (65 ± 3 kg). The main outcomes are displayed in Fig. 2: The left ventricular stroke volume increased by 11ml (+21%, p=0.036) with 100% RSA compared to pacing without RSA, while cardiac output increased by 1.14 l/min (+21%, p=0.037). The pressure volume area is proportional to the total myocardial oxygen consumption and decreased by 6234 mmHg*ml (-39%, p=0.004). Cardiac efficiency represents the relative amount of blood being pumped consuming one unit energy and increased by 0.163 (+72%, p=0.033). End-systolic pressure volume relationship demonstrated a non-significant increase by 0.183 mmHg/ml (+45%, p=0.25). Parameters of diastolic function (Tau) did not differ between the groups. Conclusion Restoration of RSA by our newly developed pacing device significantly improved the cardiac contractility/output in our proof-of-principle large animal translational model. Chronic trials will be required to definitively confirm the positive effects of RSA on cardiac remodeling.Fig. 1: Set-up of the animal trials.Fig. 2: Main results (mean/std error)

Left atrial appendage geometry and function using transesophageal three-dimensional echocardiography in atrial fibrillation: a new approach to characterize left atrial thrombogenic milieu

Abstract Background Little data is available on the evaluation of left atrial appendage (LAA) geometry and function using three-Dimensional (3D) transoesophageal echocardiography (TEE). Purpose We hypothesized that 3D LAA geometry evaluated using dedicated TEE software could be integrated in the evaluation of the thromboembolic milieu in patients hospitalized for atrial fibrillation (AF). Methods We prospectively studied 206 hospitalized patients with AF with two-dimensional transthoracic echocardiography (TTE) and 3D TEE of the LAA within 24 hours of admission. 3D parameters were analysed off-line using Tomtec software (4D Cardio-View, Generic Volume, Philips) (Figure 1). Patients were divided into two groups according to the presence (n = 35) or absence (n = 171) of LAA sludge/thrombus on admission. Results Patients with LAA sludge/thrombus had more frequently a history of heart failure together with higher values of BNP, CRP and hemoglobin. These patients received less frequently angiotensin II receptor antagonist treatment on admission. Concerning the echocardiographic characteristics, patients with LAA sludge/thrombus exhibited higher left atrial (LA) volume, lower left ventricular ejection fraction (LVEF) and cardiac output. In the 2D TEE study they had lower LAA emptying and filling flow velocities compared to those without sludge/thrombus. 3D TEE showed overall higher 3D end-systolic (ES) and end-diastolic (ED) LAA measurements (ostium area, length, volume), and more frequently the absence of a chicken wing morphology. There were no intergroup differences regarding the number of LAA lobes (Table 1). Conclusion 3D characterization of LAA geometry and function depicts a degree of appendage remodeling in AF that appears to be associated with the degree of thrombogenicity. Further investigation is needed to determine the impact of this remodeling on outcomes in these patients.

Abstract 17334: Association of BIN1 Deletion With Electrical and Structural Remodeling in a Transgenic BIN1 KO Mouse Model of Heart Failure-Novel Option for Effective Therapy Using VK-II-86

Introduction: Cardiac deletion of Bridging Integrator 1 (BIN1) membrane protein produces an age-related cardiomyopathy in mice. Our hypothesis was to determine whether electrical accompanies this structural remodeling and examine the utility of VK-II-86, a structural analog of carvedilol with minimum β-blocking activity, as a potential antiarrhythmic therapeutic strategy. Methods: A cardiac-specific transgenic BIN1 KO mouse was employed. Structural and electrical cardiac changes were assessed using echocardiography and EKG (Visual Sonics-Vevo Heart Image). Murine ventricular cardiomyocytes were studied using patch-clamp techniques to examine changes in ion channel function and to study the effects of VK-II-86 on the action potential (AP). Results: Loss of BIN1 (KO) significantly reduced Left Ventricular Ejection Fraction (LVEF) and Cardiac Output (CO) when compared to WT mice, with a relative reduction of nearly 20% and 35% in EF and CO, respectively. Heterozygotic mice (HET) also exhibited significant reduction in EF and CO compared to WT mice. Loss of BIN1 (KO and HET) significantly prolonged the QT interval on surface ECG by approximately 15%. This finding correlates with the increase in AP duration (APD) demonstrated in ventricular cardiomyocytes using current clamp. BIN1 deficient hearts displayed significant reduction in expression of I to , I K1 and peak I Na (80%, 40% and 20% respectively) as well as augmented expression of late I Na (50%). This electrical remodeling is likely responsible for the increased expression of early (EAD) and late (DAD) afterdepolarization observed in APs. In BIN1 deficient ventricular cardiomyocytes, the addition of 1 μM VK-II-86 prevented the development of APD prolongation and suppressed EAD and DAD development. Conclusions: Our study adds to the understanding the role of BIN1. We demonstrate the first-time electrical remodeling in the form of QT and APD prolongation associated with BIN1 deficiency, due to reduced I to and I K1 and increase in late I Na , an increase in EAD and DAD events. Additionally, VK-II-86 is shown to normalize APD in isolated cardiomyocytes and suppress afterdepolarization events, making it a potentially novel and effective therapeutic strategy in HF associated with BIN1 deficiency.