New insight into the intraventricular pressure gradient as a sensitive indicator of diastolic cardiac dysfunction in patients with childhood cancer after anthracycline therapy

Intraventricular Pressure Difference Estimation based on Blood Speckle Tracking - Invasive Validation and Early Clinical Application

AIMS

Ventricular relaxation creates an intraventricular pressure difference (IVPD) and resultant diastolic suction. Non-invasive estimation by echocardiographic techniques would allow to clinically evaluate IVPD as an important component of diastolic functional assessment. The aims of the current study were to evaluate the accuracy of IVPD estimation based on Blood Speckle Tracking (BST) echocardiography compared to invasive pressure measurements and to clinically apply the method in children with univentricular hearts (UVH) and controls.

METHODS AND RESULTS

The accuracy of BST-based IVPD-estimates was assessed in an open-chest porcine model, comparing BST-based IVPD with simultaneous repeated invasive pressure measurements in six pigs using micromanometer catheters. BST-based IVPD assessment during early diastolic filling was performed in 83 healthy controls and 44 patients with UVH and compared between the groups.The validation in pigs included 103 measurements, demonstrating a mean difference of -0.01 mmHg (p=0.33) and high correlation (r = 0.95, p-value < 0.001) between IVPD from BST (-1.31 ± 0.28 mmHg) and invasive measurements (-1.30 ± 0.31 mmHg). In the pediatric patients, age range 6 months-17.76 years, feasibility was 93.9 % in controls and 88.6% in UVH patients. Median IVPD was significantly higher in controls compared to UVH (-1.82 vs -0.88 mmHg, p < 0.001). Intraclass correlation coefficients for variability of clinical BST-data were 0.99 (interobserver) and 0.98 (intraobserver) respectively.

CONCLUSION

BST echocardiography provides accurate estimation of IVPD in early diastole. IVPD was significantly lower in children with UVH compared to controls suggesting lower diastolic suction which can impact overall filling dynamics.

Summary Concerning 16 Years of Research Activities in the Department of Pediatrics at Juntendo University

I described mainly about my research activities in the 16 years and 8 months since I became professor of pediatrics at Juntendo University. Since the fulfillment of research activities has a great influence on clinical activities, and sufficient research cannot be conducted without enhanced educational activities, I have tried to maintain a good balance between clinical practice, research, and education. Research activities in our department often depend on the research abilities of graduate students, but the leadership skills of the professors and associate and assistant professors who supervise the research are also important. First, I talked about the main research of the 12 research groups in our department. In addition, my specialty is pediatric gastroenterology and nutrition, and it is no exaggeration to say that Juntendo Pediatrics is one of the leaders in the field of pediatric gastroenterology and nutrition. I also provided a detailed explanation of research on pediatric inflammatory bowel disease (IBD), which is currently the most important research topic in our department. I hope that this environment will continue to foster the research mindset of young people in a natural way.

Isovolumic relaxation intraventricular pressure difference predicts elevated left ventricular end-diastolic pressure in patients with coronary artery disease

Current guideline for evaluating diastolic function requires multiple parameters to identify patients with elevated left ventricular end-diastolic pressure (LVEDP). However, the intermediate result still exists and may cause LVEDP undetermined. Previous studies have shown intraventricular pressure difference (IVPDs) are required for normal LV filling, but the relationship between IVPDs and LVEDP is unknown. In this study, we analyzed the relationship between IVPDs and LVEDP in 54 patients with coronary artery disease (CAD). LVEDP was prospectively measured at the time of coronary intervention and LVEDP > 15 mmHg was considered as elevated LV filling pressure. Simultaneous echocardiographic data was collected prior to the intervention. The relative intraventricular pressure was calculated using the vector flow mapping method. The IVPD was defined as the pressure difference from the apex to the base of LV. From 54 patients presenting with CAD, elevated LVEDP occurred in 30(55.6%). To analyze the changing trend of IVPD with LVEDP, CAD patients were further divided into group I with normal LVEDP (12.7 ± 3.1 mmHg) and group II with elevated LVEDP (26.0 ± 7.2 mmHg). In early diastole, both isovolumic relaxation period and rapid filling period showed decreased IVPD in CAD patients, but only the reduction in isovolumic relaxation period (IVPD-IVR) was statistical different between patients with elevated LVEDP and normal LVEDP (1.03 ± 0.42 mmHg vs. 2.25 ± 1.21 mmHg, p < 0.01). IVPD-IVR had the best correlation with LVEDP (r=-0.499, p < 0.01) among IVPDs. Lower IVPD-IVR was associated with higher risk of elevated LVEDP. Evaluating IVPD-IVR might improve the diagnostic algorithm for predicting elevated LVEDP.

Sensitive detection of hemodynamic changes after fetoscopic laser photocoagulation by assessing intraventricular pressure difference in fetuses with twin-to-twin transfusion syndrome

OBJECTIVES

To assess the hemodynamics of twin-to-twin transfusion syndrome (TTTS), we measured the intraventricular pressure difference (IVPD), a sensitive marker of myocardial diastolic function, using fetal echocardiography.

METHODS

We included 28 monochorionic diamniotic (MD) twins diagnosed with TTTS who underwent fetoscopic laser photocoagulation (FLP) between 2018 and 2022. Color M-mode Doppler images of both cardiac ventricles were obtained before and after FLP. According to this evaluation, the IVPDs were divided into three groups; those with total, basal, and mid-apical IVPD.

RESULTS

Of the 28 twins, 21 were available for analysis (including eight, eight, three, and two cases in stages Quintero Ⅰ, Ⅱ, Ⅲd, and Ⅲr, respectively). Comparing the pre and postFLP results, significant increases in total and mid-apical IVPD in the left ventricle (LV) of recipient twins were noted (total and mid-apical IVPD: p=0.026 and 0.013, respectively). In the LV of the donor twins, all IVPDs were significantly increased after FLP (total, basal, and mid-apical IVPD: p=0.003, 0.001, and 0.022, respectively). In addition, comparisons between the donor and recipient groups did not show significant differences in either ventricle before FLP.

CONCLUSIONS

IVPD detected subtle hemodynamics changes, such as volume overload and diastolic dysfunction in TTTS before and after FLP. Therefore, IVPD may be a useful marker for monitoring myocardial diastolic function in TTTS.

Assessment of anthracycline-induced cardiotoxicity in childhood cancer survivors during long-term follow-up using strain analysis and intraventricular pressure gradient measurements

BACKGROUND

Cardiac dysfunction due to cardiotoxicity from anthracycline chemotherapy is a leading cause of morbidity and mortality in childhood cancer survivors (CCS), and the cumulative incidence of cardiac events has continued to increase. This study identifies an adequate indicator of cardiac dysfunction during long-term follow-up.

PROCEDURE

In total, 116 patients (median age: 15.5 [range: 4.7-40.2] years) with childhood cancer who were treated with anthracycline were divided into three age groups for analysis (C1: 4-12 years of age, C2: 13-18 years of age, C3: 19-40 years of age), and 116 control patients of similar ages were divided into three corresponding groups (N1, N2, and N3). Layer-specific strains were assessed for longitudinal strain (LS) and circumferential strain (CS). The total and segmental intraventricular pressure gradients (IVPG) were also calculated based on Doppler imaging of the mitral inflow using Euler's equation.

RESULTS

Conventional echocardiographic parameters were not significantly different between the patients and controls. All layers of the LS and inner and middle layers of the basal and papillary CS in all ages and all IVPGs in C2 and C3 decreased compared to those of corresponding age groups. Interestingly, basal CS and basal IVPG in CCS showed moderate correlation and both tended to rapidly decrease with aging. Furthermore, basal IVPG and anthracycline dose showed significant correlations.

CONCLUSIONS

Basal CS and total and basal IVPGs may be particularly useful indicators of cardiotoxicity in long-term follow-up.

Non-Invasive Assessment of the Intraventricular Pressure Using Novel Color M-Mode Echocardiography in Animal Studies: Current Status and Future Perspectives in Veterinary Medicine

The assessment of diastolic function has received great interest in order to comprehend its crucial role in the pathophysiology of heart failure and for the early identification of cardiac events. Silent changes in the intraventricular flow (IVF) dynamics occur before the deterioration of the cardiac wall, although they cannot be detected using conventional echocardiography. Collective information on left ventricular (LV) pressures throughout the cardiac cycle has great value when dealing with patients with altered hemodynamics. Accurate pressure measurement inside the ventricle can be obtained by invasive methods to determine the LV diastolic pressures, which reflect the myocardial relaxation and compliance. However, catheterization is only feasible in the laboratory setting and is not suitable for clinical use due to its disadvantages. In contrast, echocardiography is simple, safe, and accessible. Color M-mode echocardiography (CMME) is an advanced cardiac evaluation technique that can measure the intraventricular pressure differences (IVPDs) and intraventricular pressure gradients (IVPGs) based on the Doppler shift of the IVF. Recently, the assessment of IVPD and IVPG has gained growing interest in the cardiovascular literature in both animal and human studies as a non-invasive method for the early diagnosis of cardiac dysfunctions, especially diastolic ones. The usability of IVPD and IVPG has been reported in various surgically induced heart failure or pharmacologically altered cardiac functions in rats, dogs, cats, and goats. This report aims to give an overview of the current studies of CMME-derived IVPD and IVPG in animal studies and its feasibility for clinical application in veterinary practice and to provide the prospects of the technique's ability to improve our understanding.

Prevalence of Diastolic Dysfunction in Adult Survivors of Childhood Cancer: A Report From SJLIFE Cohort

Background

The prevalence of diastolic dysfunction has not been systematically evaluated in a large population of survivors of childhood cancer using established guidelines and standards.

Objectives

This study sought to assess the prevalence and progression of diastolic dysfunction in adult survivors of childhood cancer exposed to cardiotoxic therapy.

Methods

Comprehensive, longitudinal echocardiographic examinations of adult survivors of childhood cancer ≥18 years of age and ≥10 years from diagnosis in SJLIFE (St. Jude Lifetime Cohort Study) were performed. Diastolic dysfunction was defined based on 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines.

Results

Among 3,342 survivors, the median (25th-75th percentiles [quartile (Q)1-Q3]) age at diagnosis was 8.1 years (Q1-Q3: 3.6-13.7 years), 30.1 years (Q1-Q3: 24.4-37.0 years) at the baseline echocardiography evaluation (Echo 1), and 36.6 years (Q1-Q3: 30.8-43.6 years) at the last follow-up echocardiography evaluation (1,435 survivors) (Echo 2). The proportion of diastolic dysfunction was 15.2% (95% CI: 14.0%-16.4%) at Echo 1 and 15.7% (95% CI: 13.9%-17.7%) at Echo 2, largely attributable to concurrent systolic dysfunction. Less than 5% of survivors with preserved ejection fraction had diastolic dysfunction (2.2% at Echo 1, 3.7% at Echo 2). Using global longitudinal strain assessment in adult survivors with preserved ejection fraction (defined with a cutpoint worse than -15.9%), the proportion of diastolic dysfunction increased to 9.2% at baseline and 9.0% at follow-up.

Conclusions

The prevalence of isolated diastolic dysfunction is low among adults who received cardiotoxic therapies for childhood cancer. The inclusion of left ventricular global longitudinal strain significantly increased the identification of diastolic dysfunction.

Normative change with gestation in fetal intraventricular pressure difference with color M-mode Doppler echocardiography

AIM

The intraventricular pressure difference (IVPD) is the pressure difference in early diastole from the base to the apex of the ventricle. It is a useful marker for evaluating diastolic function because of its role as a suction force. This study investigated the changes in total and segmental IVPDs in normal fetuses throughout gestation to obtain normative data equations.

METHODS

One hundred thirty-seven healthy pregnant women at 12-40 weeks of gestation were prospectively enrolled to evaluate IVPD. The color M mode was performed, and the image was evaluated using our own code to calculate the IVPD. Segmental IVPD was divided into mid to apex and base. Pearson's correlation coefficient was used to evaluate this relationship.

RESULTS

There was a significant, positive relationship between IVPD and gestational age in both ventricles (right ventricle [RV]: r = 0.800, left ventricle [LV]: r = 0.818). As for segmental IVPD, basal and mid-apical IVPD also increased with gestation in both ventricles (RV: basal, r = 0.627; mid-apical, r = 0.705; LV: basal r = 0.758; mid-apical, r = 0.756). IVPG, which was calculated as IVPD/ventricular length, also showed a weak, positive relationship with gestation in both ventricles (RV r = 0.351, p < 0.001; LV r = 0.373, p < 0.001).

CONCLUSION

The total and segmental IVPDs significantly increased linearly through time.

Heart Failure with Preserved Ejection Fraction in Children

Diastolic dysfunction (DD) refers to abnormalities in the mechanical function of the left ventricle (LV) during diastole. Severe LVDD can cause symptoms and the signs of heart failure (HF) in the setting of normal or near normal LV systolic function and is referred to as diastolic HF or HF with preserved ejection fraction (HFpEF). Pediatric cardiologists have long speculated HFpEF in children with congenital heart disease and cardiomyopathy. However, understanding the risk factors, clinical course, and validated biomarkers predictive of the outcome of HFpEF in children is challenging due to heterogeneous etiologies and overlapping pathophysiological mechanisms. The natural history of HFpEF varies depending upon the patient's age, sex, race, geographic location, nutritional status, biochemical risk factors, underlying heart disease, and genetic-environmental interaction, among other factors. Pediatric onset HFpEF is often not the same disease as in adults. Advances in the noninvasive evaluation of the LV diastolic function by strain, and strain rate analysis with speckle-tracking echocardiography, tissue Doppler imaging, and cardiac magnetic resonance imaging have increased our understanding of the HFpEF in children. This review addresses HFpEF in children and identifies knowledge gaps in the underlying etiologies, pathogenesis, diagnosis, and management, especially compared to adults with HFpEF.

Assessment of Early Diastolic Intraventricular Pressure Difference in Children by Blood Speckle-Tracking Echocardiography

BACKGROUND

The lack of reliable echocardiographic techniques to assess diastolic function in children is a major clinical limitation. Our aim was to develop and validate the intraventricular pressure difference (IVPD) calculation using blood speckle-tracking (BST) and investigate the method's potential role in the assessment of diastolic function in children.

METHODS

Blood speckle-tracking allows two-dimensional angle-independent blood flow velocity estimation. Blood speckle-tracking images of left ventricular (LV) inflow from the apical 4-chamber view in 138 controls, 10 patients with dilated cardiomyopathies (DCMs), and 21 patients with hypertrophic cardiomyopathies (HCMs) <18 years of age were analyzed to study LV IVPD during early diastole. Reproducibility of the IVPD analysis was assessed, IVPD estimates from BST and color M mode were compared, and the validity of the BST-based IVPD calculations was tested in a computer flow model.

RESULTS

Mean IVPD was significantly higher in controls (-2.28 ± 0.62 mm Hg) compared with in DCM (-1.21 ± 0.39 mm Hg, P < .001) and HCM (-1.57 ± 0.47 mm Hg, P < .001) patients. Feasibility was 88.3% in controls, 80% in DCM patients, and 90.4% in HCM patients. The peak relative negative pressure occurred earlier at the apex than at the base and preceded the peak E-wave LV filling velocity, indicating that it represents diastolic suction. Intraclass correlation coefficients for intra- and interobserver variability were 0.908 and 0.702, respectively. There was a nonsignificant mean difference of 0.15 mm Hg between IVPD from BST and color M mode. Estimation from two-dimensional velocities revealed a difference in peak IVPD of 0.12 mm Hg (6.6%) when simulated in a three-dimensional fluid mechanics model.

CONCLUSIONS

Intraventricular pressure difference calculation from BST is highly feasible and provides information on diastolic suction and early filling in children with heart disease. Intraventricular pressure difference was significantly reduced in children with DCM and HCM compared with controls, indicating reduced early diastolic suction in these patient groups.

Intraventricular pressure gradient: A novel tool to assess the post-infarction chronic congestive heart failure

Congestive heart failure (CHF), the leading cause of death, is deemed a grave sequel of myocardial infarction (MI). The employment of left ventricular end-diastolic pressure (LVEDP), as a primary indication of CHF, becomes restricted owing to the potential impairment of heart function and caused injury to the aortic valve during its measurement. Echocardiography is the standard technique to detect cardiac dysfunction. However, it exhibits a low capacity to predict the progression of CHF post chronic MI. Being extremely sensitive, noninvasive, and preload-independent, intraventricular pressure gradient (IVPG) was lately introduced to evaluate cardiac function, specifically during cardiomyopathy. Yet, the utility of its use to assess the CHF progression after chronic MI was not investigated. Herein, in the current research, we aimed to study the efficacy of a novel echocardiographic-derived index as IVPG in the assessment of cardiac function in a chronic MI rat model with CHF. Fifty healthy male rats were involved, and MI was surgically induced in 35 of them. Six months post-surgery, all animals were examined using transthoracic conventional and color M-mode echocardiography (CMME) for IVPG. Animals were euthanized the following day after hemodynamics recording. Gross pathological and histological evaluations were performed. J-tree cluster analysis was conducted relying on ten echocardiographic parameters suggestive of CHF. Animals were merged into two main clusters: CHF+ (MI/HF + group, n = 22) and CHF– (n = 28) that was joined from Sham (n = 15), and MI/HF– (n = 13) groups. MI/HF+ group showed the most severe echocardiographic, hemodynamic, anatomic, and histologic alterations. There was no significant change in the total IVPG among various groups. However, the basal IVPG was significantly increased in MI/HF+ group compared to the other groups. The remaining IVPG measures were considerably increased in the MI/HF+ group than in the Sham one. The segmental IVPG measures were significantly correlated with the anatomical, histological, echocardiographic, and hemodynamic findings except for the heart rate. Moreover, they were significant predictors of CHF following a long-standing MI. Conclusively, IVPG obtained from CMME is a substantially promising noninvasive tool with a high ability to detect and predict the progression of CHF following chronic MI compared to conventional echocardiography.

Color M-Mode Echocardiography for Non-Invasive Assessment of the Intraventricular Pressure in Dogs Before and After Ductus Arteriosus Occlusion: A Retrospective Study

Background

Novel non-invasive evaluation of the intraventricular pressure differences and gradients (IVPD and IVPG) by color M-mode echocardiography (CMME) is a promising method in diastolic function evaluation. Patent ductus arteriosus (PDA) is a congenital heart defect which is associated with increased preload. The present work provides a clinical trial for the assessment of IVPD and IVPG changes in dogs before and after surgical occlusion of PDA.

Materials and Methods

A total of 12 client-owned dogs were enrolled in this study. PDA was confirmed using echocardiography, and all dogs underwent PDA occlusion. Conventional echocardiography and CMME were conducted on each patient on the operation day (Pre-PDA) and 48 h after its occlusion (Post-PDA). The total IVPD and total IVPG, as well as segmental intraventricular pressure (basal, mid-to-apical, mid, and apical) were measured from Euler's equation using specific software (MATLAB). Data were analyzed for variability and for the difference between pre- and post-PDA. The effect of PDA occlusion on the measured variables was calculated using biserial ranked correlation (rc).

Results

There was a significant reduction in end-diastolic volume, fraction shortening, stroke volume, and mitral inflow velocities (early and late) after PDA closure. CMME was feasible in all dogs, and the CMME indices showed moderate variability, except for the apical segment of IVPD and IVPG. After PDA closure, in comparison with the pre-PDA occlusion, there was a significant reduction in total IVPD (2.285 ± 0.374 vs. 1.748 ± 0.436 mmHg; P = 0.014), basal IVPD (1.177 ± 0.538 vs. 0.696 ± 0.144 mmHg; P = 0.012), total IVPG (1.141 ± 0.246 vs. 0.933 ± 0.208 mmHg; P = 0.032), and basal IVPG (0.578 ± 0.199 vs. 0.377 ± 0.113 mmHg; P = 0.001); meanwhile, mid, mid-to-apical, and apical segments of both IVPD and IVPG showed non-significant difference. The magnitude of PDA occlusion on the measured variables was clinically relevant and associated with a large effect size on total and basal IVPD and IVPG (rc > 0.6).

Conclusion

The current clinical study revealed matched response of IVPD and IVPG to the reduced preload rather than left ventricular relaxation. This result is an initial step in the clinical utility of CMME-derived IVPD and IVPG measurements in the diastolic function evaluation in dogs with PDA that warrants further clinical studies.

Myocardial Deformation Imaging by Speckle Tracking Echocardiography for Assessment of Cardiotoxicity in Children During and After Chemotherapy: A Systematic Review and Meta-analysis

BACKGROUND

Childhood cancer patients and childhood cancer survivors (CCS) are at risk of developing chemotherapy-induced cardiomyopathy. Myocardial deformation imaging has shown potential in the early detection of subclinical myocardial damage with implications on therapeutic interventions and improvement of outcomes. We aimed to perform a systemic review and meta-analysis of literature on the assessment of left (LV) and right ventricular (RV) myocardial deformation by speckle tracking echocardiography (STE) at rest and during stress in childhood cancer patients during and in survivors after chemotherapy.

METHODS

A systematic review was performed through searching MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, and Scopus. Search hedges were created to cover the concepts of childhood cancer, chemotherapy, radiotherapy, anthracycline, cardiotoxicity, speckle tracking, myocardial strain, and myocardial deformation. Two independent investigators reviewed the eligibility of the articles for inclusion. Weighted mean difference in ventricular strain between pre-and post-chemotherapy treatment and that between long-term CCS and healthy subjects were estimated by random-effect models with 95% confidence intervals. Heterogeneity and publication bias were assessed by I2 statistics and Egger test, respectively.

RESULTS

Of the total of 8703 records initially identified, 42 studies with a total of 430 childhood cancer patients were included. Of these 42 studies that showed heterogeneities, 9 assessed early myocardial injury during chemotherapy, 30 assessed late myocardial injury after chemotherapy with no publication bias, and 3 studied myocardial mechanics during stress. The main findings were 1) impairment of LV systolic deformation in childhood cancer patients during the initial treatment phase and among long-term CCS, while data on changes in RV deformation are limited and inconclusive, 2) the predictive value of early reduction of myocardial strain imaging in forecasting subsequent development of cardiotoxicity is unknown as it has not been studied, 3) limited data suggest possibility of impaired LV contractile mechanics during stress in CCS, and 4) cumulative anthracycline dose and chest-directed radiotherapy are consistently identified as factors associated with impaired myocardial deformation.results CONCLUSIONS: Myocardial strain imaging by STE unveils early evidence of myocardial injury in childhood cancer patients and long-term CCS. To support its adoption for clinical use, more data are required for the better understating of myocardial deformation parameters in the risk stratification of childhood cancer patients and prediction of development of cardiomyopathy among CCS.

Effect of Loading Changes on the Intraventricular Pressure Measured by Color M-Mode Echocardiography in Rats

Evaluation of diastolic function is a pivotal challenge due to limitations of the conventional echocardiography, especially when the heart rate is rapid as in rats. Currently, by using color M-mode echocardiography (CMME), intraventricular pressure difference (IVPD) and intraventricular pressure gradient (IVPG) in early diastole can be generated and are available as echocardiographic indices. These indices are expected to be useful for the early diagnosis of heart failure (HF), especially diastolic dysfunction. There have not been any studies demonstrating changes in IVPD and IVPG in response to changes in loading conditions in rats. Therefore, the present study aims to evaluate CMME-derived IVPD and IVPG changes in rats under various loading conditions. Twenty rats were included, divided into two groups for two different experiments, and underwent jugular vein catheterization under inhalational anesthetics. Conventional echocardiography, CMME, and 2D speckle tracking echocardiography were measured at the baseline (BL), after intravenous infusion of milrinone (MIL, n = 10), and after the infusion of hydroxyethyl starch (HES, n = 10). Left ventricular IVPD and IVPG were calculated from color M-mode images and categorized into total, basal, mid-to-apical, mid, and apical parts, and the percentage of the corresponding part was calculated. In comparison to the BL, the ejection fraction, mid-to-apical IVPG, mid IVPG, and apical IVPD were significantly increased after MIL administration (p < 0.05); meanwhile, the end-diastolic volume, E-wave velocity, total IVPD, and basal IVPD were significantly increased with the administration of HES (p < 0.05). The increase in mid-to-apical IVPD, mid IVPD, and apical IVPD indicated increased relaxation. A significant increase in basal IVPD reflected volume overloading by HES. CMME-derived IVPD and IVPG are useful tools for the evaluation of various loading conditions in rats. The approach used in this study provides a model for continuous data acquisition in chronic cardiac disease models without drug testing.

Left ventricular diastolic pressure gradient and outcome in advanced chronic kidney disease patients with preserved ejection fraction

Assessment of left ventricular (LV) diastolic dysfunction is important in patients with chronic kidney disease (CKD). The early diastolic peak intraventricular pressure gradient (IVPG) has a vital role in diastolic function. Relative pressure imaging (RPI) is a new echocardiographic method to quantify IVPG. The purpose of this study was to analyze RPI-derived IVPG in advanced CKD patients with preserved LV ejection fraction. The study population consisted of 51 advanced CKD patients and 39 healthy controls. Patients were stratified by the evidence of heart failure with preserved ejection fraction (HFpEF) into HFpEF group (32 patients) and non-HFpEF group (19 patients). RPI analysis was used to determine the early diastolic LV relative pressure and pressure distribution. The total IVPG and segmental IVPGs corresponding to basal, mid, and apical part of the LV were calculated. Total IVPG, along with apical and mid IVPGs were all significantly reduced in HFpEF Group compared with non-HFpEF Group and controls (all P < 0.05). But no significant difference of total or segmental IVPGs was found between non-HFpEF Group and the controls. Additionally, apical IVPG < 0.02 mmHg/cm (Hazard ratio 9.82, 95 % confidence interval 2.01-48.01, P = 0.005) was the independent risk factor for the composite outcome (mortality and cardiovascular hospitalization) during a median follow-up of 24 months. Advanced CKD patients with HFpEF exhibited decreased apical and mid IVPG of the LV, and the severity of apical IVPG reduction correlated with poor outcome.

The Utility of Intraventricular Pressure Gradient for Early Detection of Chemotherapy-Induced Subclinical Cardiac Dysfunction in Dogs

Early detection of doxorubicin (DXR)-induced cardiomyopathy (DXR-ICM) is crucial to improve cancer patient outcomes and survival. In recent years, the intraventricular pressure gradient (IVPG) has been a breakthrough as a sensitive index to assess cardiac function. This study aimed to evaluate the usefulness of IVPG for the early detection of chemotherapy-related cardiac dysfunction. For this purpose, six dogs underwent conventional, speckle tracking, and color M-mode echocardiography concomitantly with pressure-and-volume analysis by conductance catheter. The cardiac function measurements were assessed before DXR administration (baseline, Pre), at the end of treatment protocol (Post), and at 1.5 years follow-up (Post2). The result showed a significant reduction in the left ventricular end-systolic pressure-volume (Emax: 4.4 ± 0.7, 6.1 ± 1.6 vs. 8.4 ± 0.8 mmHg/mL), total-IVPG (0.59 ± 0.12, 0.62 ± 0.15 vs. 0.86 ± 0.12 mmHg), and mid-IVPG (0.28 ± 0.12, 0.31 ± 0.11 vs. 0.48 ± 0.08 mmHg), respectively in Post2 and Post compared with the baseline (p < 0.05). Mid-to-apical IVPG was also reduced in Post2 compared with the baseline (0.29 ± 0.13 vs. 0.51 ± 0.11). Meanwhile, the fraction shortening, ejection fraction, and longitudinal strain revealed no change between groups. Total and mid-IVPG were significantly correlated with Emax (R = 0.49; p < 0.05, both) but only mid-IVPG was a predictor for Emax (R2 = 0.238, p = 0.040). In conclusion, this study revealed that impairment of contractility was the initial changes observed with DXR-ICM in dogs and only IVPG could noninvasively detect subclinical alterations in cardiac function. Color M-mode echocardiography-derived IVPG could be a potential marker for the early detection of doxorubicin cardiomyopathy.

Assessment of left-ventricular diastolic function in pediatric intensive-care patients: a review of parameters and indications compared with those for adults

BACKGROUND

The incidence of diastolic heart failure has increased over time. The evaluation of left-ventricular diastolic function is complex, ongoing, and remains poorly performed in pediatric intensive-care patients. This study aimed to review the literature and to provide an update on the evaluation of left-ventricular diastolic function in adults and children in intensive care.

DATA SOURCES

We searched data from PubMed/Medline. Thirty-two studies were included. Four pragmatic questions were identified: (1) What is the physiopathology of diastolic dysfunction? (2) Which tools are required to evaluate diastolic function? (3) What are the echocardiographic criteria needed to evaluate diastolic function? (4) When should diastolic function be evaluated in pediatric intensive care?

RESULTS

Early diastole allows characterization of relaxation, whereas compliance assessments and filling pressures are evaluated during late diastole. The evolution of diastolic function differs between adults and children. Unlike in adults, decreased compliance occurs at the same time as delayed relaxation in children. Diastolic function can be evaluated by Doppler echocardiography. The echocardiographic criteria for ventricular relaxation include the E wave, E/A wave ratio, and isovolumic relaxation time. Ventricular compliance can be assessed by the E/e' wave ratio, atrial volume, and Ap wave duration during pulmonary vein flow. In adult intensive-care patients, the E/e' ratio can be used as an index of tolerance for volume expansion in septic patients and to adjust the inotropic support.

CONCLUSION

Clinical studies would allow some of these parameters to be validated for use in children in intensive care.

Key factors of diastolic dysfunction and abnormal left ventricular relaxation in diabetic rats

PURPOSE

To study the diastolic functions using color Doppler M-mode (CDMM) for noninvasive analysis of the intraventricular pressure difference (IVPD) in diabetic rats.

METHODS

Two equal groups of rats were included: control and streptozotocin-induced DM (n = 15). The cardiac functions were examined monthly using conventional echocardiography and CDMM with a specific MATLAB software. Echocardiography was performed under 2% isoflurane mask inhalation. Five months thereafter, all rats were killed for macroscopic and microscopic examinations of the cardiac fibrosis.

RESULTS

DM rats showed higher systolic blood pressure and diastolic dysfunction, i.e., decreases in several parameters such as E, E/A, TDIs, and IVPDs, compared to the controls. Moreover, obvious cardiac fibrosis was seen in perivascular and interstitial tissues, but there were no notable differences in terms of gross lesions.

CONCLUSIONS

Because of the noninvasive nature of CDMM, IVPD and other conventional echocardiographic parameters can be used as reliable indicators generally for evaluating cardiac function and particularly the change in intraventricular pressure.