Ventricular Volume Measurements Research Articles

Evaluating Linear Heuristics for Ventricular Volume in Healthy Adults Using a Fully Automated Algorithm: Implications for Defining the Normal.

Linear metrics for ventricular volume play a large role in the rapid, approximate evaluation of ventricular volume. In this article, we automatically extract linear measures of ventricular volume to explore their correlation with lateral ventricular volume (LVV) in the healthy adult population and comprehensively define normal values. We automatically extract Evans' ratio (ER), Frontal-Occipital Horn Ratio (FOHR), and anteroposterior lateral ventricle index (ALVI) from an open MRI data set of healthy adults (https://brain-development.org/ixi-dataset/). Indices have been correlated with corresponding LVVs and lateral ventricular volumes divided by supratentorial brain volumes. Spearman rank correlation was used to compare strength of correlation. ER shows correlation with lateral ventricle volume based on sex (r = 0.58; men, r = 0.65; women P < .001), including when controlling for supratentorial volume (r = 0.57; men, r = 0.63). ER did not profoundly correlate with age (r = 0.29, men; r = 0.35, women; P < .001) and seemed normally distributed around 0.25. ALVI showed strong correlation with LVV with only slight gender differences (r = 0.83, men; r = 0.84, women) and LVV to supratentorial cortical volume ratio (r = 0.9, men; r = 0.86, women). FOHR was also normally distributed around a value of 0.37 and showed moderate correlation with LVV (r = 0.68, men; r = 0.73, women) and LVV to supratentorial cortical volume ratio (r = 0.69, men; r = 0.74, women). ALVI is a newer index with strong correlation with LVV and has strong potential for clinical use. Both FOHR and ER show moderate correlation with LVV. Reference values for linear estimates of ventricular volume may help clinicians better identify patients with pathological ventriculomegaly.

Concordance of left ventricular volumes and function measurements between two human readers, a fully automated AI algorithm, and the 3D heart model.

Echocardiography is essential in cardiovascular medicine for screening, diagnosis, and monitoring. Artificial intelligence (AI) has the potential to improve echocardiography by reducing variability and analysis time. While 3D echocardiography is becoming more accurate, 2D imaging still dominates clinical care. We aimed to evaluate agreement in measures of left ventricular (LV) volumes and function between human readers, a fully automated AI 2D algorithm, and the 3D Heart Model. A retrospective analysis was conducted on 109 patients who underwent 2D and 3D transthoracic echocardiography. LV end-diastolic and end-systolic volumes (LVEDV, LVESV) and ejection fraction (LVEF) were measured by two operators, a commercially available AI algorithm (US2ai), and the 3D Heart Model. Global longitudinal strain (GLS) was measured by the integrated semi-automated software and the AI algorithm. Outcomes included measures of agreement [bias, limit of agreement and Pearson's correlation (R)]. For LV volume measurements, the AI algorithm was strongly correlated with the average of the human operators (r = 0.89 for LVEDV and r = 0.92 for LVESV), which was higher than between the operators (r = 0.74 and r = 0.84, respectively, p < 0.01). The same trend was seen for measures of reliability with respect to LVEDV, but not LVESV. AI demonstrated comparable performance to human operators in measuring LVEF, while the 3D Heart Model had a weaker correlation and reliability compared with human operators and AI measurements. The correlation between human operators and AI for GLS was only moderate. This study demonstrates AI-based echocardiography as a promising tool for accurately assessing LV volumes and LVEF in clinical practice. AI-based measures demonstrated a significantly lower inter-operator variability, thereby improving the consistency and reliability of these assessments. Moreover, AI may prove particularly effective for conducting retrospective bulk analyses, offering a valuable tool for comprehensive evaluations of past data.

Measurement of left ventricular volume with admittance incorporated onto percutaneous ventricular assist device.

Percutaneous ventricular assist devices (pVADs) incorporated with admittance electrodes have been validated in animal studies for accurate instantaneous volumetric measurements. Since miniaturization of the pVAD profile is a priority to reduce vascular complications in patients, our study aimed to validate admittance measurements using three electrodes instead of the standard four. Complex admittance was measured between an electrode pair and a pVAD metallic blood-intake tip, both with finite element analysis and on the benchtop. The catheter and electrode arrays were first simulated inside prolate ellipsoid models of the left ventricle (LV) demonstrating current flow throughout all parts of the LV as well as minimal influence of off-center catheter placement in the recorded signal. Admittance measurements were validated in 3D-printed models of healthy and dilated hearts (100-400mL end-diastolic volumes). Minimal interference between a pVAD motor and the current signal of our admittance system was demonstrated. A modified Wei's equation focused on three electrodes was developed to be compatible with reduced profile pVADs occurring clinically, incorporated with admittance electrodes and wires. The modified equation was compared against Wei's original equation showing improved accuracy of calculated volumes. Reducing electrode footprint can simplify the incorporation of Admittance technology on any pVAD, allowing for instantaneous recognition of native heart recovery and assistance with pVAD weaning.

Empagliflozin to prevent progressive adverse remodelling after myocardial infarction (EMPRESS-MI): rationale and design.

Patients with a reduced left ventricular ejection fraction (LVEF) following an acute myocardial infarction (MI) are at risk of progressive adverse cardiac remodelling that can lead to the development of heart failure and death. The early addition of a sodium-glucose cotransporter 2 (SGLT2) inhibitor to standard treatment may delay or prevent progressive adverse remodelling in these patients. EMpagliflozin to PREvent worSening of left ventricular volumes and Systolic function after Myocardial Infarction (EMPRESS-MI) is a randomized, double-blind, placebo-controlled, multi-centre trial designed to assess the effect of empagliflozin on cardiac remodelling evaluated using cardiovascular magnetic resonance (CMR) in 100 patients with left ventricular systolic dysfunction following MI. Eligible patients were those ≥12h and ≤14days following acute MI, with an LVEF <45% by CMR. Patients were randomized to empagliflozin 10mg once a day or matching placebo. The primary outcome will be change in left ventricular end-systolic volume indexed to body surface area over 24weeks from randomization. Secondary endpoints include measures of left ventricular and atrial volumes, left ventricular mass, LVEF, and circulating cardiac biomarkers. EMPRESS-MI will assess the effect of the SGLT2 inhibitor empagliflozin on cardiac remodelling in patients with left ventricular systolic dysfunction after an acute MI.

Macrophage to Myofibroblast Transition Promotes Hypertension-Induced Cardiac Diastolic Dysfunction

Cardiac diastolic dysfunction is a pathological continuum of hypertension eventually leading to heart failure—which is responsible for ~13% of all deaths in the United States. A hallmark of this disease is cardiac fibrotic remodeling, in which excessive extracellular matrix components are deposited into the myocardium. Recent studies have shown the novel ability of macrophages to differentiate into a fibrotic myofibroblast-like phenotype—termed macrophage to myofibroblast transition (MMT). This phenomenon has been implicated in renal fibrosis but, has not been investigated in the heart during hypertension or diastolic dysfunction. Therefore, we hypothesize that MMT plays a causal role in cardiac fibrotic remodeling in hypertension, promoting diastolic dysfunction. As such, we seek to investigate the prevalence of myofibroblast-transitioned macrophages in the heart, as well as determine the gravity of MMT-mediated fibrotic cardiac remodeling. To understand the pathological progression of hypertension to diastolic dysfunction, we utilized the classic DOCA + NaCl model of hypertension in C57BL/6 mice. This investigation is multi-pronged, in that, we seek to gauge diastolic function in vivo, as well as investigate the microenvironment of the heart in primary in vitro experiments. To achieve this, we employ echocardiography and direct left ventricular pressure and volume measurements to determine the progression of hypertension to diastolic dysfunction in the adult mouse heart. For primary in vitro analyses, mouse hearts were isolated and digested, and leukocytes were isolated by Percoll gradient. Cells were stained with α-SMA (myofibroblast) and CD68 (monocyte/macrophage). Finally, the deposition of fibrotic collagen was assessed by both Masson’s trichrome and picrosirius red tissue stains. Mice were subjected to DOCA + salt to induce hypertension. Ten days after this treatment, the left ventricular pressure change as a function of time was measured in the left ventricle. This analysis revealed degraded heart function, realized by a significant decrease in -dp/dt as soon as ten days following the onset of hypertension. Following, another cohort of hypertensive WT mouse hearts was isolated for staining. The results of these assays revealed increased cardiac fibrosis in the hearts of hypertensive mice—likely contributing to the deficit in cardiac function. Finally, in addition to this, flow cytometric analyses of isolated cardiac leukocytes revealed that hypertensive mice had a significant increase in the α-SMA+/CD68+ population of cells in the hypertensive mouse heart, implicating MMT in the rapid pathological progression of hypertension to diastolic dysfunction. These results characterize the presence of MMT cells in the hypertensive mouse heart. Furthermore, the increase of myofibroblast transition is accompanied by decreased cardiac diastolic function and enhanced fibrotic remodeling in the heart—alluding to the role of MMT in the pathological progression of hypertension to diastolic dysfunction. Future efforts into this phenomenon involve the real-time progression of hypertension to diastolic dysfunction via echocardiography, as well as a final, definitive measurement of diastolic function by PV loop. Finally, we will employ an angiotensin II model of hypertension to ensure that this phenomenon is encapsulated in other forms of hypertension, rather than just the DOCA + Salt model. We thank our sources of funding:NIG R01-HL146713, AHA 23TPA1076467. 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.

Correlating Evans Index, Callosal Angle, and Lateral Ventricle Volume With Gait Response Outcomes in Idiopathic Normal Pressure Hydrocephalus Diagnosis.

Radiological imaging is pivotal in diagnosing idiopathic normal pressure hydrocephalus (iNPH), given the similarity of its symptoms to other neurodegenerative diseases. We aimed to correlate the Evans index (EI), callosal angle (CA), and the volume of the lateral ventricles measured before cerebrospinal fluid removal with the resultant outcomes in gait response. In our retrospective study, we identified 42 patients with a diagnosis of iNPH. These patients underwent gait analysis, imaging, and lumbar puncture. Radiological assessments included measurements of CA EI and lateral ventricular volume. Clinically, we assessed the following 4 gait parameters: cadence, gait speed, stride length, and timed up and go. Change in the 4 gait parameters was calculated, normalized, and compiled into a composite score, following which the group was divided into 'responders' and 'nonresponders' based on z score of 0.5. Our dependent variable was clinical improvement in gait, and our independent variables included lateral ventricular volume, EI, and CA. We performed a Wilcoxon rank-sum test to compare significant responder status using CA, EI, and lateral ventricle volume. A receiver operating characteristic analysis was employed to determine which volume measurement exhibited the strongest correlation with responder status. Determining the significant variables, a chi-square analysis was subsequently conducted.A significance threshold was set at P < 0.05. All our statistical evaluations were conducted in the Spyder environment, which is compatible with Python 3.10. There was a significant difference for responder status in EI and lateral ventricle volume. Evan index showing a statistic of 2.202 (P value = 0.02) and lateral ventricle volume demonstrating a statistic of 2.086 (P value = 0.03). Subsequent exploration using receiver operating characteristic analysis, with area under the curve of 0.71, identified 105.40 cm3 as the most robustly correlated volume threshold with responder status. The lateral ventricular volume demonstrates a stronger correlation with gait improvement compared to the CA or EI. These observations indicate that evaluating the lateral ventricle volume before lumbar puncture could serve as a predictor for gait response after lumbar puncture in individuals with normal pressure hydrocephalus.

The IAAM LTBP4 Haplotype is Protective Against Dystrophin-Deficient Cardiomyopathy.

Dilated cardiomyopathy (DCM) is a major complication of, and leading cause of mortality in Duchenne muscular dystrophy (DMD). Its severity, age at onset, and rate of progression display wide variability, whose molecular bases have been scarcely elucidated. Potential DCM-modifying factors include glucocorticoid (GC) and cardiological treatments, DMD mutation type and location, and variants in other genes. We retrospectively collected 3138 echocardiographic measurements of left ventricular ejection fraction (EF), shortening fraction (SF), and end-diastolic volume (EDV) from 819 DMD participants, 541 from an Italian multicentric cohort and 278 from the Cooperative International Neuromuscular Group Duchenne Natural History Study (CINRG-DNHS). Using generalized estimating equation (GEE) models, we estimated the yearly rate of decrease of EF (-0.80%) and SF (-0.41%), while EDV increase was not significantly associated with age. Utilizing a multivariate generalized estimating equation (GEE) model we observed that mutations preserving the expression of the C-terminal Dp71 isoform of dystrophin were correlated with decreased EDV (-11.01 mL/m2, p = 0.03) while for dp116 were correlated with decreased EF (-4.14%, p = <0.001). The rs10880 genotype in the LTBP4 gene, previously shown to prolong ambulation, was also associated with increased EF and decreased EDV (+3.29%, p = 0.002, and -10.62 mL/m2, p = 0.008) with a recessive model. We quantitatively describe the progression of systolic dysfunction progression in DMD, confirm the effect of distal dystrophin isoform expression on the dystrophin-deficient heart, and identify a strong effect of LTBP4 genotype of DCM in DMD.

Evolution of Severe Closed Head Injury: Assessing Ventricular Volume and Behavioral Measures at 30 and 90 Days Post-Injury

Background: Assessing functional outcomes in Severe Closed Head Injury (SCHI) is complex due to brain parenchymal changes. This study examines the Ventricles to Intracranial Volume Ratio (VBR) as a metric for these changes and its correlation with behavioral scales. Methods: Thirty-one SCHI patients were included. VBR was derived from CT scans at 3, 30, and 90 days post-injury and compared with Levels of Cognitive Functioning (LCF), Disability Rating Scale (DRS), and Early Rehabilitation Barthel Index (ERBI) assessments at 30 and 90 days. Results: Ten patients were excluded post-decompressive craniectomy or ventriculoperitoneal shunt. Findings indicated a VBR decrease at 3 days, suggesting acute phase compression, followed by an increase from 30 to 90 days, indicative of post-acute brain atrophy. VBR correlated positively with the Marshall score in the initial 72 h, positioning it as an early indicator of subsequent brain atrophy. Nevertheless, in contrast to the Marshall score, VBR had stronger associations with DRS and ERBI at 90 days. Conclusions: VBR, alongside behavioral assessments, presents a robust framework for evaluating SCHI progression. It supports early functional outcome correlations informing therapeutic approaches. VBR’s reliability underscores its utility in neurorehabilitation for ongoing SCHI assessment and aiding clinical decisions.

S-100β level is closely associated with myocardial work in patients with acute ischemic stroke

BackgroundThe more severe the acute stroke is, the more serious myocardial damage is. This study aimed to determine the relationship between myocardial work and S100β, a quantitative biomarker of active cerebral lesions, in patients with acute ischemic stroke (AIS). MethodsA total of 63 patients with AIS were examined by myocardial work echocardiography, 4D echocardiography with the measurement of left ventricular (LV) myocardial work, volume and function within 24-48 h of symptom onset, respectively. Their plasma S100β was measured from a peripheral blood sample within 2-6 h of symptom onset. ResultsPatients with elevated S-100β level had significantly increased ratios of peak early diastolic transmitral filling velocity to peak early diastolic lateral mitral annulus tissue velocity(E/e’) and global longitudinal strain (GLS), and significantly reduced global work index(GWI) and global constructive work (GCW) compared with those with normal S-100β level (p < 0.05). S-100β positively correlated with E/e’(r = 0.878, p < 0.0001) and GLS (r = 0.511, p = 0.002) but negatively correlated with GWI(r = −0.409, p = 0.034) and GCW(r = −0.353, p = 0.041). S-100β showed an excellent ability to differentiate if a reduced GWI [cut-off value, 120.79 pg/mL; area under receiver operating characteristic curve (AUC), 1.000; sensitivity, 100%; specificity, 100%], GCW (cut-off value, 120.79 pg/mL;AUC,1.000; sensitivity,100%; specificity, 100%) and an increased E/e’ (cut-off value, 91.1 pg/mL;AUC,0.913; sensitivity,80%; specificity, 100%) or not, but poor ability to differentiate if an increased GLS(cut-off value, 91.1 pg/mL; AUC,0.576; sensitivity,63.64%; specificity, 83.33%) or not. ConclusionS-100β level is closely associated with LV function. It is highly competent in determining an impaired myocardial work in patients with AIS.

Comparison of cardiac magnetic resonance imaging, functional and haemodynamic variables in pulmonary arterial hypertension: insights from REPAIR.

Measures that can detect large treatment effects are important for monitoring therapeutic effectiveness. The 2022 European Society of Cardiology/European Respiratory Society guidelines highlight the importance of imaging in monitoring disease status and treatment response in pulmonary arterial hypertension (PAH). Are the standardised treatment effect sizes (STES) of cardiac magnetic resonance imaging (cMRI) comparable with functional and haemodynamic variables? REPAIR (ClinicalTrials.gov: NCT02310672) was a prospective, multicentre, single-arm, open-label, 52-week phase 4 study evaluating the effect of macitentan 10 mg, with or without a phosphodiesterase 5 inhibitor (PDE5i), on right ventricular (RV) remodelling, cardiac function and cardiopulmonary haemodynamics. Both cMRI and functional assessments were performed at screening and at weeks 26 and 52; haemodynamic measurements were conducted at screening and week 26. In this post hoc analysis, STES were estimated using the parametric Cohen's d and non-parametric Cliff's delta tests. At week 26, large STES (Cohen's d) were observed for 10 of the 20 cMRI variables assessed, including the prognostic measures of RV and left ventricular stroke volume and RV ejection fraction and the haemodynamic trial end-point, pulmonary vascular resistance; medium STES were observed for 6-min walk distance (6MWD). The STES were consistent in treatment-naïve patients and those escalating therapy and maintained at week 52. Similar results were obtained using the non-parametric Cliff's delta method. The treatment effect of macitentan, alone or in combination with a PDE5i, was comparable for several cMRI and haemodynamic variables with prognostic value in PAH, and greater than that of 6MWD in patients with PAH, highlighting the emerging relevance of cMRI in PAH.

Automatic measurements of left ventricular volumes and ejection fraction by artificial intelligence: clinical validation in real time and large databases.

Echocardiography is a cornerstone in cardiac imaging, and left ventricular (LV) ejection fraction (EF) is a key parameter for patient management. Recent advances in artificial intelligence (AI) have enabled fully automatic measurements of LV volumes and EF both during scanning and in stored recordings. The aim of this study was to evaluate the impact of implementing AI measurements on acquisition and processing time and test-retest reproducibility compared with standard clinical workflow, as well as to study the agreement with reference in large internal and external databases. Fully automatic measurements of LV volumes and EF by a novel AI software were compared with manual measurements in the following clinical scenarios: (i) in real time use during scanning of 50 consecutive patients, (ii) in 40 subjects with repeated echocardiographic examinations and manual measurements by 4 readers, and (iii) in large internal and external research databases of 1881 and 849 subjects, respectively. Real-time AI measurements significantly reduced the total acquisition and processing time by 77% (median 5.3 min, P < 0.001) compared with standard clinical workflow. Test-retest reproducibility of AI measurements was superior in inter-observer scenarios and non-inferior in intra-observer scenarios. AI measurements showed good agreement with reference measurements both in real time and in large research databases. The software reduced the time taken to perform and volumetrically analyse routine echocardiograms without a decrease in accuracy compared with experts.

Evaluation of a Fully Automated Method for Ventricular Volume Segmentation Before and After Shunt Surgery in Idiopathic Normal Pressure Hydrocephalus

Determination of the ventricle size in idiopathic normal pressure hydrocephalus (iNPH) is essential for diagnosis and follow-up of shunt results. Fully automated segmentation methods are anticipated to optimize the accuracy and time efficiency of ventricular volume measurements. We evaluated the accuracy of preoperative and postoperative ventricular volume measurements in iNPH by a magnetic resonance imaging (MRI)-based licensed software for fully automated quantitative assessment. Forty-eight patients diagnosed with iNPH were retrospectively analyzed. All patients received a ventriculoperitoneal shunt and had symptom grading and routine MRI preoperatively and 3-6 months postoperatively. Ventricular volumes, generated by fully automated T1-weighted imaging volume sequence segmentation, were compared with semiautomatic measurements and routine radiologic reports. The relation of postoperative ventricular size change to clinical response was evaluated. Fully automated segmentation was achieved in 95% of the MRIs, but showed various rates of 8 minor segmentation errors. The correlation between both segmentation methods was very strong (r >0.9) and the agreement very good using Bland-Altman analyses. The ventricular volumes differed significantly between semiautomated and fully automated segmentations and between preoperative and postoperative MRI. The fully automated method systematically overestimated the ventricles by a median 15 mL preoperatively and 14 mL postoperatively; hence, the magnitudes of volume changes were equivalent. Routine radiologic reports of ventricular size changes were inaccurate in 51% and lacked association with treatment response. Objectively measured ventricular volume changes correlated moderately with postoperative clinical improvement. A fully automated volumetric method permits reliable evaluation of preoperative ventriculomegaly and postoperative ventricular volume change in idiopathic normal pressure hydrocephalus.

Assessment of Left Ventricular Function Using Two- And Three-Dimensional Speckle Tracking Echocardiography among Healthy Egyptian Pediatric-Aged Children

Abstract Background Accurate measurements of left ventricular volumes and function are important in the management of patients with various cardiac abnormalities. Speckle tracking echocardiography has shown to be accurate in detecting subclinical myocardial dysfunction when most of the conventional echocardiograph parameters were normal or reported inconsistent results Aim of the Study To establish normal values for the LV systolic function among healthy Egyptian pediatric population using 2D and 3D speckle tracking Echocardiography. Patients and Methods the study included 200 subjects who attended cardiology department Ain Shams University for elective echocardiology below 6 years of age with unremarkable history and no chronic illness affecting LV function with normal 2D echocardiography. Results The study involved 200 subjects with age ranged from 0.1 to 5.9 years and its mean was 3.8±1.5 years. 104 were males representing 52% of subjects of the study while females were 96 representing 48%. Their weight ranged from 3.5 to 28 Kg and its mean was 17.14±4.9 Kg. Their height ranged from 0.11 to 1.24 M and its mean was 1.012±0.178 M. Body surface area ranged from 0.22 to 1.1 Kg/m2 and its mean was 0.695±0.151 Kg/m2. Regarding the 2D speckle tracking parameters: longitudinal strain ranged from -18.6% to -24.6% with its mean was -21.314±1.57%. Circumferential strain was from -16.7% to 23.4% and its mean -19.02±1.23%. And radial strain ranged from 36.4% to 52.6% with mean 42.392±2.794%. Regarding the 3D speckle tracking data: longitudinal strain ranged from -17% to -30% with its mean was -20.73±2.039%. Circumferential strain was from -11% to -21% with its mean -13.259±4.670%. And radial strain ranged from 41% to 61% with its mean 47.511±4.82%.

A Computational Model of Ventricular Dimensions and Hemodynamics in Growing Infants.

Previous computer models have successfully predicted cardiac growth and remodeling in adults with pathologies. However, applying these models to infants is complicated by the fact that they also undergo normal, somatic cardiac growth and remodeling. Therefore, we designed a computational model to predict ventricular dimensions and hemodynamics in healthy, growing infants by modifying an adult canine left ventricular growth model. The heart chambers were modeled as time-varying elastances coupled to a circuit model of the circulation. Circulation parameters were allometrically scaled and adjusted for maturation to simulate birth through 3 yrs of age. Ventricular growth was driven by perturbations in myocyte strain. The model successfully matched clinical measurements of pressures, ventricular and atrial volumes, and ventricular thicknesses within two standard deviations of multiple infant studies. To test the model, we input 10th and 90th percentile infant weights. Predicted volumes and thicknesses decreased and increased within normal ranges and pressures were unchanged. When we simulated coarctation of the aorta, systemic blood pressure, left ventricular thickness, and left ventricular volume all increased, following trends in clinical data. Our model enables a greater understanding of somatic and pathological growth in infants with congenital heart defects. Its flexibility and computational efficiency when compared to models employing more complex geometries allow for rapid analysis of pathological mechanisms affecting cardiac growth and hemodynamics.

Ultrasonographic Estimation of Ventricular Volume in Infants Born Preterm with Posthemorrhagic Ventricular Dilatation: A Nested Substudy of the Randomized Controlled Early Versus Late Ventricular Intervention Study (ELVIS) Trial

To study the potential role of ventricular volume (VV) estimation in the management of posthemorrhagic ventricular dilatation related to the need for ventriculoperitoneal (VP)-shunt insertion and 2-year neurodevelopmental outcome in infants born preterm. We included 59 patients from the Early vs Late Ventricular Intervention Study from 4 participating centers. VV was manually segmented in 209 3-dimensional ultrasound scans and estimated from 2-dimensional ultrasound linear measurements in a total of 1226 ultrasounds. We studied the association of both linear measurements and VV to the need for VP shunt and 2-year neurodevelopmental outcome in the overall cohort and in the 29 infants who needed insertion of a reservoir. We used general estimating equations to account for repeated measures per individual. Maximum pre-reservoir VV (β coefficient=0.185, P=.0001) and gestational age at birth (β =-0.338; P=.0001) were related to the need for VP shunt. The estimated optimal single VV measurement cut point of 17cm3 correctly classified 79.31% with an area under the curve of 0.76 (CI 95% 0.74-0.79). Maximum VV (β=0.027; P=.012) together with VP shunt insertion (β =3.773; P=.007) and gestational age (β =-0.273; P=.0001) were related to cognitive outcome at 2years. Maximum ventricular index and anterior horn width before reservoir insertion were independently associated with the need of VP shunt and the proposed threshold groups in the Early vs Late Ventricular Intervention Study trial were associated with long-term outcome. Pre-reservoir VV measurements were associated with the need for VP-shunt insertion and 2-year cognitive outcome among infants born preterm with posthemorrhagic ventricular dilatation. ISRCTN43171322.

Automatic measurements of left ventricular volumes and ejection fraction by artificial intelligence reduces time-consumption and inter-observer variability

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Norwegian University of Science and Technology. Background Left ventricular (LV) volumes and ejection fraction (EF) are the most used and studied parameters in echocardiography, but they are hampered with the tedious nature and limited reproducibility of manual measurements. We developed an artificial intelligence (AI) decision-support software that automatically calculates LV volumes and EF by identifying the view, timing, and endocardial border from echo images. Purpose Our aim was to investigate the impact of using the AI decision-support software for automatic measurements of LV volumes and EF compared to standard care in real-time and large databases. Methods We compared biplane three-cycle averaged AI measurements of LV volumes and EF to manual references in multiple samples: 1) Real-time AI-support during scanning of 50 consecutive patients compared to standard care (test-retest) by two of three experts, 2) comparison of test-retest variability in inter- and intra-observer scenarios in 40 subjects with test-retest datasets by separate observers and measurements by AI and four experienced observers, 3) an internal database of 1881 subjects with manual references by Simpson’s method, and 4) an external population of 849 subjects with manual references by semi-automatic tracking-based software. The influence on time consumption was tested in Sample 1. The influence on test-retest variability was tested in Sample 1 and 2, while the other samples were used to test the agreement with echocardiographic references. Results Used in real-time the AI measurements reduced total time-consumption by median (95% CI) 5.3 (4.8–6.5) minutes per patient (p &amp;lt;0.001). The test-retest variability for AI-measurements were superior to inter-observer scenarios (p &amp;lt;0.05) and non-inferior to intra-observer scenarios (p &amp;lt;0.025, one-sided, delta=46% increased variance). The agreement with echocardiographic references was good (Figure). The biases (AI minus reference) ranged −11.6 to 6.5 mL for end-diastolic LV volume and −5.5 to 0.3 %-points for EF. Conclusion Fully automatic AI measurements of LV volumes and EF reduced time-consumption with 5 minutes, reduced test-retest variability compared to inter-observer analyses, and showed acceptable agreement with manual measurements in a wide range of scenarios. Thus, implementation of real-time fully automatic measurements of LV volumes and EF during scanning may improve the everyday workflow and quality in the everyday clinic.

A comparison between the apical and subcostal view for three-dimensional echocardiographic assessment of right ventricular volumes in pediatric patients.

Accurate measurement of ventricular volumes is an important clinical imaging goal. Three-dimensional echocardiography (3DEcho) is used increasingly as it is more available and less costly than cardiac magnetic resonance (CMR). For the right ventricle (RV), the current practice is to acquire 3DEcho volumes from the apical view. However, in some patients the RV may be better seen from the subcostal view. Therefore, this study compared RV volume measurements from the apical vs. the subcostal view, using CMR as a reference standard. Patients <18 years old undergoing a clinical CMR examination were prospectively enrolled. 3DEcho was performed on the day of the CMR. 3DEcho images were acquired with Philips Epic 7 ultrasound system from apical and subcostal views. Offline analysis was performed with TomTec 4DRV Function for 3DEcho images and cvi42 for CMR ones. RV end-diastolic volume and end-systolic volume were collected. Agreement between 3DEcho and CMR was assessed with Bland-Altman analysis and the intraclass correlation coefficient (ICC). Percentage (%) error was calculated using CMR as the reference standard. Forty-seven patients were included in the analysis (age range 10 months to 16 years). The ICC was moderate to excellent for all volume comparisons to CMR (subcostal vs. CMR: end-diastolic volume 0.93, end-systolic volume 0.81; apical vs. CMR: end-diastolic volume 0.94, end-systolic volume 0.74).The 3DEcho mean % error vs. CMR for end-systolic volume was 25% for subcostal and 31% for apical; for end-diastolic volume it was 15% for subcostal and 16% for apical. The % error was not significantly different between apical vs. subcostal views for end-systolic and end-diastolic volume measurements. For apical and subcostal views, 3DEcho-derived ventricular volumes agree well with CMR. Neither echo view has a consistently smaller error when compared to CMR volumes. Accordingly, the subcostal view can be used as an alternative to the apical view when acquiring 3DEcho volumes in pediatric patients, particularly when the image quality from this window is superior.

Beat-by-beat volume calibration refines pressure-volume derived indices of left ventricular function in the rat

Objective: Cardiac pressure-volume studies have advanced much of our understanding of mammalian cardiovascular physiology. Using admittance or conductance technology, the advantage of this technology over other methods to assess cardiovascular function is the ability to derive beat-by-beat pressure-volume loops and generate estimations of myocardial work (stroke work), as well as load-independent systolic (i.e., contractility) and diastolic (i.e., compliance) function from a caval occlusion. While these catheters are capable of extremely accurate recordings of cardiac pressure, volume measurement relies on a series of calibration steps that are oft-performed in isolation or at discrete timepoints. We propose a novel method that enables the refinement of ventricular volume measurement by enabling a beat-by-beat calibration of stroke volume (SV) at baseline and, most importantly, during caval occlusion where both the shape and characteristics of the ventricle are dynamically changing. Hypothesis: We hypothesised that beat-by-beat calibration of SV has a significant effect on PV-catheter derived indices of left ventricle (LV) function. Methodology: Data were collected from 10 rodents that were intubated, ventilated, and urethane anesthetized. We placed an admittance pressure-volume catheter (1.6F Scisense, Transonic Systems, Inc.) into the LV via an apical approach following thoracotomy, a perivascular flow probe (Transonic Systems, Inc.) was placed around the ascending aorta, a blood pressure catheter in the iliac artery, femoral venous lines for fluid/drug infusions, and an arterial line for blood gas analysis. We then assessed baseline and load-independent systolic function using the admittance catheter with and without beat-by-beat volume corrections obtained by integration of the perivascular flow data. Results: Firstly, we confirmed that the standard metrics of load-independent systolic function were increased in response to dobutamine (β1 agonist) and reduced in response to esmolol (β1 blocker). We then found that beat-by-beat volume correction from the perivascular flow probe increased baseline measures of SV and stroke work (SW). Comparing indices of load-independent systolic function calculated from corrected vs. uncorrected values of SV and SW, we found that beat-by-beat volume correction resulted in no significant change in d P/dt max - V ed (P=0.339) but a significant increase in PRSW (from 116±18 to 129±20 mmHg, P=0.020). Conclusions: Standard approaches to PV studies are able to accurately discern changes in contractile state. However, beat-by-beat calibration of the volume signal improves the absolute determination of volume indices and therefore influences derived measures of contractility. This research was funded by an NSERC Alliance grant to CRW and Mitacs Accelerate Postdoctoral Fellowship to OHW. This is the full abstract presented at the American Physiology Summit 2023 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.

Using computed tomography fusion imaging as learning data for sonographer training in identification of left ventricular endocardial boundaries

BackgroundWe hypothesized that if computed tomography (CT) images were used as learning data, we could overcome volume underestimation by echocardiography, improving the accuracy of left ventricular (LV) volume measurements. MethodsWe utilized a fusion imaging modality consisting of echocardiography with superimposed CT images for 37 consecutive patients to identify the endocardial boundary. We compared LV volumes obtained with and without CT learning trace-lines (TLs). Furthermore, 3D echocardiography was used to compare LV volumes obtained with and without CT learning for endocardial identification. The mean difference between the echocardiography and CT-derived LV volumes and the coefficient of variation were compared pre- and post-learning. Bland–Altman analysis was used to assess the differences in LV volume (mL) obtained from the 2D pre-learning TL and 3D post-learning TL. ResultsThe post-learning TL was located closer to the epicardium than the pre-learning TL. This trend was particularly pronounced in the lateral and the anterior wall. The post-learning TL was along the inner side of the high echoic layer in the basal-lateral wall in the four-chamber view. CT fusion imaging determined that the difference in LV volume between 2D echocardiography and CT was small (−25.6 ± 14.4 mL before learning, −6.9 ± 11.5 mL after learning) and that CT learning improved the coefficient of variation (10.9 % before learning, 7.8 % after learning). Significant improvements were observed during 3D echocardiography; the difference in LV volume between 3D echocardiography and CT was slight (−20.5 ± 15.1 mL before learning, 3.8 ± 15.7 mL after learning), and the coefficient of variation improved (11.5 % before learning, 9.3 % after learning). ConclusionsDifferences between the LV volumes obtained using CT and echocardiography either disappeared or were reduced after CT fusion imaging. Fusion imaging is useful in training regimens for accurate LV volume quantification using echocardiography and may contribute to quality control.

Prediction of Male Coronary Artery Bypass Grafting Outcomes Using Body Surface Area Weighted Left Ventricular End-diastolic Diameter: Multicenter Retrospective Cohort Study

The presence of a high left ventricular end-diastolic diameter (LVEDD) has been linked to a less favorable outcome in patients undergoing coronary artery bypass grafting (CABG) procedures. However, by taking into consideration the reference of left ventricular size and volume measurements relative to the patient's body surface area (BSA), it has been suggested that the accuracy of the predicting outcomes may be improved. We propose that BSA weighted LVEDD (bLVEDD) is a more accurate predictor of outcomes in patients undergoing CABG compared to simply using LVEDD alone. This study was a comprehensive retrospective cohort study that was conducted across multiple medical centers. The inclusion criteria for this study were patients who were admitted for treatment between October 2016 and May 2021. Only elective surgery patients were included in the study, while those undergoing emergency surgery were not considered. All participants in the study received standard care, and their clinical data were collected through the institutional registry in accordance with the guidelines set forth by the Society of Thoracic Surgeons National Adult Cardiac Database. bLVEDD was defined as LVEDD divided by BSA. The primary outcome was in-hospital all-cause mortality (30 days), and the secondary outcomes were postoperative severe adverse events, including use of extracorporeal membrane oxygenation, multiorgan failure, use of intra-aortic balloon pump, postoperative stroke, and postoperative myocardial infarction. In total, 9474 patients from 5 centers under the Chinese Cardiac Surgery Registry were eligible for analysis. We found that a high LVEDD was a negative factor for male patients' mortality (odds ratio 1.44, P<.001) and secondary outcomes. For female patients, LVEDD was associated with secondary outcomes but did not reach statistical differences for morality. bLVEDD showed a strong association with postsurgery mortality (odds ratio 2.70, P<.001), and secondary outcomes changed in parallel with bLVEDD in male patients. However, bLVEDD did not reach statistical differences when fitting either mortality or severer outcomes in female patients. In male patients, the categorical bLVEDD showed high power to predict mortality (area under the curve [AUC] 0.71, P<.001) while BSA (AUC 0.62) and LVEDD (AUC 0.64) both contributed to the risk of mortality but were not as significant as bLVEDD (P<.001). bLVEDD is an important predictor for male mortality in CABG, removing the bias of BSA and showing a strong capability to accurately predict mortality outcomes. ClinicalTrials.gov NCT02400125; https://clinicaltrials.gov/ct2/show/NCT02400125.