Short-axis View Research Articles

Reliability of post-contrast deep learning-based highly accelerated cardiac cine MRI for the assessment of ventricular function.

The total examination time can be reduced if high-quality two-dimensional (2D) cine images can be collected post-contrast to minimize non-scanning time prior to late gadolinium-enhanced imaging. This study aimed to assess the equivalency of the pre-and post-contrast performance of 2D deep learning-based highly accelerated cardiac cine (DL cine) imaging by evaluating the image quality and the quantification of biventricular volumes and function in the clinical setting. Thirty patients (20 men, mean age 53.7 ± 17.8 years) underwent cardiac magnetic resonance on a 1.5 T scanner for clinical indications, and pre- and post-contrast DL cine images were acquired with a short-axis view. Image-quality was scored according to three main criteria: the blood-to-myocardial contrast, endocardial edge delineation, and presence of motion artifacts throughout the cardiac cycle. Biventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and left ventricular mass (LVM) were analyzed and compared between the pre- and post-contrast DL cine images. The actual median time of 2D DL cine acquisition was 38.4 ± 9.1 s. There were no significant differences in the image quality scores between pre- and post-contrast DL cine images (p > 0.05). In the volume and functional analysis, there was no significant difference in terms of biventricular EDV, ESV, SV, EF, and LVM (p > 0.05). The performance of 2D DL cine is equivalent before and after contrast injection for the assessment of image quality and ventricular function in the clinical setting.

Mean pulmonary artery pressure prediction with explainable multi-view cardiac MR cine series deep learning model

BackgroundPulmonary hypertension (PH) is a heterogeneous condition and regardless of aetiology impacts negatively on survival. Diagnosis of PH is based on hemodynamic parameters measured invasively at right heart catheterization (RHC), however, a non-invasive alternative would be clinically valuable. Our aim was to estimate RHC parameters non-invasively from cardiac MR data using deep learning models and to identify key contributing imaging features. MethodsWe constructed an explainable convolutional neural network (CNN) taking cardiac MR cine series from 4 different views as input to predict mean pulmonary artery pressure (mPAP). The model was trained and evaluated on 1646 examinations. The model’s attention weight and predictive performance associated with each frame, view, or phase was used to judge its importance. Additionally, the importance of each cardiac chamber was inferred by perturbing part of the input pixels. ResultsThe model achieved a Pearson Correlation Coefficient (PCC) of 0.80 and R2 of 0.64 in predicting mPAP, and identified the right ventricle (RV) region on short-axis (SAX) view to be especially informative. ConclusionsHemodynamic parameters can be estimated non-invasively with a CNN, using MR cine series from 4 views, revealing key contributing features at the same time.

Transthoracic cardiac ultrasonic shear wave elastography for detecting myocardial stiffness in healthy and hypertrophic cardiomyopathy individuals

Objective: To explore the feasibility of transthoracic cardiac shear wave elastography (SWE) for non-invasive quantitative measurement of myocardial stiffness in healthy volunteers (HV) and hypertrophic cardiomyopathy (HCM) patients, and analyze the relationship between myocardial shear wave velocity (SWV) and left ventricular diastolic function. Methods: A total of 16 HV who underwent health check-ups and 5 HCM patients who visited the Cardiology Outpatient Clinic at Fujian Medical University Affiliated Union Hospital from September 2022 to October 2023 were prospectively recruited. The SWE technique was used to measure SWV of the basal segment of the interventricular septum, including left ventricular long-axis myocardial shear wave velocity (LA-SWV) and short-axis myocardial shear wave velocity (SA-SWV). The intraclass correlation coefficient (ICC) was employed to evaluate the intra-observer and inter-observer consistency of SWV measurements. Spearman's correlation analysis was performed to evaluate the correlation between baseline characteristics, echocardiography parameters and SWV. Quantitative data were expressed as median (interquartile range) [M (Q1, Q3)]. Results: The HV group had the age of 34.5 (24.0, 51.0) years, including 8 males (50%); the HCM group had the age of 34.0 (27.0, 46.0) years, including 3 males (60%). The intra-observer and inter-observer ICC (95%CI) for LA-SWV measurements were 0.806 (0.592-0.907) and 0.785 (0.471-0.949), respectively, indicating high consistency; the intra-observer and inter-observer ICC (95%CI) for SA-SWV measurements were 0.746 (0.359-0.862) and 0.602 (0.245-0.834), indicating moderate consistency. LA-SWV [1.74 (1.65, 1.77) vs 1.25 (1.22, 1.33) m/s, P<0.001] and SA-SWV [1.98 (1.96, 2.15) vs 1.52(1.46, 1.55) m/s, P<0.001] were significantly higher in HCM group than those in HV group. There was no significant correlation between SWV and gender, age or body mass index (all P>0.05). In the left ventricular long-axis view, interventricular septal end-diastolic thickness (IVSDT) (r=0.749, P<0.001), early diastolic mitral valve flow velocity/early diastolic mitral annular peak motion velocity (E/e') (r=0.669, P<0.001), and left ventricular mass index (LVMI) (r=0.679, P<0.001) were positively correlated with LA-SWV, while e' (r=-0.545, P<0.001) and late diastolic mitral annular peak motion velocity (r=-0.489, P=0.021) were negatively correlated with LA-SWV. In the left ventricular short-axis view, IVSDT (r=0.784, P<0.001), E/e' (r=0.657, P<0.001), and LVMI (r=0.660, P<0.001) were positively correlated with SA-SWV, while e' was negatively correlated with SA-SWV (r=-0.658, P<0.001). Conclusions: The use of SWE technique to measure myocardial SWV can be applied to assess the stiffness differences between normal myocardium and HCM myocardium. Additionally, SWV is correlated with left ventricular diastolic function indices and can effectively evaluate the diastolic dysfunction of the left ventricle caused by HCM.

Left ventricular myocardial work predicts clinical course in patients with heart failure with mildly reduced ejection fraction

Abstract Heart failure with mildly reduced ejection fraction (HFmrEF) often represents a movable patients subset that changes its HF category by increasing or reducing EF. Course prediction is challenging due to insufficient evidence to date. We studied multiple newly established parameters in order to find predictors of clinical course of HFmrEF. Methods 135 patients (61 women) 62±5 years with HFmrEF NYHA II-III on GDMT were enrolled. Longitudinal (GLS), circumferential (GCS) and radial strain (GRS), peak LV twist (LVTR) were measured by speckle tracking from apical and short axis views. Left ventricular (LV) global myocardial work (GW) index (GWI) was obtained from pressure-strain loops derived from LV GLS and supine systemic blood pressure measured right before the image acquisition. Then constructive GW (GCW) as the sum of positive work due to myocardial shortening during systole and negative work due to lengthening during isovolumic relaxation, wasted GW (GWW) as energy loss by myocardial lengthening in systole and shortening in isovolumic relaxation and GW efficiency (GWE) as the percentage ratio of constructive work to the sum of constructive work and wasted work were obtained by dedicated software. All parameters were analyzed offline by one experienced specialist. Patients were followed up for 1 year. Results 38 (28%) patients improved EF to the value ≥50%, 31 (23%) reduced EF to ≤40%. Patients with improved EF had significantly higher absolute values of GLS (17.3±2.2 vs 15.8±3.1%, p&amp;lt;0.03), GCS (18.9±2.6 vs 16.1±1.9%, p&amp;lt;0.02), GRS (42.5±7.2% vs 31.3±4.7%, p&amp;lt;0.02), LVT (6.2±2.5° vs 5.3±2.3°, p&amp;lt;0.03), GCW (2253±121 vs 1872±132 mmHg%, p&amp;lt;0.001) and lower GWW (108±7 vs 128±12 mmHg%) compared with patients with later reduced EF. Multivariate analysis showed that lower GCW was associated with EF reduction (HR 0.982, 95% CI 0.969–0.996, p = 0.012). GCW was the powerful predictor of CV events (AUC 0.94) with cut off value of 1495 mmHg% that had 98% sensitivity and 86% specificity. Conclusion LV GCW predicts EF changes in patients with HFmrEF.

Cardiac magnetic resonance T1 imaging for the diagnosis of cardiac amyloidosis among patients with symptomatic heart failure

Abstract Background Cardiac amyloidosis (CA) is a significant cause of heart failure in elderly patients. However, specific signs in cardiac imaging are lacking, hence bone scintigraphy in combination with screening for monoclonal protein, or myocardial biopsy is required for the diagnosis. Cardiac magnetic resonance (CMR) imaging with T1 mapping is a promising diagnostic tool, which may allow to differentiate causes of left ventricular (LV) hypertrophy, particularly CA. Purpose The aim of this study was to test the diagnostic accuracy of T1 mapping for the diagnosis of CA in elderly patients with symptomatic heart failure and red flags for CA. Methods We prospectively enrolled 120 patients aged above 60 years with symptomatic heart failure NYHA II-IV, LV ejection fraction ≥ 40%, increased LV wall thickness of ≥ 12 mm end-diastolic on echocardiography, and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≥ 1,000 ng/L, high-sensitivity cardiac troponin T (hs-cTnT) ≥ 14 ng/L). All patients underwent standardized quantitative CMR with a 3.0T scanner. 99mTc-DPD bone scintigraphy, blood screening for monoclonal protein, and, where applicable, cardiac biopsy, were performed as reference methods in all patients. Primary endpoint was diagnostic accuracy of native T1 mapping for the diagnosis of CA. Results 112 patients were included in the final analysis. Median age was 81.0 years (interquartile range 74.0–85.0 years), and 45% were female. CA was diagnosed in 38 patients (34%), of which 32 suffered from a Transthyretin (ATTR) and 6 patients from light chain (AL) amyloidosis. The areas under the receiver operating characteristic curves for native T1 were 0.713, 0.772, 0.836 for global, septal short-axis (SAX), and septal 4-chamber (4Ch) view measurements. The corresponding value of extracellular volume fraction (ECV) was 0.904 (Figure 1). Based on these results, we developed a new diagnostic algorithm for the diagnosis of CA including T1 septal 4Ch and ECV, with a sensitivity and positive predictive value of both 92.9% and a specificity and negative predictive value of 95.8% (Figure 2). Thereby, contrast application can be avoided in 33% of patients. A definite diagnosis could be provided in 81%. Conclusion CMR with T1 imaging provides a high diagnostic accuracy to diagnose CA in patients with symptomatic heart failure at risk for CA. These data may help to identify underlying causes in heart failure which require specific treatment. An earlier diagnosis of CA may improve outcome of these patients.Figure 1Figure 2

Ventricular interaction and clinical outcomes in patients undergoing transcatheter tricuspid valve repair

Abstract Background Excessive volume overload of the right ventricle (RV) due to tricuspid regurgitation (TR) can cause a leftward shift of the interventricular septum and changes left ventricular (LV) geometry, which leads to decreases LV distensibility and results in cardiac output. This unfavorable ventricular interaction might have prognostic impacts of patients undergoing transcatheter tricuspid valve repair (TTVr). Purpose We investigated the association between the ventricular interaction and clinical outcomes in patients undergoing TTVr. Methods We retrospectively assessed 304 patients who underwent TTVr. The ventricular interaction was assessed using LV eccentricity index which was defined as LV antero-posterior dimension / LV septo-lateral dimension at end-diastole in the parasternal short-axis view (Figure 1). Increased ventricular interaction was defined as LV eccentricity index ≥1.2. The primary outcome was a composite of all-cause mortality and heart failure hospitalization within one year after TTVr. Results The mean LV eccentricity index at baseline was 1.23 ± 0.20, and 168 of 304 patients (55.3%) had increased ventricular interaction. Patients with increased ventricular interaction were more likely to have massive or torrential TR, reduced RV function, larger RV areas, and lower cardiac index. Increased ventricular interaction at baseline was associated with an increased risk of the composite outcome (HR 2.14; 95%CI 1.36–3.37; p=0.001; Figure 2A), which was consistent after adjusting for age, male sex, renal function, LV ejection fraction, RV function, and residual TR. Echocardiography at baseline showed that 83 of 168 patients (49.4%) with increased ventricular interaction at baseline had an improvement in the ventricular interaction (i.e., LV eccentricity index ≥1.2 at baseline but &amp;lt;1.2 at discharge), which was associated with a lower risk of the composite outcome than persisted ventricular interaction (i.e., LV eccentricity index ≥1.2 at both baseline and discharge) (Figure 2B), irrespectively of baseline characteristics and residual TR. Smaller RV area and residual TR ≤2+ were related to the improved ventricular interaction. Conclusion Ventricular interaction, defined as LV eccentricity index ≥1.2, is associated with an increased risk of clinical outcomes after TTVr. However, the post-procedural improvement in ventricular interaction after TTVr may be linked to better prognosis.Figure 1Figure 2

Myocardial parametric mapping in patients with suspected acute myocarditis: a prognosis study

Abstract Background T1 mapping and T2 mapping have become essential components of the 2018 Lake Louise criteria and obtained excellent results in diagnosing myocarditis. However, their prognostic value in acute myocarditis has not yet been well recognized or established. Purpose Our study aims to investigate the prognostic value of T1 mapping, T2 mapping, and extracellular volume fraction (ECV) in a large cohort of patients with suspected acute myocarditis. Materials Patients meeting the recommended clinical criteria for suspected acute myocarditis were consecutively enrolled. The primary endpoint is the composite of cardiac death, heart failure hospitalization, heart transplantation, sustained ventricular arrhythmia, and recurrent myocarditis, defined as major adverse cardiovascular events (MACE). All patients underwent CMR at 3.0 T scanner using a standardized, routine imaging protocol, and the three short-axis view slices (basal, mid-ventricular, and apical) were divided into 16 segments according to the American Heart Association 17-segment model (apex excluded). We also averaged the native T1 values, ECV, and T2 values of all 16 segments to get global T1 and ECV fraction values, respectively. Statistically significant parameters from univariate Cox analyses were put into multivariate Cox analysis. Results A total of 235 patients (150 men; 32±13 years) were enrolled in this study. During a mean follow-up of 43.0±3.6 months, MACE occurred in 37 patients (15.7%) and was univariably associated with heart failure presentation, left ventricular ejection fraction, left ventricular end-systolic volume index, left ventricular end-diastolic volume index, native T1 and ECV. Patients with MACE showed higher global native T1, ECV, and T2 values (1348±59 vs 1266±51, p=&amp;lt;0.001; 40.0±8.7 vs 32.8±5.9, p&amp;lt;0.001; 63.4±12.1 vs. 55.5±9.1, p=0.011), and were more likely to have tissue changes in the interventricular septum and anterior wall (Figure 1). In a series of nesting multivariable Cox regression models, the addition of native T1 (per 10-ms increase: HR, 1.128; 95% CI: 1.043, 1.220; p = 0.003; Harrell’s C-index = 0.833) or ECV (per 5% increase: HR, 1.382; 95% CI: 1.060, 1.802; p = 0.017; Harrell’s C-index = 0.847) improved prognostication compared with the model based on clinical variables, left ventricular ejection fraction, and septal late gadolinium enhancement (Harrell’s C-index = 0.762) (Figure 2). T2 in multivariate Cox regression analysis didn’t show predictive value, but his inclusion increased the C-index of the model to 0.814. Conclusions Myocardial parametric mapping not only holds substantial diagnostic value but also plays a critical role in the prognostic assessment and risk prediction of myocarditis. Their utilization in these contexts enhances the accuracy and effectiveness of clinical evaluations and decision-making processes.

U-Net and Its Variants Based Automatic Tracking of Radial Artery in Ultrasonic Short-Axis Views: A Pilot Study.

Background/Objectives: Radial artery tracking (RAT) in the short-axis view is a pivotal step for ultrasound-guided radial artery catheterization (RAC), which is widely employed in various clinical settings. To eliminate disparities and lay the foundations for automated procedures, a pilot study was conducted to explore the feasibility of U-Net and its variants in automatic RAT. Methods: Approved by the institutional ethics committee, patients as potential RAC candidates were enrolled, and the radial arteries were continuously scanned by B-mode ultrasonography. All acquired videos were processed into standardized images, and randomly divided into training, validation, and test sets in an 8:1:1 ratio. Deep learning models, including U-Net and its variants, such as Attention U-Net, UNet++, Res-UNet, TransUNet, and UNeXt, were utilized for automatic RAT. The performance of the deep learning architectures was assessed using loss functions, dice similarity coefficient (DSC), and Jaccard similarity coefficient (JSC). Performance differences were analyzed using the Kruskal-Wallis test. Results: The independent datasets comprised 7233 images extracted from 178 videos of 135 patients (53.3% women; mean age: 41.6 years). Consistent convergence of loss functions between the training and validation sets was achieved for all models except Attention U-Net. Res-UNet emerged as the optimal architecture in terms of DSC and JSC (93.14% and 87.93%), indicating a significant improvement compared to U-Net (91.79% vs. 86.19%, p < 0.05) and Attention U-Net (91.20% vs. 85.02%, p < 0.05). Conclusions: This pilot study validates the feasibility of U-Net and its variants in automatic RAT, highlighting the predominant performance of Res-UNet among the evaluated architectures.

Deep learning super-resolution reconstruction for fast and high-quality cine cardiovascular magnetic resonance.

To compare standard-resolution balanced steady-state free precession (bSSFP) cine images with cine images acquired at low resolution but reconstructed with a deep learning (DL) super-resolution algorithm. Cine cardiovascular magnetic resonance (CMR) datasets (short-axis and 4-chamber views) were prospectively acquired in healthy volunteers and patients at normal (cineNR: 1.89 × 1.96 mm2, reconstructed at 1.04 × 1.04 mm2) and at a low-resolution (2.98 × 3.00 mm2, reconstructed at 1.04 × 1.04 mm2). Low-resolution images were reconstructed using compressed sensing DL denoising and resolution upscaling (cineDL). Left ventricular ejection fraction (LVEF), end-diastolic volume index (LVEDVi), and strain were assessed. Apparent signal-to-noise (aSNR) and contrast-to-noise ratios (aCNR) were calculated. Subjective image quality was assessed on a 5-point Likert scale. Student's paired t-test, Wilcoxon matched-pairs signed-rank-test, and intraclass correlation coefficient (ICC) were used for statistical analysis. Thirty participants were analyzed (37 ± 16 years; 20 healthy volunteers and 10 patients). Short-axis views whole-stack acquisition duration of cineDL was shorter than cineNR (57.5 ± 8.7 vs 98.7 ± 12.4 s; p < 0.0001). No differences were noted for: LVEF (59 ± 7 vs 59 ± 7%; ICC: 0.95 [95% confidence interval: 0.94, 0.99]; p = 0.17), LVEDVi (85.0 ± 13.5 vs 84.4 ± 13.7 mL/m2; ICC: 0.99 [0.98, 0.99]; p = 0.12), longitudinal strain (-19.5 ± 4.3 vs -19.8 ± 3.9%; ICC: 0.94 [0.88, 0.97]; p = 0.52), short-axis aSNR (81 ± 49 vs 69 ± 38; p = 0.32), aCNR (53 ± 31 vs 45 ± 27; p = 0.33), or subjective image quality (5.0 [IQR 4.9, 5.0] vs 5.0 [IQR 4.7, 5.0]; p = 0.99). Deep-learning reconstruction of cine images acquired at a lower spatial resolution led to a decrease in acquisition times of 42% with shorter breath-holds without affecting volumetric results or image quality. Question Cine CMR acquisitions are time-intensive and vulnerable to artifacts. Findings Low-resolution upscaled reconstructions using DL super-resolution decreased acquisition times by 35-42% without a significant difference in volumetric results or subjective image quality. Clinical relevance DL super-resolution reconstructions of bSSFP cine images acquired at a lower spatial resolution reduce acquisition times while preserving diagnostic accuracy, improving the clinical feasibility of cine imaging by decreasing breath hold duration.

Feasibility of fractal dimension analysis for left ventricular trabecular complexity using cardiac computed tomography

AimsTo evaluate the consistency between fractal dimensions (FD) derived from cardiac computed tomography (CT-FD) and cardiac magnetic resonance (MR-FD) in assessing left ventricular trabecular complexity. MethodsThis retrospective study included 170 patients who underwent CCT and CMR scans within two weeks. Five short-axis cine images were selected at end-diastole: one basal, three mid, and one apical slice. Short-axis CCT views were reconstructed and aligned with the cine images. CT-FD and MR-FD values were calculated for each slice, with mean values determined for each patient. Severe left ventricular hypertrophy (LVH) was defined as a maximum wall thickness > 15 mm in end-diastolic cine images. ResultsThe diastolic CT-FD and MR-FD values exhibited high consistency, with values of 1.253 ± 0.091 and 1.250 ± 0.102, respectively (n = 535, ICC = 0.882, 95 % CI: 0.861–0.899, P < 0.001). Similarly, the systolic CT-FD and MR-FD values demonstrated good consistency, with values of 1.268 ± 0.072 and 1.286 ± 0.093, respectively (n = 390, ICC = 0.720, 95 % CI: 0.669–0.765, P < 0.001). For subgroups of systolic NLVH and LVH, the ICCs were 0.773 (n = 305, CI: 0.723–0.814, P < 0.001) and 0.565 (n = 85, 95 % CI: 0.402–0.694, P < 0.001), respectively. The diagnostic efficacy of mean CT-FD aligned with that of mean MR-FD in distinguishing abnormal cardiac conditions from the CMR-negative group. ConclusionsCCT is a feasible method for assessing left ventricular trabecular complexity, with good agreement with CMR, except in cases of severe left ventricular hypertrophy during systole.

Segmentation-Free Estimation of Left Ventricular Ejection Fraction Using 3D CNN Is Reliable and Improves as Multiple Cardiac MRI Cine Orientations Are Combined.

We aimed to study classical, publicly available convolutional neural networks (3D-CNNs) using a combination of several cine-MR orientation planes for the estimation of left ventricular ejection fraction (LVEF) without contour tracing. Cine-MR examinations carried out on 1082 patients from our institution were analysed by comparing the LVEF provided by the CVI42 software (V5.9.3) with the estimation resulting from different 3D-CNN models and various combinations of long- and short-axis orientation planes. The 3D-Resnet18 architecture appeared to be the most favourable, and the results gradually and significantly improved as several long-axis and short-axis planes were combined. Simply pasting multiple orientation views into composite frames increased performance. Optimal results were obtained by pasting two long-axis views and six short-axis views. The best configuration provided an R2 = 0.83, a mean absolute error (MAE) = 4.97, and a root mean square error (RMSE) = 6.29; the area under the ROC curve (AUC) for the classification of LVEF < 40% was 0.99, and for the classification of LVEF > 60%, the AUC was 0.97. Internal validation performed on 149 additional patients after model training provided very similar results (MAE 4.98). External validation carried out on 62 patients from another institution showed an MAE of 6.59. Our results in this area are among the most promising obtained to date using CNNs with cardiac magnetic resonance. (1) The use of traditional 3D-CNNs and a combination of multiple orientation planes is capable of estimating LVEF from cine-MRI data without segmenting ventricular contours, with a reliability similar to that of traditional methods. (2) Performance significantly improves as the number of orientation planes increases, providing a more complete view of the left ventricle.

Formation of the interatrial septum: Insights obtained from cardiac computed tomographic angiography.

We previously described a septal variant termed left atrial septal pouch (LASP). Present in a third of hearts, it results from incomplete fusion of the septum primum (SP) and septum secundum (SS). We assessed the prevalence of LASP using 64-section multidetector computed tomography and further characterized the different variants. Among 864 scans, 770 were of sufficient quality for assessment (428 male, aged 59.2 ± 11.7 years). They were classified on the basis of the degrees of fusion of the SP and SS into a completely fused septum (CFS), patent foramen ovale (PFO), or LASP. The lengths of the SS, SP, and overlapping SP, the maximal length of the foramen ovale (FO) floor, and the atrial dimensions were compared. A PFO was seen in 181 patients (23.5%), a LASP in 242 (31.4%), and a CFS in 339 (44.0%). There were significant differences in the length of the SS (PFO-13.6 ± 4.3 mm, LASP-17.6 ± 4.8 mm, CFS-14.3 ± 7.7 mm, p < 0.001). Hearts with LASPs had a longer overlapping SP than those with PFOs (PFO-6.3 ± 4.5 mm, LASP-13.1 ± 5.2 mm, p < 0.001). The maximal lengths of the FO floor showed differences in short axis (SAX) view (PFO-21.7 ± 4.5 mm, LASP-15.3 ± 4.3 mm, CFS-16.3 ± 4.3 mm, p < 0.001). Hearts with PFO and LASP showed similar SP lengths (27.3 ± 6.6 mm vs. 26.4 ± 6.6 mm, p = 0.10). There was a positive linear correlation between the length of the SS and the overlapping SP (R2 = 0.28, p < 0.001) with a weaker negative correlation between the SS length and maximal length of the FO floor (R2 = 0.02, p < 0.001). The groups showed similar atrial dimensions and volumes. Present in a third of patients, hearts with LASP have longer SS and overlapping SP.

MMP-8 causes leftward shift in end-diastolic pressure-volume relationship and may explain the development of diastolic dysfunction in septic cardiomyopathy.

Septic cardiomyopathy (SCM) with diastolic dysfunction carries a poor prognosis, and the mechanisms underlying the development of diastolic dysfunction remain unclear. Matrix metalloproteinase-8 (MMP-8) is released from neutrophils and degrades collagen I. MMP-8 levels correlate with SCM severity. We scrutinized, for the first time, the direct impact of MMP-8 on cardiac systolic and diastolic functions. Isolated rat hearts were perfused with Krebs-Henseleit solution in a Langendorff setup with computer-controlled filling pressures of both ventricles in an isovolumetric regime. The end-diastolic pressure (EDP) varied periodically between 3 and 20 mmHg. After baseline recordings, MMP-8 (100 µg/mL) was added to the perfusion. Short-axis views of both ventricles were continuously acquired by echocardiography. MMP-8 perfusion resulted in a progressive decline in peak systolic pressures (Psys) in both ventricles, but without significant changes in their end-systolic pressure-area relationships (ESPARs). Counterintuitively, conspicuous leftward shifts of the end-diastolic pressure-area relationships (EDPARs) were observed in both ventricles. The left ventricle (LV) end-diastolic area (EDA) decreased by 32.8 ± 5.7% (P = 0.008) at an EDP of 10.5 ± 0.4 mmHg, when LV Psys dropped by 20%. The decline of Psys was primarily due to the decrease in EDA, and restoring the baseline EDA by increasing EDP recovered 81.33 ± 5.87% of the pressure drop. Collagen I generates tensile (eccentric) stress, and its degradation by MMP-8 causes end-diastolic pressure-volume relationship (EDPVR) leftward shift, resulting in diastolic and systolic dysfunctions. The diastolic dysfunction explains the clinically observed fluid unresponsiveness, whereas the decrease in end-diastolic volume (EDV) diminishes the systolic functions. MMP-8 can explain the development of SCM with diastolic dysfunction.NEW & NOTEWORTHY MMP-8, released from activated neutrophils and macrophages, is markedly elevated in sepsis, correlating with sepsis severity and mortality. MMP-8 targets collagen I of the cardiac ECM and induces diastolic dysfunction with fluid unresponsiveness, associated with decreased EDV, reduced sarcomere length, and diminished systolic function. Unlike other MMPs that predominantly cleave collagen-III and contribute to cardiac dilatation, thereby increasing sarcomere length, MMP-8 leads to a leftward shift in the EDPVR, resulting in diastolic and systolic dysfunctions.

Efficacy and safety of pulmonary artery catheterization with combined transesophageal echocardiography and pressure waveform: A prospective observational study

ObjectiveThis study investigated whether pulmonary artery catheter placement method with combined transesophageal echocardiography and pressure waveform measurement improve the placement success rate within 5 min and reduce the incidence of arrhythmia during pulmonary artery catheter placement compared to conventional pulmonary artery catheter placement with pressure waveform measurement only. MethodsThis single center prospective observational study included 129 patients scheduled for cardiac surgery. Patients were divided into two groups. In the conventional group, the pulmonary artery catheter was placed by monitoring the pressure waveform and the length of placement; in the combination group, not only were the pressure waveform and the length monitored but also the following transesophageal echocardiography images: “mid esophageal bicaval view,” " mid esophageal modified bicaval view,” a mirror image of “mid esophageal 4 chamber view,” “mid esophageal right ventricular inflow-outflow view,” and “mid esophageal ascending aortic short axis view." ResultsA 1:1 propensity score matching was used to adjust for confounding factors. The success rates of pulmonary artery catheter placement within 5 min in the conventional and combination groups were 85.5 % vs. 97.8 % (p = 0.032) before matching, and 73.7 % vs. 100 % (p = 0.001) after matching. The incidences of arrhythmias in the conventional and combination groups were 28.9 % vs. 17.4 % (p = 0.20) before matching, and 28.9 % vs. 18.4 % (p = 0.42) after matching. ConclusionPulmonary artery catheter placement with transesophageal echocardiography had a significantly higher rate of successful placement within 5 min, but no significant differences were observed in the incidences of arrhythmias.

Left atrial fractional shortening in cats: a comparison between two echocardiographic views

Introduction/objectivesLeft atrial fractional shortening (LAFS%) is a widely used index of left atrial systolic function in cats that has been shown to predict development of hypertrophic cardiomyopathy (HCM) and cardiac mortality. It can be determined by two methods: from an M-mode right parasternal short-axis view (LAFS%RPSA-MM) or two-dimensional right parasternal long-axis four-chamber view (LAFS%RPLA-2D). We aimed to assess the agreement between LAFS%RPSA-MM and LAFS%RPLA-2D in cats and to evaluate the correlation between LAFS%RPSA-MM and LAFS%RPLA-2D and left ventricular systolic performance. Animals, materials, and methodsOne hundred and seventeen cats were enrolled in the study: 40 control, 41 HCM stage B (asymptomatic), and 36 HCM stage C (symptomatic) cats. This was a retrospective case–control study. Bland–Altman analysis was used to assess agreement between LAFS%RPSA-MM and LAFS%RPLA-2D across the whole cohort and in cats with asymptomatic and symptomatic HCM. Correlation analysis was used to assess associations between LAFS% methods and forward aortic flow, left ventricular fractional shortening, and aortic root motion. ResultsThe LAFS% determined by LAFS%RPSA-MM and LAFS%RPLA-2D was similar (P=0.8), but Bland–Altman analysis showed wide limits of agreement between methods. There was a good correlation between LAFS%RPSA-MM and LAFS%RPLA-2D and aortic root motion (r = 0.78 and r = 0.71, respectively) and a fair correlation with left ventricular fractional shortening (r = 0.31 and r = 0.29, respectively). None of the methods showed a correlation with indices of aortic flow. ConclusionsOur study suggests a poor agreement between LAFS%RPSA-MM and LAFS%RPLA-2D, and thus, these methods should not be used interchangeably. Both echocardiographic methods showed good correlation with aortic root motion.

Deep Learning Based Automatic Left Ventricle Segmentation from the Transgastric Short-Axis View on Transesophageal Echocardiography: A Feasibility Study.

Segmenting the left ventricle from the transgastric short-axis views (TSVs) on transesophageal echocardiography (TEE) is the cornerstone for cardiovascular assessment during perioperative management. Even for seasoned professionals, the procedure remains time-consuming and experience-dependent. The current study aims to evaluate the feasibility of deep learning for automatic segmentation by assessing the validity of different U-Net algorithms. A large dataset containing 1388 TSV acquisitions was retrospectively collected from 451 patients (32% women, average age 53.42 years) who underwent perioperative TEE between July 2015 and October 2023. With image preprocessing and data augmentation, 3336 images were included in the training set, 138 images in the validation set, and 138 images in the test set. Four deep neural networks (U-Net, Attention U-Net, UNet++, and UNeXt) were employed for left ventricle segmentation and compared in terms of the Jaccard similarity coefficient (JSC) and Dice similarity coefficient (DSC) on the test set, as well as the number of network parameters, training time, and inference time. The Attention U-Net and U-Net++ models performed better in terms of JSC (the highest average JSC: 86.02%) and DSC (the highest average DSC: 92.00%), the UNeXt model had the smallest network parameters (1.47 million), and the U-Net model had the least training time (6428.65 s) and inference time for a single image (101.75 ms). The Attention U-Net model outperformed the other three models in challenging cases, including the impaired boundary of left ventricle and the artifact of the papillary muscle. This pioneering exploration demonstrated the feasibility of deep learning for the segmentation of the left ventricle from TSV on TEE, which will facilitate an accelerated and objective alternative of cardiovascular assessment for perioperative management.

Radial artery catheterization using a novel T-type ultrasound probe: a single-center randomized study.

Ultrasound guidance has been reported to facilitate radial artery catheterization compared with the palpation method. However, a recent meta-analysis showed that there was not significant differences in the first attempt success rate between the long-axis in-plane (LA-IP) method and the short-axis out-of-plane method. In 2023, we started using a novel T-type probe. We can recognize the needle first during the radial artery access with the short-axis view and then dose it with the long-axis view using the T-type probe. Therefore, we hypothesized that the T-type probe-guided method might heighten the first attempt success rate in radial artery catheterization, even for non-expert practitioners, compared with the LA-IP technique. One hundred and fifty adult patients, older than 20years, ASA I to III, were randomly assigned to the T-type probe-guided group (Group T: n = 75) or the LA-IP group (Group L: n = 75). The primary outcome was the first attempt success rate. The first attempt success rate in Group T (49/71, 69%) was significantly higher than that in Group L (31/68, 46%) (p = 0.0062). The present study showed that the T-type probe might facilitate the radial artery catheterization rather than the LA-IP method.

MRI Assessment of Diastolic Dysfunction in People Living With the Human Immunodeficiency Virus: Correlation With Markers of Disease Activity.

Despite the advent of combination antiretroviral therapy, people living with human immunodeficiency virus (PLWH) are at an increased risk for cardiac disease. To explore the presence and extent of diastolic atrial and left ventricular dysfunction in PLWH using cardiac MRI in correlation with clinical markers of disease activity. Prospective. A total of 163 participants comprising 101 HIV-infected individuals (age: 52 years [42-62 years]; 92% male) and 62 age- and sex-matched healthy volunteers (age: 51 years [30-72 years]; 85% male). 3.0 T, cardiac MRI including balanced steady-state free precession (SSFP) for the short-axis, two-, three-, and four-chamber views were performed. Assessment of cardiac function and strain analysis were accomplished by CVI42 software. Blood samples for CD4+ T cells and cardiac risk factors were also collected before MRI. Independent t tests, Mann-Whitney U test, Pearson's correlation analysis, and multivariate linear analyses (significance level: P < 0.05). PLWH had a significantly larger left atrial volume maximum index (LAVImax: 32.6 ± 8.7 vs. 28.7 ± 8.1 mL/m2), minimum (LAVImin: 14.8 ± 5.5 vs. 11.5 ± 5.4 mL/m2,), and prior to atrial contraction (LAVIpre-a: 23.4 ± 6.7 vs. 19.7 ± 7.2 mL/m2) as compared to healthy volunteers. The LA reservoir (LAtEF: 55.0 ± 10.2 vs. 61.4 ± 10.4; Sls: 29.0 ± 8.1 vs. 33.8 ± 11.8), conduit (LApEF: 28.4 ± 8.2 vs. 32.3 ± 11.3, P = 0.01; Sle: 16.3 ± 6.5 vs. 18.9 ± 8.2), and booster pump function (LAaEF: 37.4 ± 12.4 vs. 42.7 ± 13.1, P = 0.01, Sla: 12.7 ± 5.1 vs. 14.9 ± 5.7) were all significant impaired in PLWH. Global circumferential left ventricular diastolic strain rate (LVGCS-d) was significantly lower in the HIV patients. Multivariate analysis results showed that Nadir CD4+ T cells had a significant adverse association with LVGCS-d (β = 0.51). LA structure abnormalities and LV diastolic dysfunction were manifested in PLWH, with Nadir CD4+ T cell counts potentially serving as a risk factor for early cardiac diastolic dysfunction. 2 TECHNICAL EFFICACY: Stage 3.

The 3-year follow-up of a fully biodegradable implantable device closure for perimembranous ventricular septal defects in children using echocardiography.

The aim of this study was to investigate the morphologic changes of a novel fully biodegradable implantable device after closing a perimembranous ventricular septal defect (Pm-VSD) and to evaluate the effect of the occluder on the myocardial function in patients during a 3-year follow-up period. One-year, 2-year, and 3-year follow-ups were carried out after implantation with a total of 30 Pm-VSD patients who had successful closure by the fully biodegradable occluder. In total, 30 healthy children were enrolled as controls. At discharge and at every follow-up visit, the lengths of the left and right discs of the novel device were measured in the apical three- and four-chamber as well as short-axis views. At the end of the follow-up, using three-dimensional speckle-tracking conditions, the values of myocardial deformation, including global longitudinal strain, global circumferential strain, and global area strain, were acquired. The fully bioabsorbable double-disc occluder gradually decreased over time and was eventually invisible under echocardiographic scanning during the follow-up (p < 0.05). At the end of the third year, there were no significant differences in the myocardial deformation parameters between the cases implanted with the novel devices and the controls; no significant differences were found between the basal segments of the ventricle septa and that of the left ventricle (LV) free wall among the patients who completed the Pm-VSD closure using the fully biodegradable occluder (p > 0.05). The novel fully biodegradable occluder is a safe, effective, and perfect alternative for the treatment of VSD. Echocardiography plays a crucial role in the follow-up of this new type of occluder implantation.

Increasing region of interest width reduces neonatal circumferential strain.

There is growing interest in speckle tracking echocardiography-derived strain as a measure of left ventricular function in neonates. However, knowledge gaps remain regarding the effect of image acquisition and processing parameters on circumferential strain measurements. The aim of this study was to evaluate the effect of using different region of interest (ROI) widths on speckle tracking derived circumferential strain in healthy neonates. Thirty healthy-term-born neonates were examined with speckle-tracking echocardiography in the short-axis view. Circumferential strain values were acquired and compared using two different ROI widths. Furthermore, strain values in the different vendor-defined wall layers were also compared. Increasing ROI width led to a decrease in global circumferential strain (GCS) in the midwall and epicardial layers, the respective decreases in strain being -23.4±.6% to -22.0±1.1%, p<.0001 and 18.5±1.7% to -15.6±2.0%, p<.0001. Segmental analyses were consistent with these results, apart from two segments in the midwall. There was no statistically significant effect on strain for the endocardial layer. A gradient was seen where strain increased from the epicardial to endocardial layers. Increasing ROI width led to a decrease in GCS in the midwall and epicardium. There is an increase in circumferential strain when moving from the epicardial toward the endocardial layer. Clinicians wishing to implement circumferential strain into their practice should consider ROI width variation as a potential confounder in their measurements.