BACKGROUND: Extracting phenotype-representative flow patterns and their associated numerical metrics is a bottleneck in the clinical translation of advanced cardiac flow imaging modalities. We hypothesized that reduced-order models (ROMs) are a suitable strategy for deriving simple and interpretable clinical metrics of intraventricular flow suitable for further assessments. Combined with machine learning (ML) flow-based ROMs could provide new insight to help diagnose and risk-stratify patients.
METHODS: We analyzed 2D color-Doppler echocardiograms of 81 non-ischemic dilated cardiomyopathy (DCM) patients, 51 hypertrophic cardiomyopathy (HCM) patients, and 77 normal volunteers (Control). We applied proper orthogonal decomposition (POD) to build patient-specific and cohort-specific ROMs of LV flow. Each ROM aggregates a low number of components representing a spatially dependent velocity map modulated along the cardiac cycle by a time-dependent coefficient. We tested three classifiers using deliberately simple ML analyses of these ROMs with varying supervision levels. In supervised models, hyperparameter grid search was used to derive the ROMs that maximize classification power. The classifiers were blinded to LV chamber geometry and function. We ran vector flow mapping on the color-Doppler sequences to help visualize flow patterns and interpret the ML results.
RESULTS: POD-based ROMs stably represented each cohort through 10-fold cross-validation. The principal POD mode captured >80 % of the flow kinetic energy (KE) in all cohorts and represented the LV filling/emptying jets. Mode 2 represented the diastolic vortex and its KE contribution ranged from <1 % (HCM) to 13 % (DCM). Semi-unsupervised classification using patient-specific ROMs revealed that the KE ratio of these two principal modes, the vortex-to-jet (V2J) energy ratio, is a simple, interpretable metric that discriminates DCM, HCM, and Control patients. Receiver operating characteristic curves using V2J as classifier had areas under the curve of 0.81, 0.91, and 0.95 for distinguishing HCM vs. Control, DCM vs. Control, and DCM vs. HCM, respectively.
CONCLUSIONS: Modal decomposition of cardiac flow can be used to create ROMs of normal and pathological flow patterns, uncovering simple interpretable flow metrics with power to discriminate disease states, and particularly suitable for further processing using ML.

暂无摘要。

Quadricuspid aortic valve is a rare congenital cardiac anomaly with an incidence of 0.008% to 0.043%. Its clinical course varies depending on cusp anatomy, function, and associated cardiac malformations. It frequently progresses to aortic valve regurgitation that may require surgical valve replacement. Detection has shifted from incidental discovery during autopsies or cardiac surgeries in the early 20th century to various cardiac imaging methods in recent decades. In addition to contributing to the literature, this report supports the use of transesophageal echocardiography more liberally to detect aortic valve abnormalities. The case presents a 48-year-old female patient with an incidentally discovered quadricuspid aortic valve.

The transcatheter edge-to-edge mitral valve repair (TEER) has been recommended as a reliable treatment option for selected patients with severe degenerative and functional mitral regurgitation (MR). Although MR patients with rheumatic etiology were excluded from two significant trials (EVEREST II and COAPT) that established a role for the TEER in degenerative and functional MR. However, it has been reported that the TEER procedure could be safely and effectively performed in carefully selected rheumatic MR patients. Therefore, we share a case report of successfully treating severe rheumatic MR using a novel-designed TEER system (JensClipTM).

暂无摘要。

OBJECTIVE: Although rare, the development of mechanical complications following an acute myocardial infarction is associated with a high morbidity and mortality. Here, we review the clinical features, diagnostic strategy, and treatment options for each of the mechanical complications, with a focus on the role of echocardiography.
RESULTS: The growth of percutaneous structural interventions worldwide has given rise to new non-surgical options for management of mechanical complications. As such, select patients may benefit from a novel use of these established treatment methods. A thorough understanding of the two-dimensional, three-dimensional, color Doppler, and spectral Doppler findings for each mechanical complication is essential in recognizing major causes of hemodynamic decompensation after an acute myocardial infarction. Thereafter, echocardiography can aid in the selection and maintenance of mechanical circulatory support and potentially facilitate the use of a percutaneous intervention.

BACKGROUND: Echocardiographic grading of mitral regurgitation (MR) in mitral valve prolapse (MVP) is challenging. Three-dimensional (3D) vena contracta area (VCA) has been proposed as a valuable method. However, data defining the cutoff values of severity and validation in the subset of patients with MVP are scarce. The aim of this study was to validate the 3D VCA by 3D color-Doppler transesophageal echocardiography (TEE) in patients with MVP and to define the cutoff values of severity grading. The secondary aim was to compare 3D VCA to the effective regurgitant orifice area estimation by proximal isovelocity surface area (EROA-PISA) method.
METHODS: A total of 1,138 patients with at least moderate MR who underwent TEE were included. Three-dimensional VCA was measured, and the cutoff value and area under the curve (AUC) for the prediction of severe MR were estimated by receiver operating characteristic curve using a guideline-suggested multiparametric approach as the reference standard. In a subgroup of patients, 3D regurgitant volume (RV) and 3D fraction were calculated from mitral and left ventricular outflow tract stroke volumes to further validate 3D VCA against a 3D volumetric reference standard.
RESULTS: The optimal 3D VCA cutoff value for predicting severe MR was 0.45 cm2 (specificity, 0.87; sensitivity, 0.90) with an AUC of 0.95 using a multiparametric approach as reference. Three-dimensional VCA had a good linear correlation with EROA-PISA (r = 0.62, P < .05) with larger values compared to EROA-PISA (0.63 cm2 vs 0.44 cm2, P < .05). A cutoff of 0.50 cm2 (AUC of 0.84; sensitivity, 0.78; specificity, 0.78) predicts an EROA-PISA of 0.40 cm2. Three-dimensional VCA had a good linear correlation with 3D RV (r = 0.56, P < .01), with an AUC of 0.86 to predict a 3D fraction >50%.
CONCLUSIONS: The present study suggests 0.45 cm2 as the best cutoff value of 3D VCA to define severe MR in patients with MVP, showing an optimal agreement with the reference standard multiparametric approach and 3D RV.

暂无摘要。

BACKGROUND: The assessment of ventricular secondary mitral regurgitation (v-SMR) severity through effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) calculations using the proximal isovelocity surface area (PISA) method and the two-dimensional echocardiography volumetric method (2DEVM) is prone to underestimation. Accordingly, we sought to investigate the accuracy of the three-dimensional echocardiography volumetric method (3DEVM) and its association with outcomes in v-SMR patients.
METHODS: We included 229 patients (70 ± 13 years, 74% men) with v-SMR. We compared EROA and RegVol calculated by the 3DEVM, 2DEVM, and PISA methods. The end point was a composite of heart failure hospitalization and death for any cause.
RESULTS: After a mean follow-up of 20 ±11 months, 98 patients (43%) reached the end point. Regurgitant volume and EROA calculated by 3DEVM were larger than those calculated by 2DEVM and PISA. Using receiver operating characteristic curve analysis, both EROA (area under the curve, 0.75; 95% CI, 0.68-0.81; P = .008) and RegVol (AUC, 0.75; 95% CI, 0.68-0.82; P = .02) measured by 3DEVM showed the highest association with the outcome at 2 years compared to PISA and 2DEVM (P < .05 for all). Kaplan-Meier analysis demonstrated a significantly higher rate of events in patients with EROA ≥ 0.3 cm2 (cumulative survival at 2 years: 28% ± 7% vs 32% ± 10% vs 30% ± 11%) and RegVol ≥ 45 mL (cumulative survival at 2 years: 21% ± 7% vs 24% ± 13% vs 22% ± 10%) by 3DEVM compared to those by PISA and 2DEVM, respectively. In Cox multivariable analysis, 3DEVM EROA remained independently associated with the end point (hazard ratio, 1.02, 95% CI, 1.00-1.05; P = .02). The model including EROA by 3DEVM provided significant incremental value to predict the combined end point compared to those using 2DEVM (net reclassification index = 0.51, P = .003; integrated discrimination index = 0.04, P = .014) and PISA (net reclassification index = 0.80, P < .001; integrated discrimination index = 0.06, P < .001).
CONCLUSIONS: Effective regurgitant orifice area and RegVol calculated by 3DEVM were independently associated with the end point, improving the risk stratification of patients with v-SMR compared to the 2DEVM and PISA methods.

The concept of disproportionate mitral regurgitation (dispropMR) has been introduced to identify patients with functional mitral regurgitation (MR) who benefit from percutaneous treatment. We aimed to examine echocardiographic characteristics behind this entity. We retrospectively included 172 consecutive patients with reduced left ventricular ejection fraction (LVEF), and more than mild MR referred to clinically indicated echocardiography. According to the proportionality ratio (effective regurgitant orifice area (EROA)/left ventricular end-diastolic volume (LVEDV)) patients were divided into dispropMR and proportionate MR (propMR) group. Potential factors which might affect proportionality definition were analyzed. 55 patients (32%) had dispropMR. Discrepant grading of MR severity was observed when using regurgitant volume (RegVol) by proximal isovelocity surface area (PISA) method or volumetric method, with significant discordance only in dispropMR (p < 0.001). Patients with dispropMR had more frequently left ventricular foreshortened images for LVEDV calculation than patients with propMR (p = 0.003), resulting in smaller LVEDV in dispropMR group. DispropMR group had more substantial dynamic variation of regurgitant flow compared to propMR. Accordingly, EROA was consistently overestimated by standard single-point PISA method compared to serial PISA method. This was more pronounced in dispropMR (bias:10.5 ± 28.3 mm2) compared to propMR group (bias:6.4 ± 12.8 mm2). DispropMR may be found in roughly one third of clinically indicated echocardiographic studies in patients with reduced LVEF and more than mild MR. EROA overestimation due to dynamic variation of regurgitant flow and LVEDV underestimation due to LV foreshortening were more frequently found in dispropMR. Our results indicate that methodological limitations of echocardiographic MR grading could not be neglected in classifying the proportionality of MR.