Incidentally identified left ventricular apical aneurysm in a patient with Fabry disease.

Fabry disease is a rare X-linked lysosomal storage disorder caused by a deficiency in the lysosomal enzyme, galactosidase A, that can result in a progressive increase in the left ventricle (LV) wall thickness from glycosphingolipid deposition leading to myocardial fibrosis, conduction abnormalities, arrhythmias, and heart failure. We present a case of a patient with advanced Fabry cardiomyopathy, in whom a small LV apical aneurysm was incidentally discovered on abdominal imaging, which could have easily evaded detection on standard transthoracic echocardiography. The LV apex should be thoroughly interrogated in patients with Fabry cardiomyopathy, as the finding of LV aneurysm could have important management implications with respect to the prevention of stroke and sudden cardiac death.

Point-of-care ultrasound in the COVID-19 era: A scoping review.

In the midst of the COVID-19 pandemic, unprecedented pressure has been added to healthcare systems around the globe. Imaging is a crucial component in the management of COVID-19 patients. Point-of-care ultrasound (POCUS) such as hand-carried ultrasound emerges in the COVID-19 era as a tool that can simplify the imaging process of COVID-19 patients, and potentially reduce the strain on healthcare providers and healthcare resources. The preliminary evidence available suggests an increasing role of POCUS in diagnosing, monitoring, and risk-stratifying COVID-19 patients. This scoping review aims to delineate the challenges in imaging COVID-19 patients, discuss the cardiopulmonary complications of COVID-19 and their respective sonographic findings, and summarize the current data and recommendations available. There is currently a critical gap in knowledge in the role of POCUS in the COVID-19 era. Nonetheless, it is crucial to summarize the current preliminary data available in order to help fill this gap in knowledge for future studies.

Clinical assessment of AF pattern is poorly correlated with AF burden and post ablation outcomes: A CIRCA-DOSE sub-study.

BACKGROUND: Contemporary guidelines recommend that atrial fibrillation (AF) be classified into paroxysmal and persistent AF based on clinical assessment, with these categorizations forming the basis of therapeutic recommendations. While pragmatic, clinical assessment may introduce misclassification errors, which may impact treatment decisions. We sought to determine the relationship between AF classification, baseline AF burden, and post-ablation arrhythmia outcomes. DESIGN: The current study is a sub-analysis of a prospective, parallel-group, multicenter, single-blinded randomized clinical trial. All 346 patients enrolled in CIRCA-DOSE received an implantable cardiac monitor a median of 72 days prior to ablation. AF was classified as low burden paroxysmal, high burden paroxysmal, or persistent based on clinical assessment prior to device implantation. Prior to ablation patients were re-classified using the same definitions based on device monitoring data. Correlation between classifications, AF burden, and post-ablation arrhythmia outcomes were assessed. RESULTS: There was poor agreement between clinical and device-based AF classification (Cohen's kappa: 0.192). AF classification derived from pre-ablation continuous monitoring reflected baseline and post-ablation AF burden with greater accuracy and with less overlap between the AF classes (P < 0.01 for all categorical comparisons). Patients objectively classified as "Low Burden" paroxysmal by continuous monitoring data had significantly greater freedom from recurrent AF/AT/AFL compared to those classified as "High Burden" paroxysmal (hazard ratio [HR] 0.57 for AF/AT/AFL recurrence) or persistent AF (HR 0.19 for AF/AT/AFL recurrence). CONCLUSIONS: Classification of AF pattern based on pre-ablation continuous cardiac rhythm monitoring better predicted AF burden and freedom from recurrent AF post ablation. Despite the use of standardized definitions, classification of AF based on clinical assessment did not predict baseline AF burden, post ablation AF burden, or freedom from recurrent AF post ablation. TRIAL REGISTRATION: ClinicalTrials.govNCT01913522.

Focused Cardiac Ultrasonography: Current Applications and Future Directions.

Focused cardiac ultrasonography is performed by clinicians at the bedside and is used in time-sensitive scenarios to evaluate a patient's cardiovascular status when comprehensive echocardiography is not immediately available. This simplified cardiac ultrasonography is often performed by noncardiologists using small, portable devices to augment the physical examination, triage patients, and direct management in both critical care and outpatient settings. However, as the use of focused cardiac ultrasonography continues to expand, careful consideration is required regarding training, scope of practice, impact on patient outcomes, and medicolegal implications. In this review, we examine some of the challenges with rapid uptake of this technique and explore the benefits and potential risk of focused cardiac ultrasonography. We propose possible mechanisms for cross-specialty collaboration, quality improvement, and oversight.

Echocardiographic Diastolic Stress Testing: What Does It Add?

PURPOSE OF REVIEW: Diastolic stress echocardiography may help facilitate the attribution of exertional dyspnea to cardiac and non-cardiac disease. It represents a non-invasive hemodynamic test to assess the patients with unexplained dyspnea. It can improve the diagnosis of heart failure with preserved ejection fraction (HFpEF) or diastolic heart failure. RECENT FINDINGS: A number of studies have validated exercise E/e' as a measure of left ventricular (LV) filling pressure against invasively measured LV filling pressure using simultaneous exercise echocardiography-catheterization studies. Addition of E/e' during exercise echocardiography improved sensitivity for diagnosis of HFpEF compared with resting assessment alone, and its specificity can be improved if tricuspid regurgitation velocity also increases above the normal range with exercise. The independent prognostic value of exercise E/e' has also been well delineated in a number of studies. Diastolic stress exercise echocardiography should be considered for all patients with unexplained or exertional dyspnea and normal diastolic filling pressure or grade 1 diastolic dysfunction on resting echocardiography. Addition of diastolic assessment with exercise echocardiography improves the sensitivity of the test in patients with dyspnea and there are sufficient data to integrate diastolic exercise test into our clinical practice.

Clinical presentation of patients with spontaneous coronary artery dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an infrequent but important cause of myocardial infarction (MI) especially in younger women. However, the clinical presentation and the acuity of symptoms prompting invasive management in SCAD patients have not been described. Understanding these presenting features may improve SCAD diagnosis and management. METHODS: We reviewed SCAD patients who were prospectively followed at the Vancouver General Hospital SCAD Clinic. Their presenting symptoms and unstable features were obtained from detailed clinical histories and hospital admission documentation. Baseline characteristics, predisposing and precipitating conditions, angiographic findings, management strategies, in-hospital, and long-term events were recorded prospectively. RESULTS: We included 196 SCAD patients who had complete documentation of their presenting symptoms. The majority were women (178/196; 90.8%) and all presented with MI (24.0% STEMI). The most frequent presenting symptom was chest discomfort, reported by 96%. Other symptoms included arm pain (49.5%), neck pain (22.1%), nausea or vomiting (23.4%), diaphoresis (20.9%), dyspnea (19.3%), and back pain (12.2%). Ventricular tachycardia/fibrillation occurred in 8.1% (16/196), with 1.0% having cardiac arrest. The time from symptom onset to hospital presentation was 1.1 ± 3.0 days. NSTEMI patients had longer delay for coronary angiography compared with STEMI (2.0 ± 2.5 days vs. 0.8 ± 1.7 days, P = 0.002). Overall, 34.2% had unstable symptoms upon arrival for coronary angiography. Those with unstable symptoms were more likely to undergo repeat angiography (65.7% vs. 50.4%, P = 0.049), and repeat or unplanned revascularization (14.9% vs. 5.4%, P = 0.033) during acute hospitalization. CONCLUSION: Chest discomfort was the most frequent presenting symptom with SCAD and one-third had unstable symptoms prompting urgent invasive angiography. © 2017 Wiley Periodicals, Inc.

Atrial fibrillation and heart failure: cause or effect?

Atrial fibrillation (AF) and heart failure (HF) are two epidemics of the century that have a close and complex relationship. The mechanisms underlying this association remain an area of ongoing intense research. In this review, we will describe the relationship between these two public health concerns, the mechanisms that fuel the development and perpetuation of both, and the evolving concepts that may revolutionize our approach to this dual epidemic.

Prognostic Significance of Elevated Left Ventricular Filling Pressures with Exercise: Insights from a Cohort of 14,338 Patients.

BACKGROUND: Exercise echocardiography can assess for cardiovascular causes of dyspnea other than coronary artery disease. However, the prevalence and prognostic significance of elevated left ventricular (LV) filling pressures with exercise is understudied. METHODS: We evaluated 14,338 patients referred for maximal symptom-limited treadmill echocardiography. In addition to assessment of LV regional wall motion abnormalities (RWMAs), we measured patients' early diastolic mitral inflow (E), septal mitral annulus relaxation (e'), and peak tricuspid regurgitation velocity before and immediately after exercise. RESULTS: Over a mean follow-up of 3.3 ± 3.4 years, patients with E/e' ≥15 with exercise (n = 1,323; 9.2%) had lower exercise capacity (7.3 ± 2.1 vs 9.1 ± 2.4 metabolic equivalents, P < .0001) and were more likely to have resting or inducible RWMAs (38% vs 18%, P < .0001). Approximately 6% (n = 837) had elevated LV filling pressures without RWMAs. Patients with a poststress E/e' ≥15 had a 2.71-fold increased mortality rate (2.28-3.21, P < .0001) compared with those with poststress E/e' ≤ 8. Those with an E/e' of 9 to 14, while at lower risk than the E/e' ≥15 cohort (hazard ratio [HR] = 0.58 [0.48-0.69]; P < .0001), had higher risk than if E/e' ≤8 (HR = 1.56 [1.37-1.78], P < .0001). On multivariable analysis, adjusting for age, sex, exercise capacity, LV ejection fraction, and presence of pulmonary hypertension with stress, patients with E/e' ≥15 had a 1.39-fold (95% CI, 1.18-1.65, P < .0001) increased risk of all-cause mortality compared with patients without elevated LV filling pressures. Compared with patients with E/e' ≤ 15 after exercise, patients with E/e' ≤15 at rest but elevated after exercise had a higher risk of cardiovascular death (HR = 8.99 [4.7-17.3], P < .0001). CONCLUSION: Patients with elevated LV filling pressures are at increased risk of death, irrespective of myocardial ischemia or LV systolic dysfunction. These findings support the routine incorporation of LV filling pressure assessment, both before and immediately following stress, into the evaluation of patients referred for exercise echocardiography.

Automated Atrial Fibrillation Diagnosis by Echocardiography without ECG: Accuracy and Applications of a New Deep Learning Approach.

BACKGROUND: Automated rhythm detection on echocardiography through artificial intelligence (AI) has yet to be fully realized. We propose an AI model trained to identify atrial fibrillation (AF) using apical 4-chamber (AP4) cines without requiring electrocardiogram (ECG) data. METHODS: Transthoracic echocardiography studies of consecutive patients ≥ 18 years old at our tertiary care centre were retrospectively reviewed for AF and sinus rhythm. The study was first interpreted by level III-trained echocardiography cardiologists as the gold standard for rhythm diagnosis based on ECG rhythm strip and imaging assessment, which was also verified with a 12-lead ECG around the time of the study. AP4 cines with three cardiac cycles were then extracted from these studies with the rhythm strip and Doppler information removed and introduced to the deep learning model ResNet(2+1)D with an 80:10:10 training-validation-test split ratio. RESULTS: 634 patient studies (1205 cines) were included. After training, the AI model achieved high accuracy on validation for detection of both AF and sinus rhythm (mean F1-score = 0.92; AUROC = 0.95). Performance was consistent on the test dataset (mean F1-score = 0.94, AUROC = 0.98) when using the cardiologist's assessment of the ECG rhythm strip as the gold standard, who had access to the full study and external ECG data, while the AI model did not. CONCLUSIONS: AF detection by AI on echocardiography without ECG appears accurate when compared to an echocardiography cardiologist's assessment of the ECG rhythm strip as the gold standard. This has potential clinical implications in point-of-care ultrasound and stroke risk stratification.

Validation of machine learning models for estimation of left ventricular ejection fraction on point-of-care ultrasound: insights on features that impact performance.

BACKGROUND: Machine learning (ML) algorithms can accurately estimate left ventricular ejection fraction (LVEF) from echocardiography, but their performance on cardiac point-of-care ultrasound (POCUS) is not well understood. OBJECTIVES: We evaluate the performance of an ML model for estimation of LVEF on cardiac POCUS compared with Level III echocardiographers' interpretation and formal echo reported LVEF. METHODS: Clinicians at a tertiary care heart failure clinic prospectively scanned 138 participants using hand-carried devices. Video data were analyzed offline by an ML model for LVEF. We compared the ML model's performance with Level III echocardiographers' interpretation and echo reported LVEF. RESULTS: There were 138 participants scanned, yielding 1257 videos. The ML model generated LVEF predictions on 341 videos. We observed a good intraclass correlation (ICC) between the ML model's predictions and the reference standards (ICC = 0.77-0.84). When comparing LVEF estimates for randomized single POCUS videos, the ICC between the ML model and Level III echocardiographers' estimates was 0.772, and it was 0.778 for videos where quantitative LVEF was feasible. When the Level III echocardiographer reviewed all POCUS videos for a participant, the ICC improved to 0.794 and 0.843 when only accounting for studies that could be segmented. The ML model's LVEF estimates also correlated well with LVEF derived from formal echocardiogram reports (ICC = 0.798). CONCLUSION: Our results suggest that clinician-driven cardiac POCUS produces ML model LVEF estimates that correlate well with expert interpretation and echo reported LVEF.

Pericardial effusion and systemic capillary leak syndrome late post-SARS-CoV-2 vaccination.

We report an interesting case of pericardial effusion associated with idiopathic systemic capillary leak syndrome (ISCLS) following administration of SARS-CoV-2 vaccine. This patient initially presented with dyspnoea and chest pain, with non-pitting oedema and clear lung fields. The diagnosis of ISCLS was made based on the clinical syndrome and laboratory evidence of polycythaemia and hypoalbuminaemia. An enlarging pericardial effusion was diagnosed on transthoracic echocardiogram. Daily point-of-care ultrasound (POCUS)-guided volume management and serial transthoracic echocardiograms contributed to avoidance of refractory shock, cardiac tamponade and critical care admission.

Quantification of pleural effusions by two-dimensional transthoracic echocardiography.

PURPOSE: There is lack of validated methods for quantifying the size of pleural effusion from standard transthoracic (TTE) windows. The purpose of this study is to determine whether pleural effusion (Peff) measured from routine two-dimensional (2D) TTE views correlate with chest radiograph (CXR). MATERIALS AND METHODS: We retrospectively identified all inpatients who underwent a TTE and CXR within 2 days in a large tertiary care center. Peff was measured on TTE from parasternal long axis (PLAX), apical four-chamber (A4C), and subcostal views and on CXR. Logistic regression models were used determine optimal cut points to predict moderate or greater Peff. RESULTS: In 200 patients (mean age 69.3 ± 14.3 years, 49.5% female), we found statistically significant associations between Peff size assessed by all TTE views and CXR, with weak to moderate correlation (PLAX length: 0.21 (95% CI [0.05, 0.35]); PLAX depth: 0.21 (95% CI [0.05, 0.35]); A4C left: 0.31 (95% CI [0.13, 0.46]); A4C right: 0.39 (95% CI [0.17, 0.57]); subcostal: 0.38 (95% CI [0.07, 0.61]). The best TTE thresholds for predicting moderate or greater left-sided Peff on CXR was PLAX length left > = 8.6 cm (sensitivity 78%, specificity 54%, PPV 26%, and NPV 92%). The best TTE thresholds for predicting moderate or greater right-sided Peff on CXR was A4C right > = 2.6 cm (sensitivity 87%, specificity 60%, PPV 37%, and NPV 94%). CONCLUSIONS: We identified statistically significant associations with Peff size measured on TTE and CXR. The predictive ability of TTE to identify moderate or large pleural effusion is limited.

Machine learning derived echocardiographic image quality in patients with left ventricular systolic dysfunction: insights on the echo views of greatest image quality.

We sought to determine the cardiac ultrasound view of greatest quality using a machine learning (ML) approach on a cohort of transthoracic echocardiograms (TTE) with abnormal left ventricular (LV) systolic function. We utilize an ML model to determine the TTE view of highest quality when scanned by sonographers. A random sample of TTEs with reported LV dysfunction from 09/25/2017-01/15/2019 were downloaded from the regional database. Component video files were analyzed using ML models that jointly classified view and image quality. The model consisted of convolutional layers for extracting spatial features and Long Short-term Memory units to temporally aggregate the frame-wise spatial embeddings. We report the view-specific quality scores for each TTE. Pair-wise comparisons amongst views were performed with Wilcoxon signed-rank test. Of 1,145 TTEs analyzed by the ML model, 74.5% were from males and mean LV ejection fraction was 43.1 ± 9.9%. Maximum quality score was best for the apical 4 chamber (AP4) view (70.6 ± 13.9%, p<0.001 compared to all other views) and worst for the apical 2 chamber (AP2) view (60.4 ± 15.4%, p<0.001 for all views except parasternal short-axis view at mitral/papillary muscle level, PSAX M/PM). In TTEs scanned by professional sonographers, the view with greatest ML-derived quality was the AP4 view.

Cardiac Phenotyping of SARS-CoV-2 in British Columbia: A Prospective Echo Study With Strain Imaging.

BACKGROUND: There is limited data on the residual echocardiographic findings including strain analysis among post-coronavirus disease (COVID) patients. The aim of our study is to prospectively phenotype post-COVID patients. METHODS: All patients discharged following acute COVID infection were systematically followed in the post-COVID-19 Recovery Clinic at Vancouver General Hospital and St. Paul's Hospital. At 4-18 weeks post diagnosis, patients underwent comprehensive echocardiographic assessment. Left ventricular ejection fraction (LVEF) was assessed by 3D, 2D Biplane Simpson's, or visual estimate. LV global longitudinal strain (GLS) was measured using a vendor-independent 2D speckle-tracking software (TomTec). RESULTS: A total of 127 patients (53% female, mean age 58 years) were included in our analyses. At baseline, cardiac conditions were present in 58% of the patients (15% coronary artery disease, 4% heart failure, 44% hypertension, 10% atrial fibrillation) while the remainder were free of cardiac conditions. COVID-19 serious complications were present in 79% of the patients (76% pneumonia, 37% intensive care unit admission, 21% intubation, 1% myocarditis). Normal LVEF was seen in 96% of the cohort and 97% had normal right ventricular systolic function. A high proportion (53%) had abnormal LV GLS defined as < 18%. Average LV GLS of septal and inferior segments were lower compared to that of other segments. Among patients without pre-existing cardiac conditions, LVEF was abnormal in only 1.9%, but LV GLS was abnormal in 46% of the patients. CONCLUSIONS: Most post-COVID patients had normal LVEF at 4-18 weeks post diagnosis, but over half had abnormal LV GLS.

Antenatal sildenafil treatment attenuates pulmonary hypertension in experimental congenital diaphragmatic hernia.

BACKGROUND: Lung hypoplasia and persistent pulmonary hypertension of the newborn limit survival in congenital diaphragmatic hernia (CDH). Unlike other diseases resulting in persistent pulmonary hypertension of the newborn, infants with CDH are refractory to inhaled nitric oxide (NO). Nitric oxide mediates pulmonary vasodilatation at birth in part via cyclic GMP production. Phosphodiesterase type 5 (PDE5) limits the effects of NO by inactivation of cyclic GMP. Because of the limited success in postnatal management of CDH, we hypothesized that antenatal PDE5 inhibition would attenuate pulmonary artery remodeling in experimental nitrofen-induced CDH. METHODS AND RESULTS: Nitrofen administered at embryonic day 9.5 to pregnant rats resulted in a 60% incidence of CDH in the offspring and recapitulated features seen in human CDH, including structural abnormalities (lung hypoplasia, decreased pulmonary vascular density, pulmonary artery remodeling, right ventricular hypertrophy), and functional abnormalities (decreased pulmonary artery relaxation in response to the NO donor 2-(N,N-diethylamino)-diazenolate-2-oxide). Antenatal sildenafil administered to the pregnant rat from embryonic day 11.5 to embryonic day 20.5 crossed the placenta, increased fetal lung cyclic GMP and decreased active PDE5 expression. Antenatal sildenafil improved lung structure, increased pulmonary vessel density, reduced right ventricular hypertrophy, and improved postnatal NO donor 2-(N,N-diethylamino)-diazenolate-2-oxide-induced pulmonary artery relaxation. This was associated with increased lung endothelial NO synthase and vascular endothelial growth factor protein expression. Antenatal sildenafil had no adverse effect on retinal structure/function and brain development. CONCLUSIONS: Antenatal sildenafil improves pathological features of persistent pulmonary hypertension of the newborn in experimental CDH and does not alter the development of other PDE5-expressing organs. Given the high mortality/morbidity of CDH, the potential benefit of prenatal PDE5 inhibition in improving the outcome for infants with CDH warrants further studies.

VersaCross radiofrequency system reduces time to left atrial access versus conventional mechanical needle.

BACKGROUND: Despite maturing experience, transseptal puncture (TSP) remains a challenging part of percutaneous left atrial appendage closure (LAAC) and has inherent risks and safety concerns in accessing the left atrium (LA). The VersaCross radiofrequency (RF) system (Baylis Medical), a new RF-tipped pigtail wire-based TSP system, may facilitate LA access by serving as an exchange support wire once access is achieved. METHODS: We retrospectively compared TSP safety and procedural efficiency in 10 consecutive LAAC cases using the VersaCross RF system to 10 cases using the conventional BRK1-XS mechanical needle (Abbott Vascular). The safety and time from femoral access to delivery of the device sheath were compared to the conventional workflow using BRK1-XS/SL1. RESULTS: We included consecutive 20 cases between July 2019 and November 2019 (12 with WATCHMAN (Boston Scientific, Natick, MA) and 8 with Amulet (St. Jude Medical, St Paul, MN)). Baseline patient characteristics and procedural details were similar in both groups (VersaCross RF system vs. conventional BRK1-XS mechanical needle). All cases were completed successfully with no procedural or in-hospital complications. VersaCross reduced time from femoral access to TSP [4.1 ± 2.5 min vs. 8.4 ± 4.0 min (p = 0.009)] and time from femoral access to delivery sheath access into LA [6.7 ± 2.4 min vs. 13.4 ± 5.4 min (p = 0.002)] compared to BRK1-XS. CONCLUSIONS: Combining a starter wire, transseptal needle and exchange guidewire in the VersaCross RF system enabled faster LA access, which potentially leads to efficient workflow. Further investigation with larger sample size is warranted to corroborate our findings.

A case report of pericardial constriction with coexisting severe left main coronary artery disease.

Background: Constrictive pericarditis (CP) is a rare condition in which the pericardium becomes progressively fibrotic and non-compliant leading to impaired ventricular filling and overt heart failure. While CP shares many clinical and haemodynamic similarities with restrictive cardiomyopathy, differentiation of these diseases is crucial as CP is potentially curative through pericardiectomy. Here, we present a case of proven pericardial constriction with atypical haemodynamics in a patient presenting with heart failure and severe left main coronary artery disease (CAD). Case summary: A 69-year-old female with a history of hypertension and paroxysmal atrial fibrillation presented with persistent heart failure refractory to diuretics. Ischaemic and infiltrative work-up were found to be negative with magnetic resonance imaging demonstrating trace pericardial fluid and thickening of the pericardium. Echocardiogram and right-heart catheterization demonstrated atypical haemodynamics suggestive of but not conclusive for CP, with coronary angiogram demonstrating severe left main CAD. Ultimately, the patient underwent coronary artery bypass grafting along with pericardiectomy and pericardial biopsy demonstrating constrictive physiology. Discussion: We suspect the inconclusive nature of the echocardiogram and cardiac catheterization was likely secondary to severe CAD impairing left ventricular relaxation and dampening ventricular interdependence. As such, clinicians should consider the possibility of coexistent severe CAD in patients with a clinical suspicion of CP, but inconclusive haemodynamics.

U-LanD: Uncertainty-Driven Video Landmark Detection.

This paper presents U-LanD, a framework for automatic detection of landmarks on key frames of the video by leveraging the uncertainty of landmark prediction. We tackle a specifically challenging problem, where training labels are noisy and highly sparse. U-LanD builds upon a pivotal observation: a deep Bayesian landmark detector solely trained on key video frames, has significantly lower predictive uncertainty on those frames vs. other frames in videos. We use this observation as an unsupervised signal to automatically recognize key frames on which we detect landmarks. As a test-bed for our framework, we use ultrasound imaging videos of the heart, where sparse and noisy clinical labels are only available for a single frame in each video. Using data from 4,493 patients, we demonstrate that U-LanD can exceedingly outperform the state-of-the-art non-Bayesian counterpart by a noticeable absolute margin of 42% in R2 score, with almost no overhead imposed on the model size.

A Novel Continuous Left Ventricular Diastolic Function Score Using Machine Learning.

BACKGROUND: Unlike left ventricular (LV) ejection fraction, which provides a precise, reliable, and prognostically valuable measure of systolic function, there is no single analogous measure of LV diastolic function. OBJECTIVES: We aimed to develop a continuous score to grade LV diastolic function using machine learning modeling of echocardiographic data. METHODS: Consecutive echo studies performed at a tertiary-care center between February 1, 2010, and March 31, 2016, were assessed, excluding studies containing features that would interfere with diastolic function assessment as well as studies in which 1 or more parameters within the contemporary diastolic function assessment algorithm were not reported. Diastolic function was graded based on 2016 American Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACVI) guidelines, excluding indeterminate studies. Machine learning models were trained (support vector machine [SVM], decision tree [DT], XGBoost [XGB], and dense neural network [DNN]) to classify studies within the training set by diastolic dysfunction severity, blinded to the ASE/EACVI classification. The DNN model was retrained to generate a regression model (R-DNN) to predict a continuous LV diastolic function score. RESULTS: A total of 28,986 studies were included; 23,188 studies were used to train the models, and 5,798 studies were used for validation. The models were able to reclassify studies with high agreement to the ASE/EACVI algorithm (SVM, 83%; DT, 100%; XGB, 100%; DNN, 98%). The continuous diastolic function score corresponded well with ASE/EACVI guidelines, with scores of 1.00 ± 0.01 for studies with normal function and 0.74 ± 0.05, 0.51 ± 0.06, and 0.27 ± 0.11 for mild, moderate, and severe diastolic dysfunction, respectively (mean ± 1 SD). A score of <0.91 predicted abnormal diastolic function (area under the receiver operator curve = 0.99), while a score of <0.65 predicted elevated filling pressure (area under the receiver operator curve = 0.99). CONCLUSIONS: Machine learning can assimilate echocardiographic data and generate an automated continuous diastolic function score that corresponds well with current diastolic function grading recommendations.

Loculated Pericardial Effusion: An Uncommon Cause of Left Ventricular Outflow Tract Obstruction.

A patient with a previous lung transplant and aortic valve replacement had progressive dyspnea. He presented with subacute tamponade secondary to a loculated pericardial effusion that caused impaired left ventricular filling and outflow tract obstruction secondary to distortion of the mitral valve apparatus. We demonstrate the imaging features of this presentation. (Level of Difficulty: Intermediate.).