Publications by authors named "Darwin Yeung"

• Multimodality imaging of cardiac masses is needed for comprehensive evaluation. • Isolated cardiac RDD is reported to occur in 0.1% to 0.

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Left ventricular (LV) geometric patterns aid clinicians in the diagnosis and prognostication of various cardiomyopathies. The aim of this study is to assess the accuracy and reproducibility of LV dimensions and wall thickness using deep learning (DL) models. A total of 30,080 unique studies were included; 24,013 studies were used to train a convolutional neural network model to automatically assess, at end-diastole, LV internal diameter (LVID), interventricular septal wall thickness (IVS), posterior wall thickness (PWT), and LV mass.

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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.

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Hypertrophic cardiomyopathy (HCM) is a common genetic disorder with a well described risk of sudden cardiac death; however, risk stratification has remained a challenge. Recently, novel parameters in cardiac magnetic resonance imaging (CMR) have shown promise in helping to improve upon current risk stratification paradigms. In this manuscript, we have reviewed novel CMR risk markers and their utility in HCM.

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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.

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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.

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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.

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Aims: Aortic stenosis (AS) induces characteristic changes in left ventricular (LV) mechanics that can be reversed after aortic valve replacement (AVR). We aimed to comprehensively characterize LV mechanics before and after AVR in patients with severe AS and identify predictors of short-term functional recovery and long-term survival.

Methods And Results: We prospectively performed comprehensive strain analysis by 2D speckle-tracking echocardiography in 88 patients with severe AS and LV ejection fraction ≥50% (mean age 71 ± 12 years, 42% female) prior to and within 7 days after AVR.

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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.

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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.

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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.

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The diagnostic accuracy of the cardiothoracic ratio on chest X-ray to detect left ventricular (LV) enlargement has not been well defined despite its traditional association with cardiomegaly. We aimed to determine whether the cardiothoracic ratio can accurately predict LV enlargement based on indexed linear measurements of the LV on transthoracic echocardiography (TTE). We included consecutive patients who had a TTE and a posteroanterior chest X-ray performed within 90 days of each other at a tertiary care center.

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Limited views are often obtained in the setting of cardiac ultrasound, however, the likelihood of missing left ventricular (LV) dysfunction based on a single view is not known. We sought to determine the echo views that were least likely to miss LV systolic dysfunction in consecutive transthoracic echocardiograms (TTEs). Structured data from TTEs performed at 2 hospitals from September 25, 2017, to January 15, 2019, were screened.

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Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations in the galactosidase A (GLA) gene that result in deficient galactosidase A enzyme and subsequent accumulation of glycosphingolipids throughout the body. The result is a multi-system disorder characterized by cutaneous, corneal, cardiac, renal, and neurological manifestations. Increased left ventricular wall thickness represents the predominant cardiac manifestation of FD.

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Objective: To keep health care providers, in response to the ongoing coronavirus disease 2019 (COVID-19) pandemic, informed about the medications that have been proposed to treat the disease and the evidence supporting their use.

Quality Of Evidence: A narrative review of medications most widely used to treat COVID-19 was conducted, outlining the best available evidence for each pharmacologic treatment to date. Searches were performed in PubMed, EMBASE, and MEDLINE using key words and , as well as related terms.

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Background: Transseptal access for large sheaths may be encumbered by tissue resistance against the sheath-dilator stepped interface. The ExpanSure Large Access Transseptal Dilator (Baylis Medical) is designed as a single introducer and dilation device with a smooth sheath-dilator transition to support transseptal puncture. It may facilitate ease and efficiency of interatrial crossing.

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We developed a machine learning model for efficient analysis of echocardiographic image quality in hospitalized patients. This study applied a machine learning model for automated transthoracic echo (TTE) image quality scoring in three inpatient groups. Our objectives were: (1) Assess the feasibility of a machine learning model for echo image quality analysis, (2) Establish the comprehensiveness of real-world TTE reporting by clinical group, and (3) Determine the relationship between machine learning image quality and comprehensiveness of TTE reporting.

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Background: Echocardiographic assessment of diastolic function is complex but can aid in the diagnosis of heart failure, particularly in patients with preserved ejection fraction. In 2016, the American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) published an updated algorithm for the evaluation of diastolic function. The objective of our study was to assess its impact on diastolic function assessment in a real-world cohort of echo studies.

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Background: Patients with heart failure with preserved ejection fraction (HFpEF) may have elevated left ventricular filling pressure with exercise (LVFP-ex), despite normal LVFP at rest. The aim of this study was to assess the diagnostic value of resting left atrial strain (LAS) in detecting elevated LVFP-ex in patients with dyspnea evaluated on exercise stress echocardiography.

Methods: Two-dimensional speckle-tracking analysis for LAS was performed in 669 consecutive patients (mean age, 64 ± 14 years; 53% men) who underwent treadmill echocardiographic evaluation and had left ventricular ejection fractions ≥ 50%.

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Background: Ventricular strain measurements vary depending on cardiac chamber (left ventricle [LV] or right ventricle [RV]), type of strain (longitudinal, circumferential, or radial), ventricular level (basal, mid, or apical), myocardial layer (endocardial or epicardial), and software used for analysis, among other demographic factors such as age and gender. Here, we present an analysis of ventricular strain taking all of these variables into account in a cohort of patients with no structural heart disease using a vendor-independent speckle-tracking software.

Methods: LV and RV full-thickness strain parameters were retrospectively measured in 102 patients (mean age 39 ± 15 years; 62% female).

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Animal studies suggest that decreased vascular mitochondrial DNA copy number can promote hypertension. We conducted a chart review of blood pressure and hemodynamics in patients with either mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS, n = 36) or individuals with variants in the mitochondrial DNA polymerase gamma (POLG, n = 26). The latter included both pathogenic variants and variants of unknown significance (VUS).

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