1,843 research outputs found
Echocardiographic assessment of a cardiac lymphoma: beyond two-dimensional imaging
Lymphoma is usually recognized as the third most frequent metastatic malignancy involving the heart. In recent years, the incidence of cardiac lymphoma has increased, mainly because of HIV-infected patients. We present a case of secondary cardiac lymphoma in an HIV patient presenting with heart failure. Transthoracic echocardiography showed increased left ventricular (LV) wall thickness and an extensive mass in the right cavities with involvement of the tricuspid annulus (Figure 1). Doppler tissue imaging (DTI) showed reduced systolic and diastolic velocities at mitral and tricuspid annulus, compatible with systolic and diastolic myocardial dysfunction, likely owing to infiltration. After 2 weeks of chemotherapy, repeated exam showed significant reduction of the tumour mass and of the LV wall thickness, as well as normalized systolic and diastolic velocities at mitral and tricuspid annulus, as assessed by DTI. Use of transthoracic echocardiography, mostly two-dimensional imaging, has been described for several years for the diagnosis of cardiac involvement as well as for the assessment of tumour regression in response to chemotherapy. The present case report highlights the potential utility of other echocardiographic modalities, particularly DTI, for the assessment of cardiac lymphoma but also for monitoring the tumour response to adequate therapy
Deep Learning in Cardiology
The medical field is creating large amount of data that physicians are unable
to decipher and use efficiently. Moreover, rule-based expert systems are
inefficient in solving complicated medical tasks or for creating insights using
big data. Deep learning has emerged as a more accurate and effective technology
in a wide range of medical problems such as diagnosis, prediction and
intervention. Deep learning is a representation learning method that consists
of layers that transform the data non-linearly, thus, revealing hierarchical
relationships and structures. In this review we survey deep learning
application papers that use structured data, signal and imaging modalities from
cardiology. We discuss the advantages and limitations of applying deep learning
in cardiology that also apply in medicine in general, while proposing certain
directions as the most viable for clinical use.Comment: 27 pages, 2 figures, 10 table
Late-Onset Prosthetic Endocarditis with Paraaortic Abscess Caused by Cutibacterium acnes
Cutibacterium acnes, an integral component of the skin’s customary bacterial flora, represents
a Gram-positive anaerobic bacterium characterized by its low virulence. Despite its low virulence,
the pathogen can cause profound-seated infections as well as infections linked to medical devices.
We report a case study of a prosthesis endocarditis accompanied by a paraaortic abscess caused by
C. acnes, a development occurring five years prior to composite aortic root and valve replacement. At
the point of admission, the patient presented with a combination of symptoms hinting at a subacute
progression, such as weight loss, chest pain, and limitations of cardiopulmonary functionality. An
anaerobic pathogen, namely C. acnes, was detected in a singular blood culture vial. Since first-line
imaging modalities such as echocardiography did not reveal any signs of inflammation, and in the
case of a suspected diagnosis for IE, did not show high pretest probability, further diagnostic imaging
such as 18F-FDG PET CT was put to use. Here, a highly elevated glucose metabolism around the
aortic valve ring was detected, pointing to an inflammatory process. The patient received adjusted
intravenous antibiotic therapy over a course of six weeks; he then underwent surgical therapy via
re-replacement of the aortic root and valve using a composite conduit. Advanced microbiological
analyses, including the amplification of PCR and valve sequencing via 16S rDNA, mainly detected
one pathogen: C. acnes. Delayed onset with mild symptoms and laboratory findings is characteristic
of infective endocarditis by C. acnes. Due to its high rate of complications, mortality, and morbidity,
an infection should not be disregarded as contamination. Recommendations from different studies
underline a combination of a positive blood culture and microbiological evidence to differentiate
between contamination and true infection in the case of an infection involving C. acnes. Serial blood
cultures with prolonged incubation, advanced microbiological analyses, and modified Duke criteria
including second-line imaging techniques should be utilized for further evaluation
Cardiac Masses on Cardiac CT: A Review
Cardiac masses are rare entities that can be broadly categorized as either neoplastic or non-neoplastic. Neoplastic masses include benign and malignant tumors. In the heart, metastatic tumors are more common than primary malignant tumors. Whether incidentally found or diagnosed as a result of patients’ symptoms, cardiac masses can be identified and further characterized by a range of cardiovascular imaging options. While echocardiography remains the first-line imaging modality, cardiac computed tomography (cardiac CT) has become an increasingly utilized modality for the assessment of cardiac masses, especially when other imaging modalities are non-diagnostic or contraindicated. With high isotropic spatial and temporal resolution, fast acquisition times, and multiplanar image reconstruction capabilities, cardiac CT offers an alternative to cardiovascular magnetic resonance imaging in many patients. Additionally, cardiac masses may be incidentally discovered during cardiac CT for other reasons, requiring imagers to understand the unique features of a diverse range of cardiac masses. Herein, we define the characteristic imaging features of commonly encountered and selected cardiac masses and define the role of cardiac CT among noninvasive imaging options
Arquiteturas federadas para integração de dados biomédicos
Doutoramento Ciências da ComputaçãoThe last decades have been characterized by a continuous adoption of
IT solutions in the healthcare sector, which resulted in the proliferation
of tremendous amounts of data over heterogeneous systems. Distinct
data types are currently generated, manipulated, and stored, in the
several institutions where patients are treated. The data sharing and an
integrated access to this information will allow extracting relevant
knowledge that can lead to better diagnostics and treatments.
This thesis proposes new integration models for gathering information
and extracting knowledge from multiple and heterogeneous biomedical
sources.
The scenario complexity led us to split the integration problem according
to the data type and to the usage specificity. The first contribution is a
cloud-based architecture for exchanging medical imaging services. It
offers a simplified registration mechanism for providers and services,
promotes remote data access, and facilitates the integration of
distributed data sources. Moreover, it is compliant with international
standards, ensuring the platform interoperability with current medical
imaging devices. The second proposal is a sensor-based architecture
for integration of electronic health records. It follows a federated
integration model and aims to provide a scalable solution to search and
retrieve data from multiple information systems. The last contribution is
an open architecture for gathering patient-level data from disperse and
heterogeneous databases. All the proposed solutions were deployed
and validated in real world use cases.A adoção sucessiva das tecnologias de comunicação e de informação
na área da saúde tem permitido um aumento na diversidade e na
qualidade dos serviços prestados, mas, ao mesmo tempo, tem gerado
uma enorme quantidade de dados, cujo valor científico está ainda por
explorar. A partilha e o acesso integrado a esta informação poderá
permitir a identificação de novas descobertas que possam conduzir a
melhores diagnósticos e a melhores tratamentos clínicos.
Esta tese propõe novos modelos de integração e de exploração de
dados com vista à extração de conhecimento biomédico a partir de
múltiplas fontes de dados.
A primeira contribuição é uma arquitetura baseada em nuvem para
partilha de serviços de imagem médica. Esta solução oferece um
mecanismo de registo simplificado para fornecedores e serviços,
permitindo o acesso remoto e facilitando a integração de diferentes
fontes de dados. A segunda proposta é uma arquitetura baseada em
sensores para integração de registos electrónicos de pacientes. Esta
estratégia segue um modelo de integração federado e tem como
objetivo fornecer uma solução escalável que permita a pesquisa em
múltiplos sistemas de informação. Finalmente, o terceiro contributo é
um sistema aberto para disponibilizar dados de pacientes num contexto
europeu. Todas as soluções foram implementadas e validadas em
cenários reais
Right ventricular outflow tract velocity time integral-to-pulmonary artery systolic pressure ratio: a non-invasive metric of pulmonary arterial compliance differs across the spectrum of pulmonary hypertension.
Pulmonary arterial compliance (PAC), invasively assessed by the ratio of stroke volume to pulmonary arterial (PA) pulse pressure, is a sensitive marker of right ventricular (RV)-PA coupling that differs across the spectrum of pulmonary hypertension (PH) and is predictive of outcomes. We assessed whether the echocardiographically derived ratio of RV outflow tract velocity time integral to PA systolic pressure (RVOT-VTI/PASP) (a) correlates with invasive PAC, (b) discriminates heart failure with preserved ejection-associated PH (HFpEF-PH) from pulmonary arterial hypertension (PAH), and (c) is associated with functional capacity. We performed a retrospective cohort study of patients with PAH (n = 70) and HFpEF-PH (n = 86), which was further dichotomized by diastolic pressure gradient (DPG) into isolated post-capillary PH (DPG \u3c 7 mmHg; Ipc-PH, n = 54), and combined post- and pre-capillary PH (DPG ≥ 7 mm Hg; Cpc-PH, n = 32). Of the 156 patients, 146 had measurable RVOT-VTI or PASP and were included in further analysis. RVOT-VTI/PASP correlated with invasive PAC overall (ρ = 0.61, P \u3c 0.001) and for the PAH (ρ = 0.38, P = 0.002) and HFpEF-PH (ρ = 0.63, P \u3c 0.001) groups individually. RVOT-VTI/PASP differed significantly across the PH spectrum (PAH: 0.13 [0.010-0.25] vs. Cpc-PH: 0.20 [0.12-0.25] vs. Ipc-PH: 0.35 [0.22-0.44]; P \u3c 0.001), distinguished HFpEF-PH from PAH (AUC = 0.72, 95% CI = 0.63-0.81) and Cpc-PH from Ipc-PH (AUC = 0.78, 95% CI = 0.68-0.88), and remained independently predictive of 6-min walk distance after multivariate analysis (standardized β-coefficient = 27.7, 95% CI = 9.2-46.3; P = 0.004). Echocardiographic RVOT-VTI/PASP is a novel non-invasive metric of PAC that differs across the spectrum of PH. It distinguishes the degree of pre-capillary disease within HFpEF-PH and is predictive of functional capacity
Narrative review of the role of artificial intelligence to improve aortic valve disease management
Valvular heart disease (VHD) is a chronic progressive condition with an increasing prevalence in the Western world due to aging populations. VHD is often diagnosed at a late stage when patients are symptomatic and the outcomes of therapy, including valve replacement, may be sub-optimal due the development of secondary complications, including left ventricular (LV) dysfunction. The clinical application of artificial intelligence (AI), including machine learning (ML), has promise in supporting not only early and more timely diagnosis, but also hastening patient referral and ensuring optimal treatment of VHD. As physician auscultation lacks accuracy in diagnosis of significant VHD, computer-aided auscultation (CAA) with the help of a commercially available digital stethoscopes improves the detection and classification of heart murmurs. Although used little in current clinical practice, CAA can screen large populations at low cost with high accuracy for VHD and faciliate appropriate patient referral. Echocardiography remains the next step in assessment and planning management and AI is delivering major changes in speeding training, improving image quality by pattern recognition and image sorting, as well as automated measurement of multiple variables, thereby improving accuracy. Furthermore, AI then has the potential to hasten patient disposal, by automated alerts for red-flag findings, as well as decision support in dealing with results. In management, there is great potential in ML-enabled tools to support comprehensive disease monitoring and individualized treatment decisions. Using data from multiple sources, including demographic and clinical risk data to image variables and electronic reports from electronic medical records, specific patient phenotypes may be identified that are associated with greater risk or modeled to the estimate trajectory of VHD progression. Finally, AI algorithms are of proven value in planning intervention, facilitating transcatheter valve replacement by automated measurements of anatomical dimensions derived from imaging data to improve valve selection, valve size and method of delivery
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