Rare cardiac tumour-nodular fasciitis

Left ventricular tumour is a rare condition in children. The causes include vegetations, thrombus, and fibroma. 2-year-old asymptomatic female presented with an innocent heart murmur at 6 months of age. Subsequent follow-ups at 18 months of age showed left ventricular mass. Surgical pathology revealed "nodular fasciitis." This type of tumour has never been described in the heart before.

Two-Dimensional and Doppler trans-thoracic echocardiographic patterns of suspected pediatric heart diseases at Tibebe--Ghion specialized Teaching Hospital and Adinas General Hospital, Bahir Dar, North-west Ethiopia:-An experience from an LMIC

BACKGROUND

Transthoracic Echocardiography is the first-line, non-invasive, and accessible imaging modality to evaluate heart disease anatomy, physiology, and hemodynamics. We aim to describe the trans-thoracic echocardiography pattern of pediatric heart diseases and reasons for referral in children referred to Bahir Dar University Tibebe-Ghion Hospital and Adinas General Hospital.

METHOD

A descriptive cross-sectional study of the archived Transthoracic, Two Dimensional, and Doppler Echocardiography assessments of children from birth to fifteen years of age performed between June 2019 to May 2023 was done. Data were collected retrospectively from February 01, 2023 -May 31, 2023. Categorical variables like gender, referral reasons for echocardiography, and patterns of pediatric heart lesions were analyzed in the form of proportions and presented in tables and figures. Discrete variables including age were summarized as means (SD) and medians(IQR).

RESULTS

Out of 3,647 Children enrolled; 1,917 (52.6%) were males and 1,730 (47.4%) were females. The median (IQR) age of children enrolled was 24 months (5 to 96). Cardiac murmur (33%) was the most common reason for echocardiography followed by, Respiratory Distress (18%), Syndromic Child (15%), easy fatigability/ Diaphoresis (14.3%), congestive heart failure (14%), and rheumatic fever (13.2%). Congenital heart defect (CHD) accounts for 70% of all heart diseases, followed by rheumatic heart disease (21%). Isolated ventricular septal defect(VSD) was the most common CHD (21%) followed by isolated Patent ductus arteriosus (15%), isolated atrial septal defect (10%), Isolated atrioventricular septal defect (6%) and isolated pulmonary stenosis (5%). Cyanotic CHD accounts for 11.5% of all heart diseases. Tetralogy of Fallot (30%), d-TGA (20%), and double outlet right ventricle (19%) were the most common cyanotic CHDs.

CONCLUSIONS

In our study, congenital heart lesions are the most common diagnosis and cardiac murmurs are the most common presenting reasons for echocardiography evaluation.

Short-Term Effects of Different Transcatheter Edge-to-Edge Devices on Mitral Valve Geometry

Background Short-term effects on mitral valve (MV) anatomy after transcatheter edge-to-edge repair using the PASCAL system remain unknown. Precise quantification might allow for an advanced analysis of predictors for mean transmitral gradients. Methods and Results Consecutive patients undergoing transcatheter edge-to-edge repair for secondary mitral regurgitation using PASCAL or MitraClip systems were included. Quantification of short-term MV changes throughout the cardiac cycle was performed using peri-interventional 3-dimensional MV images. Predictors for mean transmitral gradients were identified in univariable and multivariable regression analysis. Long-term results were described during 1-year follow-up. A total of 100 patients undergoing transcatheter edge-to-edge repair using PASCAL (n=50) or MitraClip systems (n=50) were included. Significant reductions of anterior-posterior diameter, annular circumference, and area throughout the cardiac cycle were found in both cohorts (P<0.05 for all). Anatomic MV orifice area remained larger in the PASCAL cohort in mid (2.8±1.0 versus 2.4±0.9 cm2; P=0.049) and late diastole (2.7±1.1 versus 2.2±0.8 cm2; P=0.036) compared with the MitraClip cohort. Besides a device-specific profile of independent predictor of mean transmitral gradients, reduction of middiastolic anatomic MV orifice area was identified as an independent predictor in both the PASCAL (β=-0.410; P=0.001) and MitraClip cohorts (β=-0.318; P=0.028). At follow-up, reduction of mitral regurgitation grade to mild or less was more durable in the PASCAL cohort (90% versus 72%; P=0.035). Conclusions PASCAL and MitraClip showed comparable short-term effects on MV geometry. However, PASCAL might better preserve MV function and demonstrated more durable mitral regurgitation reduction during follow-up. Identification of independent predictors for mean transmitral gradients might potentially help to guide device selection in the future.

Parameter-Efficient Densely Connected Dual Attention Network for Phonocardiogram Classification

Cardiac auscultation, exhibited by phonocardiogram (PCG), is a non-invasive and low-cost diagnostic method for cardiovascular diseases (CVDs). However, deploying it in practice is quite challenging, due to the inherent murmurs and a limited number of supervised samples in heart sound data. To solve these problems, not only heart sound analysis based on handcrafted features, but also computer-aided heart sound analysis based on deep learning have been extensively studied in recent years. Though with elaborate design, most of these methods still use additional pre-processing to improve classification performance, which heavily relies on time-consuming experienced engineering. In this article, we propose a parameter-efficient densely connected dual attention network (DDA) for heart sound classification. It combines two advantages simultaneously of the purely end-to-end architecture and enriched contextual representations of the self-attention mechanism. Specifically, the densely connected structure can automatically extract the information flow of heart sound features hierarchically. Alongside, improving contextual modeling capabilities, the dual attention mechanism adaptively aggregates local features with global dependencies via a self-attention mechanism, which captures the semantic interdependencies across position and channel axes respectively. Extensive experiments across stratified 10-fold cross-validation strongly evidence that our proposed DDA model surpasses current 1D deep models on the challenging Cinc2016 benchmark with significant computational efficiency.

Pitfalls of mitral regurgitation assessment in the presence of mitral valve prolapse

Adequate grading of mitral regurgitation (MR) in patients with mitral valve prolapse (MVP) in the presence of mid-late systolic jets can represent a major challenge. In this entity, jets are commonly overestimated by echocardiography. Correct quantification is crucial and highly relevant for the further management and prognosis of these oftentimes young patients. This case points out potential pitfalls and underlines the importance to systematically include qualitative, quantitative, and semi-quantitative parameters into the echocardiographic assessment.

Referring Provider Opinions of Pediatric Cardiology Evaluations Performed by Nurse Practitioners

In the setting of physician shortages, nurse practitioner (NP) roles have evolved, with increasing independence across most healthcare settings. We sought to characterize referring clinician perceptions of NP-performed outpatient pediatric cardiology consultations. We electronically distributed to pediatric and family medicine physicians and NPs in Arkansas our 11-item survey assessing the acceptability of pediatric cardiology consultations being completed by an NP under varying circumstances. Circumstances included seven common referral indications, and the scale offered five answer choices ranging from "definitely unacceptable" to "definitely acceptable". A total of 292 of 1756 (16.6% response rate) referring clinicians responded to the survey. Overall, 57% of responses indicated that NP-completed pediatric cardiology evaluations were either definitely or probably unacceptable. Acceptability was varied by referral indication and referring clinician characteristics. Unacceptability of NP-completed pediatric cardiology evaluations was greatest among family medicine physicians (81%), pediatricians (66%), and clinicians working in solo or two-physician practices (77%) or community hospitals/clinics (71%). If NP evaluation of a murmur included required review with a cardiologist, the unacceptability rate dropped from 50 to 24% (p < 0.0001). Unacceptability was higher in physicians who do not work with NPs (69%) compared to those who do (60%) (pp < 0.0001). Many referring physicians were willing to send patients ≥ 100 miles to ensure evaluation by a pediatric cardiologist. Most referring physicians find pediatric cardiology evaluations performed by NPs to be unacceptable. Requisite review with a cardiologist improved acceptability of NP evaluations. Many referring physicians would send patients much farther to guarantee evaluation by a cardiologist.

Diastolic versus Systolic Left Ventricular Dysfunction as Independent Predictors for Unfavorable Postoperative Evolution in Patients with Aortic Regurgitation Undergoing Aortic Valve Replacement

Background and Objectives: Chronic severe aortic valve disease is associated with important changes in left ventricle (LV) performance associated with eccentric or concentric LV hypertrophy. We aimed to assess the immediate prognostic implications of the type of the LV diastolic filling pattern (LVDFP) compared with LV systolic performance in patients with severe aortic regurgitation (AR) undergoing aortic valve replacement (AVR) and to define the independent echographic predictors for the immediate and long-term prognoses. Materials and Methods: We performed a prospective study enrolling 332 AR patients undergoing AVR, divided into two groups: Group A—201 pts with normal LV systolic function, divided into two subgroups (A1: 129 pts with a nonrestrictive LVDFP and A2: 72 pts with restrictive LVDFP), and Group B—131 pts with LV systolic dysfunction (LV ejection fraction LVEF < 50%), divided into two subgroups (B1: 83 pts with a nonrestrictive LVDFP and B2: 48 pts with restrictive LVDFP). Results: The early postoperative mortality rate was higher in patients with a restrictive LVDFP (11.12% in A2 and 12.5% in B2) compared with normal LV filling (2.32% in A1 and 7.63% in B1, p < 0.0001), regardless of the LVEF. The restrictive LVDFP—defined by at least one of the following echographic parameters: an E/A > 2 with an E wave deceleration time (EDt) < 100 ms; an isovolumetric relaxation time (IVRT) < 60 ms; or an S/D ratio < 1 in the pulmonary vein flow—was an independent predictor for early postoperative mortality, increasing the relative risk by 8.2-fold. Other independent factors associated with early poor prognosis were an LV end-systolic diameter (LVESD) > 58 mm, an age > 75 years, and the presence of comorbidities (chronic obstructive pulmonary disease-COPD or diabetes mellitus). On a medium-term, an unfavorable evolution was associated with: an age > 75 years (RR = 8.1), an LV end-systolic volume (LVESV) > 95 cm3 (RR = 6.7), a restrictive LVDFP (RR = 9.8, p < 0.0002), and pulmonary hypertension (RR = 8.2). Conclusions: The presence of a restrictive LVDFP in patients with AR undergoing AVR is associated with both increased early and medium-term mortality rates. The LV diastolic function is a more reliable parameter for prognosis than LV systolic performance (RR 9.2 versus 2.1). Other independent predictors for increased early postoperative mortality rate were: an age > 75 years, an LVESD > 58 mm, and comorbidities (diabetes mellitus, COPD), and for unfavorable evolution at 2 years postoperatively: an age > 75 years, an LVESV > 95 cm3, and severe pulmonary hypertension.

Spliceosomal profiling identifies EIF4A3 as a novel oncogene in hepatocellular carcinoma acting through the modulation of FGFR4 splicing

INTRODUCTION

Altered splicing landscape is an emerging cancer hallmark; however, the dysregulation and implication of the cellular machinery controlling this process (spliceosome components and splicing factors) in hepatocellular carcinoma (HCC) is poorly known. This study aimed to comprehensively characterize the spliceosomal profile and explore its role in HCC.

METHODS

Expression levels of 70 selected spliceosome components and splicing factors and clinical implications were evaluated in two retrospective and six in silico HCC cohorts. Functional, molecular and mechanistic studies were implemented in three cell lines (HepG2, Hep3B and SNU-387) and preclinical Hep3B-induced xenograft tumours.

RESULTS

Spliceosomal dysregulations were consistently found in retrospective and in silico cohorts. EIF4A3, RBM3, ESRP2 and SRPK1 were the most dysregulated spliceosome elements in HCC. EIF4A3 expression was associated with decreased survival and greater recurrence. Plasma EIF4A3 levels were significantly elevated in HCC patients. In vitro EIF4A3-silencing (or pharmacological inhibition) resulted in reduced aggressiveness, and hindered xenograft-tumours growth in vivo, whereas EIF4A3 overexpression increased tumour aggressiveness. EIF4A3-silencing altered the expression and splicing of key HCC-related genes, specially FGFR4. EIF4A3-silencing blocked the cellular response to the natural ligand of FGFR4, FGF19. Functional consequences of EIF4A3-silencing were mediated by FGFR4 splicing as the restoration of non-spliced FGFR4 full-length version blunted these effects, and FGFR4 inhibition did not exert further effects in EIF4A3-silenced cells.

CONCLUSIONS

Splicing machinery is strongly dysregulated in HCC, providing a source of new diagnostic, prognostic and therapeutic options in HCC. EIF4A3 is consistently elevated in HCC patients and associated with tumour aggressiveness and mortality, through the modulation of FGFR4 splicing.

Atomic force microscopy identifies the alteration of rheological properties of the cardiac fibroblasts in idiopathic restrictive cardiomyopathy

Restrictive cardiomyopathy (RCM) is a rare disease characterized by increased ventricular stiffness and preserved ventricular contraction. Various sarcomere gene variants are known to cause RCM; however, more than a half of patients do not harbor such pathogenic variants. We recently demonstrated that cardiac fibroblasts (CFs) play important roles in inhibiting the diastolic function of cardiomyocytes via humoral factors and direct cell–cell contact regardless of sarcomere gene mutations. However, the mechanical properties of CFs that are crucial for intercellular communication and the cardiomyocyte microenvironment remain less understood. In this study, we evaluated the rheological properties of CFs derived from pediatric patients with RCM and healthy control CFs via atomic force microscopy. Then, we estimated the cellular modulus scale factor related to the cell stiffness, fluidity, and Newtonian viscosity of single cells based on the single power-law rheology model and analyzed the comprehensive gene expression profiles via RNA-sequencing. RCM-derived CFs showed significantly higher stiffness and viscosity and lower fluidity compared to healthy control CFs. Furthermore, RNA-sequencing revealed that the signaling pathways associated with cytoskeleton elements were affected in RCM CFs; specifically, cytoskeletal actin-associated genes (ACTN1, ACTA2, and PALLD) were highly expressed in RCM CFs, whereas several tubulin genes (TUBB3, TUBB, TUBA1C, and TUBA1B) were down-regulated. These results implies that the signaling pathways associated with cytoskeletal elements alter the rheological properties of RCM CFs, particularly those related to CF–cardiomyocyte interactions, thereby leading to diastolic cardiac dysfunction in RCM.

Effects of idiopathic erythrocytosis on the left ventricular diastolic functions and the spectrum of genetic mutations: A case control study

BACKGROUND

We have aimed at exposing left ventricular diastolic functions and the presence of known genetic mutations for familial erythrocytosis, in patients who exhibit idiopathic erythrocytosis.

METHODS

Sixty-four patients with idiopathic erythrocytosis (mean age, 46.4 ± 2.7 years) and 30 age-matched healthy subjects were prospectively evaluated. The regions of interest of the erythropoietin receptor, hemoglobin beta-globin, von Hippel-Lindau, hypoxia-inducible factor 2 alpha, and Egl-9 family hypoxia-inducible factor genes were amplified by PCR. Left ventricular (LV) mass was measured by M-mode and 2-dimensional echocardiography. LV diastolic functions were assessed by conventional echocardiography and tissue Doppler imaging.

RESULTS

As a result of genetic analyses, genetic mutations for familial erythrocytosis were detected in 5 patients. It has been observed in our study that the risk of cardiovascular disorders is higher in patients. Interventricular septum thickness, left atrial diameter, and some diastolic function parameters such as deceleration time and isovolumetric relaxation time have been found to be significantly higher in idiopathic erythrocytosis group than in the controls.

CONCLUSION

This study has shown that LV diastolic functions were impaired in patients with idiopathic erythrocytosis. In this patient group with increased risk of cardiovascular disorders, the frequent genetic mutations have been detected in 5 patients only. Therefore, further clinical investigations are needed as novel genetic mutations may be discovered in patients with idiopathic erythrocytosis because of cardiovascular risk.

Ventricular and Atrial Ejection Fractions are Associated with Mean Compartmental Cavity Volume in Cardiac Disease

Ejection fraction (EF) is considered to provide clinically useful information. Despite its enormous popularity, with more than 75,000 citations in PubMed, only few studies have traced the origin(s) of its foundation. This fact is surprising, as there are perhaps more papers published that criticize EF, than the number of publications that actually provide a solid (mathematical) basis for its alleged applicability. EF depends on two volume determinations, namely end-systolic volume (ESV) and end-diastolic volume (EDV). EF is defined as 1-ESV/EDV, yielding a metric without physical units. Previously we formulated a robust analytical expression for the nonlinear connection between EF and ESV. Here we extend that approach by providing a formula to illustrate that EF is strongly associated with half the sum (HS) of ESV and EDV. HS is not new, but forms a major component in the recently introduced Global Function Index. For 420 heart failure (HF) patients we found for left ventricular angio data: R(ESV, eDv) = 0.92, R(EF, ESV) = -0.90, and R(EF, HS) = -0.65. For echo (33 HF patients stages A, B, C and D): R(EF, HS) = -0.82. For the right atrium (CMRI in 21 acute myocardial infarction patients): R(EF, HS)=-0.65. For the left atrium (N=86) R (EF, hS)=-0.46. ESV indicates the level to which the ventricle is able to squeeze blood out of the cavity via pressure build-up. In contrast, EF refers to relative volume changes, not to the mechanism of pumping action. We conclude that for each cardiac compartment EF borrows its acclaimed attractiveness from the fact that for a wide patient spectrum the ESVand EDV correlate in a fairly linear manner. Attractiveness of EF features a straightforward mathematical derivation, rather than reflecting underlying physiology. Clinical Relevance - Ejection fraction (EF) is found to reflect (mean) ventricular / atrial size, and is primarily associated with end-systolic volume, which variable in turn highly correlates with diastolic volume. As a mathematical construct, EF has little affinity with "function", which is a central concept in physiology.

Streamline-based three-dimensional peak-velocity tracing of transvalvular flow using four-dimensional flow cardiac magnetic resonance imaging for left ventricular diastolic assessment in aortic regurgitation: a case report

BACKGROUND

Doppler transthoracic echocardiography is routinely performed to measure peak mitral inflow velocities in the assessment of left ventricular diastolic function. The limitations of echocardiography are well documented, but its accuracy in the measurement of transmitral peak velocity in the presence of aortic valve regurgitation has not yet been compared with four-dimensional flow cardiac magnetic resonance imaging. Four-dimensional flow cardiac magnetic resonance imaging offers time-resolved cross-sectional velocity information that can be used to investigate mitral inflow peak velocity. We present a case report demonstrating the potential superior capabilities of four-dimensional flow cardiac magnetic resonance imaging in accurately detecting mitral inflow velocities over Doppler echocardiography in patients with aortic regurgitation.

CASE PRESENTATION

A 67-year-old Caucasian female presented to our outpatient cardiology clinic with exertional dyspnea. Doppler transthoracic echocardiography identified moderate to severe aortic regurgitation. Mapping of mitral inflow peak velocities proved challenging with Doppler echocardiography. Additionally, four-dimensional flow cardiac magnetic resonance imaging with automated three-dimensional flow streamlines was performed, which allowed for more accurate detection of mitral inflow peak velocities.

CONCLUSIONS

Doppler echocardiography has a limited role in mitral inflow assessment where aortic regurgitation is present. In such cases, four-dimensional flow cardiac magnetic resonance imaging is an alternative imaging technique that may circumvent this issue and allow mitral inflow assessment.

Left Atrial Reservoir Strain-Based Left Ventricular Diastolic Function Grading and Incident Heart Failure in Hypertrophic Cardiomyopathy

BACKGROUND

The echocardiographic assessment of left ventricular (LV) diastolic dysfunction (LVDD) in patients with hypertrophic cardiomyopathy is complex and not well-established. We investigated whether the left atrial reservoir strain (LARS) could be used to categorize LVDD and whether this grading is predictive of heart failure (HF) events in hypertrophic cardiomyopathy.

METHODS

A total of 414 patients with hypertrophic cardiomyopathy (aged 58.3±12.8 years; 65.7% male) were categorized using LARS-defined LVDD (LARS-DD) grades: ≥35% (grade 0), ≥24% to <35%, ≥19% to <24%, and <19% (grade 3). Patients were followed for a median of 6.9 years to assess hospitalization for HF or HF-related death.

RESULTS

An increase in LARS-DD grade was associated with worse conventional echocardiographic parameters of LVDD, such as lower e', higher E/e' ratio, greater maximum tricuspid regurgitation velocity, and restrictive mitral inflow pattern. Higher LARS-DD grade was also associated with parameters reflecting increased LV filling pressure, such as greater LV wall thickness, greater extent of fibrosis, obstructive physiology, and decreased LV longitudinal strain. Furthermore, higher LARS-DD grade was associated with worse HF-free survival (log-rank P<0.001). Patients with LARS-DD grades 0, 1, 2, and 3 showed 10-year HF-free survival of 100%, 91.6%, 84.1%, and 67.5%, respectively. LARS-DD grade was an independent predictor of HF events after adjusting for clinical and echocardiographic variables (hazard ratio, 1.53 [95% CI, 1.03-2.28], per 1-grade increase). The LARS-DD grade also had incremental prognostic value for incident HF events over the traditional echocardiographic LVDD parameters and grading system. The prognostic value of advanced LARS-DD grade was consistent in sensitivity analyses and various patient subgroups.

CONCLUSIONS

LARS can be used as a simple single or supplemental index to categorize LV diastolic function and predict HF events in hypertrophic cardiomyopathy.

Improvement of the Accuracy in the Identification of Coronary Artery Disease Combining Heart Sound Features

Most researchers use features of diastolic murmurs to identify coronary artery disease. However, the diastolic murmurs of coronary artery disease are usually very weak and are easily contaminated by noise and valvular murmurs. Therefore, the diagnostic accuracy of coronary artery disease when only using diastolic murmurs is not well. An algorithm for improving the accuracy in the identification of coronary artery disease by combining the features of the first heart sound and diastolic murmurs was proposed. Firstly, a first heart sound feature extraction algorithm was used to identify coronary artery disease from noncoronary artery disease. Secondly, the Empirical Wavelet Transform algorithm was used to decompose the diastolic heart sound into three modes, and the spectral energy of each mode was calculated to distinguish coronary artery disease from noncoronary artery disease. Then, the features of the fist heart sound, the second diastolic spectral energy, and the parameter P3, which was used to discriminate the diastolic murmurs in coronary artery disease and in valvular disease, were combined together to improve the diagnostic accuracy of coronary artery disease. The comparison experiment results show that the accuracy of the proposed algorithm is superior to some state-of-the-art methods when they are used to diagnose coronary artery disease.

Review of Twenty-Six Volumes of History of Science and Technology in China

This article reviews twenty-six volumes of History of Science and Technology in China, a collaborative scholarly work published from 1998 to 2011. The review focuses on the volumes dealing with the history of technology: Mining and Metallurgy, Machinery, and Transportation. Clearly the series has impacted Chinese literature on the history of technology in China, being the first work to comprehensively and systematically study and expound the history of science and technology in ancient China from the perspective of Chinese scholars.

Noise Robust Detection of Fundamental Heart Sound using Parametric Mixture Gaussian and Dynamic Programming

In this work, we propose an unsupervised algorithm for fundamental heart sound detection. We propose to detect the heart sound candidates using the stationary wavelet transforms and group delay. We further propose an objective function to select the candidates. The objective function has two parts. We model the energy contour of S1/S2 sound using the Gaussian mixture function (GMF). The goodness of fit for the GMF is used as the first part of the objective function. The second part of the objective function captures the consistency of the heart sounds' relative location. We solve the objective function efficiently using dynamic programming. We evaluate the algorithm on Michigan HeartSound and Murmur database. We also assess the algorithm's performance using the three different additive noises- white Gaussian noise (AWGN), Student-t noise, and impulsive noise. The experiments demonstrate that the proposed method performs better than baseline in both clean and noisy conditions. We found that the proposed method is robust in the case of AWGN noise and student-t distribution noise. But its performance reduces in case of impulsive noise.

Identification of Heart Sounds with an Interpretable Evolving Fuzzy Neural Network

Heart problems are responsible for the majority of deaths worldwide. The use of intelligent techniques to assist in the identification of existing patterns in these diseases can facilitate treatments and decision making in the field of medicine. This work aims to extract knowledge from a dataset based on heart noise behaviors in order to determine whether heart murmur predilection exists or not in the analyzed patients. A heart murmur can be pathological due to defects in the heart, so the use of an evolving hybrid technique can assist in detecting this comorbidity team, and at the same time, extract knowledge through fuzzy linguistic rules, facilitating the understanding of the nature of the evaluated data. Heart disease detection tests were performed to compare the proposed hybrid model's performance with state of the art for the subject. The results obtained (90.75% accuracy) prove that in addition to great assertiveness in detecting heart murmurs, the evolving hybrid model could be concomitant with the extraction of knowledge from data submitted to an intelligent approach.

Deep Neural Networks for the Recognition and Classification of Heart Murmurs Using Neuromorphic Auditory Sensors

Auscultation is one of the most used techniques for detecting cardiovascular diseases, which is one of the main causes of death in the world. Heart murmurs are the most common abnormal finding when a patient visits the physician for auscultation. These heart sounds can either be innocent, which are harmless, or abnormal, which may be a sign of a more serious heart condition. However, the accuracy rate of primary care physicians and expert cardiologists when auscultating is not good enough to avoid most of both type-I (healthy patients are sent for echocardiogram) and type-II (pathological patients are sent home without medication or treatment) errors made. In this paper, the authors present a novel convolutional neural network based tool for classifying between healthy people and pathological patients using a neuromorphic auditory sensor for FPGA that is able to decompose the audio into frequency bands in real time. For this purpose, different networks have been trained with the heart murmur information contained in heart sound recordings obtained from nine different heart sound databases sourced from multiple research groups. These samples are segmented and preprocessed using the neuromorphic auditory sensor to decompose their audio information into frequency bands and, after that, sonogram images with the same size are generated. These images have been used to train and test different convolutional neural network architectures. The best results have been obtained with a modified version of the AlexNet model, achieving 97% accuracy (specificity: 95.12%, sensitivity: 93.20%, PhysioNet/CinC Challenge 2016 score: 0.9416). This tool could aid cardiologists and primary care physicians in the auscultation process, improving the decision making task and reducing type-I and type-II errors.

Analysis of phonocardiogram signals through proactive denoising using novel self-discriminant learner

Phonocardiogram (PCG) records heart sound and murmurs, which contains significant information of cardiac health. Analysis of PCG signal has the potential to detect abnormal cardiac condition. However, the presence of noise and motion artifacts in PCG hinders the accuracy of clinical event detection. Thus, noise detection and elimination are crucial to ensure accurate clinical analysis. In this paper, we present a robust denoising technique, Proclean that precisely detects the noisy PCG signal through pattern recognition, and statistical learning. We propose a novel self-discriminant learner that ensures to obtain distinct feature set to distinguish clean and noisy PCG signals without human-in-loop. We demonstrate that our proposed denoising leads to higher accuracy in subsequent clinical analytics for medical investigation. Our extensive experimentations with publicly available MIT-Physionet datasets show that we achieve more than 85% accuracy for noisy PCG signal detection. Further, we establish that physiological abnormality detection improves by more than 20%, when our proposed denoising mechanism is applied.

[Unusual diagnosis of an intrathoracic tumor, cavernosum lymphangioma. Case report]

BACKGROUND

Thoracic lymphangioma is a rare benign disease representing only 0.7-4.5% of all mediastinal tumors. Its etiology is currently unknown. Most are asymptomatic at first, and the condition is common in the pediatric age. We present a case to document this rare disease and describe the literature.

CLINICAL CASE

We present the case of a 5-year-old female without clinically significant medical history. The patient attended a routine physician visit where a heart murmur was discovered. A diagnostic protocol was initiated, finding a mass on chest x-rays, apparently with an intrathoracic localization. Chest computed tomography confirms a tumor of 13 × 11 cm localized in the anterior mediastinum. Laboratory studies were within normal parameters. Complete surgical resection was decided upon and histopathological diagnosis of cavernosum lymphangioma is confirmed. The patient experienced an adequate evolution without evidence of relapse at this timeConclusion: Characteristics of the case shown are consistent with those reported in the literature. Diagnostic management as well as the surgical plan was successful without presenting morbidity so far.

Application of Laser Doppler Vibrometery for human heart auscultation

In this study the potential of a Laser Doppler Vibrometer (LDV) was tested as a non-contact sensor for the classification of heart sounds. Of the twenty participants recorded using the LDV, five presented with Aortic Stenosis (AS), three were healthy and twelve presented with other pathologies. The recorded heart sounds were denoised and segmented using a combination of the Electrocardiogram (ECG) data and the complexity of the signal. Frequency domain features were extracted from the segmented heart sound cycles and used to train a K-nearest neighbor classifier. Due to the small number of participants, the classifier could not be trained to differentiate between normal and abnormal participants, but could successfully distinguish between participants who presented with AS and those who did not. A sensitivity of 80 % and a specificity of 100 % were achieved a test dataset.

Learning during simulation training is prone to retroactive interference

CONTEXT

Retroactive interference occurs when newly acquired information inhibits recall of previously learned information. This has been shown to influence recall of sounds, tastes and word associations, and is typically seen when learners receive training on one area of content and are then exposed to new content before being evaluated on the original content. Thus far, retroactive interference has received little attention in medical education and has not been studied during simulation training. Our objective was to evaluate whether retroactive interference occurs during simulation training.

METHODS

We randomised 167 Year 1 medical students to one of two training protocols. After training on a cardiac murmur, participants were tested either on the same cardiac murmur followed by a novel murmur (the non-interference protocol), or on the novel murmur followed by the training murmur (the interference protocol). We evaluated performance on both murmurs at 1 hour and 6 weeks post-training.

RESULTS

We found a significant interaction between training protocol and diagnostic performance on training versus novel murmurs at both testing time-points. Students in the non-interference protocol had increased odds of achieving success on the training murmur relative to the novel murmur at 1 hour (odds ratio [OR] 4.96; p < 0.001) and at 6 weeks (OR 4.23; p = 0.001) after training. By comparison, students in the interference protocol did not demonstrate improved performance on the training murmur relative to the novel murmur at either evaluation (1 hour post-training: OR 0.56 [p = 0.08]; 6 weeks post-training: OR 0.66 [p = 0.23]).

CONCLUSIONS

Consistent with the theory of retroactive interference, students who encountered a novel murmur between training and evaluation on the murmur on which they had been trained showed no improvement in diagnostic performance following simulation training. These findings should serve to warn educators to consider retroactive interference when designing simulation training sessions.

Severity of aortic stenosis assessed by carotid pulse recordings and phonocardiography

The external carotid pulse, the PCG, and the ECG were studied in 26 adult patients with valvular aortic stenosis whose systolic peak pressure gradients ranged from 18 to 165 mmHg. A significant correlation was found between the rapidity of the pulse upstroke, as measured by the T-time, and the location of the peak of the systolic murmur during ventricular ejection, on the one hand, and the gradient, on the other. The left ventricular ejection time (LVET) related directly and the pre-ejection period (PEP) indirectly with the gradient. There was a signficant inverse relationship between the PEP/LVET quotient and the pressure gradient but this quotient did not classify the patients according to the severity of the stenosis as well as the T-time and the location of the peak of murmur. When a combination of the T-time, the PEP/LVET, and the location of the peak of the murmur was used in each patient, a good discrimination between the patients was achieved. When the pressure gradient was above 50 mmHg, at lease one of the measurements was abnormal and when it exceeded 100 mmHg, at least two measurements were abnormal. The study further showed that it is possible to separate patients with valvular aortic stenosis from those with hypertrophic obstructive cardiomyopathy lidiopathic hypertrophic subaortic stenosis) or mitral insufficiency on the basis of carotid pulse tracings and PCGs.

Improvement in medical consultation responses with a structured request form

Physicians often do not provide adequate information regarding patients' medical conditions when presented with consultation requests (CR) generated by dental students and their instructors about the students' patients. We hypothesized that a structured CR form, which requests specific information by providing a checklist and/or closed-ended questions for physicians to answer, would lead to better communication and improved responses. We also hypothesized that providing in-service education to clinical faculty on the conditions that require and don't require CRs would reduce the number of unwarranted CRs sent to physicians. We assessed the responses obtained with the new form and compared them to findings over a similar period using our older, unstructured CR forms. We also evaluated the numbers of CRs written unnecessarily during both time periods. Improvements in the appropriateness of information provided by physicians were noted with the new CR forms for diabetes mellitus, hypertension, heart murmur, and anticoagulant therapy. The number of CRs written for conditions that did not need a consultation was approximately the same after provision of instruction as before. We conclude that structured CR forms improve the flow of information between dentists and physicians and should enhance student knowledge and skills in soliciting relevant information. Greater efforts must be taken to inform clinical faculty about the indications for CRs.

[The art of cardiac auscultation]

Auscultation of the heart should be performed systematically on the five standard auscultation points. During this procedure every sound must be exactly documented. Furthermore, splitting of the heart sounds and clicks, if present, must be noted. Frequently the interpretation of the various sounds is difficult. Clinically significant sounds and therefore requiring further clarification must be filtered out from the many innocent heart murmurs. This is possible only with time, patience and constant practice.

[Nutritional status of adopted Chinese girls in Spain]

INTRODUCTION

Given the increasing number of adoptions from China in countries such as Spain, a study was designed to know and assess the nutritional profile at arrival and its likely implication in global health status, growth, and development of adopted Chinese girls.

PATIENTS AND METHODS

Eighty-five Chinese girls adopted in Spain during the 2002-2003 period and ages ranging 7-33 months of life were studied at the Social Pediatrics Unit of the "Niño Jesús" Hospital, Madrid. Datas regarding institution of origin, nutritional parameters (anthropometrical and biochemical), presence of associated diseases, and developmental retardations (psychomotor/bone age) were gathered.

RESULTS

Waterlow's nutritional index showed a malnourishment rate of 11% based on Chinese reference tables, as compared to 58% based on Spanish tables, of which 82% was acute malnourishment. When comparing the efficacy of both nutritional assessment methods proposed by Waterlow and Gomez, there were no differences in detection of malnourishment in spite of the fact that the latter author gives priority to the weight/age index as a nutritional indicator at ages lower than 2 years. Eighteen percent of the girls were considered at (height/age < p10) of suffering chronic malnourishment, but this was only confirmed in 67% of the group according to Waterlow's criteria. Among assessed plasma parameters, decreased prealbumin, lymphocytes, iron, and transferrin stand out. The predominant pathological findings were thalassemia, dermatitis, psychomotor retardation, and ferropenic anemia.

CONCLUSIONS

These results make us believe in a possible improvement in the conditions at Chinese orphanages. The low age at the time of adoption may justify the low incidence of chronic nutritional deficiencies. As a whole, anthropometrical / nutritional impairments found may be related with the consequences of carelessness and vulnerability of the adoption process. In any case, early diagnosis and implementation of appropriate therapy as soon as possible, as it is being done, is essential to provide appropriate growth and development of these girls.