Roadmap on computational methods in optical imaging and holography [invited].

Computational methods have been established as cornerstones in optical imaging and holography in recent years. Every year, the dependence of optical imaging and holography on computational methods is increasing significantly to the extent that optical methods and components are being completely and efficiently replaced with computational methods at low cost. This roadmap reviews the current scenario in four major areas namely incoherent digital holography, quantitative phase imaging, imaging through scattering layers, and super-resolution imaging. In addition to registering the perspectives of the modern-day architects of the above research areas, the roadmap also reports some of the latest studies on the topic. Computational codes and pseudocodes are presented for computational methods in a plug-and-play fashion for readers to not only read and understand but also practice the latest algorithms with their data. We believe that this roadmap will be a valuable tool for analyzing the current trends in computational methods to predict and prepare the future of computational methods in optical imaging and holography. Supplementary Information: The online version contains supplementary material available at 10.1007/s00340-024-08280-3.

Assessment of Preappointment Parental Counseling on Dental Fear and Anxiety in Children in Pedodontic Dental Operatory: A Randomized Controlled Trial.

Background: Dental fear and anxiety are important issues in the practice of pediatric dentistry because they interfere with both the provision and receipt of dental care in children and adolescents. Behavior guidance is a dynamic part of child management. It starts from the preappointment level, where a negative attitude of the mother will be trained to become positive for improved child behavior in the pediatric dental clinic. The use of anticipatory guidance (AG) as parental counseling, where the information on what the parents should follow before their child's dental appointment was provided to the mothers. Aim: To assess the effect of preappointment parental counseling on dental fear and anxiety in children. Materials and methods: The study was a randomized, parallel-group, active-controlled trial, wherein the dyad of mother and child was randomly divided into two groups: (1) the test group and (2) the control group. At baseline, fear and anxiety assessment was done using fear and anxiety assessment scales and physiological parameters in both groups. Dental fear and anxiety were assessed using the children fear survey schedule dental subscale, Venham pictorial test in children and state-trait anxiety subscale in mothers. Parental counseling instructions were given verbally, in written format and by videos only in the test group on the same day of the initial appointment. The same subjects in both groups were checked for fear and anxiety scales and physiological parameters after 6 months from the first appointment. The effectiveness of parental counseling on dental fear and anxiety was correlated at the end of the study. Statistical analysis: The mean dental fear and anxiety scores between the test and control groups at baseline and at 6 months were compared using the Chi-squared test. Chi-squared test was used to compare the dental fear and anxiety in children and mothers in the study and control groups. Spearman's rank correlation test was used to assess the relationship between Children's Fear Survey Schedule-Dental Subscale (CFSS-DS), Venham Picture Test (VPT), state-trait anxiety inventory (STAI) scores, and clinical parameters in the study and control group of both populations. Results: The results showed that there was a significant improvement in the dental fear and anxiety levels in the dyads of mother and child postcounseling. The control group scores did not show any significant change. Conclusion: Preappointment parental counseling clarified and guided parents about the child's fear and anxiety and was effective in alleviating the dental fear and anxiety among parents and children attending pediatric dental clinics. How to cite this article: R R, Sathyaprasad S, S N, et al. Assessment of Preappointment Parental Counseling on Dental Fear and Anxiety in Children in Pedodontic Dental Operatory: A Randomized Controlled Trial. Int J Clin Pediatr Dent 2024;17(3):346-351.

Multimodal Imaging in Mycobacterium Chimaera Cardiovascular Infections: The Mayo Clinic Experience.

Objective: To review the salient features of multimodality cardiovascular imaging in patients with disseminated Mycobacterium chimaera (MC) infections after exposure to contaminated heater-cooler units during cardiopulmonary bypass. Patients and Methods: Twelve patients with confirmed MC infection were retrospectively identified after a review from January 1, 2010, to April 30, 2021. The electronic medical records were examined with a focus on transthoracic echocardiography, transesophageal echocardiography, cardiac computed tomography (CT), cardiac magnetic resonance imaging, and positron emission tomography-CT. Results: Three (27.3%) patients had diagnostic findings of endocarditis on transthoracic echocardiography, with most patients having nonspecific abnormalities including elevated prosthetic valve gradients or prosthetic leaflet thickening. Transesophageal echocardiography identified 4 (36.7%) patients with vegetations and 3 (27.3%) with aortic root abscess or pseudoaneurysm, with more common findings such as mild aortic root or prosthetic leaflet thickening. Six (50%) patients underwent cardiac CT imaging, which found aortic root pseudoaneurysms or abscesses, prosthetic ring dehiscence, and leaflet thickening. Three (25%) patients underwent cardiac magnetic resonance imaging demonstrating prosthetic valve vegetations, leaflet thickening, and abnormal myocardial delayed enhancement in a noncoronary distribution, suggesting myocarditis. Ten (83%) patients underwent positron emission tomography-CT, 4 (40%) had an abnormal fluorodeoxyglucose uptake around the cardiac prosthetic material, and 7 (70%) had a fluorodeoxyglucose uptake in other organs, suggesting concomitant multiorgan involvement. Conclusion: Multimodality cardiovascular imaging is central to the management of patients with disseminated MC and can help establish a preliminary diagnosis while awaiting confirmatory microbiological data, potentially reducing the time to diagnosis. Imaging findings are subtle and atypical, not always meeting classically modified Duke's criteria for infectious endocarditis. Clinicians should have a high index of suspicion for the disease and a low threshold for repeat imaging when initial testing is equivocal.

Racial, ethnic and sex disparity in acute heart failure patients with COVID-19: A nationwide analysis.

Background: Patients with acute heart failure (AHF) exacerbation are susceptible to complications in the setting of COVID-19 infection. Data regarding the racial/ethnic and sex disparities in patients with AHF and COVID-19 remains limited. Objective: We aim to evaluate the impact of race, ethnicity, and sex on the in-hospital outcomes of AHF with COVID-19 infection using the data from the National Inpatient Sample (NIS). Methods: We extracted data from the NIS (2020) by using ICD-10-CM to identify all hospitalizations with a diagnosis of AHF and COVID-19 in the year 2020. The associations between sex, race/ethnicity, and outcomes were examined using a multivariable logistic regression model. Results: We identified a total of 158,530 weighted AHF hospitalizations with COVID-19 infection in 2020. The majority were White (63.9 %), 23.3 % were Black race, and 12.8 % were of Hispanic ethnicity, mostly males (n = 84,870 [53.5 %]). After adjustment, the odds of in-hospital mortality were lowest in White females (aOR 0.83, [0.78-0.98]) and highest in Hispanic males (aOR 1.27 [1.13-1.42]) compared with White males. Overall, the odds of cardiac arrest (aOR 1.54 [1.27-1.85]) and AKI (aOR 1.36 [1.26-1.47] were higher, while odds for procedural interventions such as PCI (aOR 0.23 [0.10-0.55]), and placement on a ventilator (aOR 0.85 [0.75-0.97]) were lower among Black males in comparison to White males. Conclusion: Male sex was associated with a higher risk of in-hospital mortality in white and black racial groups, while no such association was noted in the Hispanic group. Hispanic males had the highest odds of death compared with White males.

Bridging ECG learning with emerging technologies: Advancing clinical excellence.

As ECG technology rapidly evolves to improve patient care, accurate ECG interpretation will continue to be foundational for maintaining high clinical standards. Recent studies have exposed significant educational gaps, with many healthcare professionals lacking sufficient training and proficiency. Furthermore, integrating new software and hardware ECG technologies poses challenges about potential knowledge and skill erosion. This underscores the need for clinicians who are adept at integrating clinical expertise with technological proficiency. It also highlights the need for innovative solutions to enhance ECG interpretation among healthcare professionals in this rapidly evolving environment. This work explores the importance of aligning ECG education with technological advancements and proposes how this synergy could advance patient care in the future.

Acute and Complicated Inflammatory Pericarditis: A Guide to Contemporary Practice.

Inflammatory disease of the pericardium represents a relatively common presentation, especially among the young. For the most part, inflammatory pericardial disease can be expeditiously and effectively managed without significant sequelae. However, some individuals present with severe and recurrent illness, representing significant therapeutic challenges. During the past decade, there have been great strides made in developing an evidence-based approach to management of inflammatory pericardial disease, the result of which has been the development of (1) a systematic, protocoled approach to initial care; (2) targeted therapeutics; and (3) specialized, collaborative, and integrated care pathways. Herein we present a review of the current state of the art as it pertains to the diagnostic evaluation and therapeutic considerations in inflammatory pericardial disease with a focus on acute and complicated pericarditis.

Patients Aged 90 Years and Above With Acute Coronary Syndrome in the Cardiac Intensive Care Unit: Management and Outcomes.

Limited data exist regarding outcomes after coronary angiography (CAG) and percutaneous coronary intervention (PCI) in patients aged ≥90 years admitted to the cardiac intensive care unit (CICU) with acute coronary syndrome (ACS). We studied sequential CICU patients ≥90 years admitted with ACS from 2007 to 2018. Three therapeutic approaches were defined: (1) No CAG; (2) CAG without PCI (CAG/No PCI); and (3) CAG with PCI (CAG/PCI). In-hospital mortality was evaluated using multivariable logistic regression. All-cause 1-year mortality was evaluated using Kaplan-Meier and multivariable Cox proportional hazards analysis. The study included 239 patients with a median age of 92 (range 90 to 100) years (57% females; 45% ST-elevation myocardial infarction; 8% cardiac arrest; 16% shock). The No CAG group had higher Day 1 Sequential Organ Failure Assessment scores, more co-morbidities, worse kidney function, and fewer ST-elevation myocardial infarctions. In-hospital mortality was 20.8% overall and did not differ between the No CAG (n = 103; 21.4%), CAG/No PCI (n = 47; 21.3%), and CAG/PCI (n = 90; 20.0%) groups, before or after adjustment. Overall 1-year mortality was 52.5% and did not differ between groups before or after adjustment. Median survival was 6.9 months overall and 41.2% of hospital survivors died within 1 year of CICU admission. CICU patients aged ≥90 years with ACS have a substantial burden of illness with high in-hospital and 1-year mortality that was not lower in those who underwent CAG or PCI. These results suggest that careful patient selection for invasive coronary procedures is essential in this vulnerable population.

Thoracic Aortic Aneurysmal Disease: Comprehensive Recommendations for the Primary Care Physician.

Thoracic aortic aneurysm (TAA) is a commonly encountered disease that is defined as aortic dilation with an increase in diameter of at least 50% greater than the expected age- and sex-adjusted size. Thoracic aortic aneurysms are described by their size, location, morphology, and cause. Primary care clinicians and other noncardiologists are often the first point of contact for patients with TAA. This review is intended to provide them with basic information on the differential diagnosis, diagnostic evaluation, and medical and surgical management of TAAs. Management decisions depend on having as precise a diagnosis as possible. Fortunately, this can often be achieved with a stepwise diagnostic approach that incorporates imaging and targeted genetic testing. Our review includes recommendations. In this review, we discuss these issues at a basic level and include recommendations for patients considering pregnancy.

EDUCATE: An international, randomized controlled trial for teaching electrocardiography.

INTRODUCTION: Despite the critical role of electrocardiograms (ECGs) in patient care, evident gaps exist in ECG interpretation competency among healthcare professionals across various medical disciplines and training levels. Currently, no practical, evidence-based, and easily accessible ECG learning solution is available for healthcare professionals. The aim of this study was to assess the effectiveness of web-based, learner-directed interventions in improving ECG interpretation skills in a diverse group of healthcare professionals. METHODS: In an international, prospective, randomized controlled trial, 1206 healthcare professionals from various disciplines and training levels were enrolled. They underwent a pre-intervention test featuring 30 12-lead ECGs with common urgent and non-urgent findings. Participants were randomly assigned to four groups: (i) practice ECG interpretation question bank (question bank), (ii) lecture-based learning resource (lectures), (iii) hybrid question- and lecture-based learning resource (hybrid), or (iv) no ECG learning resources (control). After four months, a post-intervention test was administered. The primary outcome was the overall change in ECG interpretation performance, with secondary outcomes including changes in interpretation time, self-reported confidence, and accuracy for specific ECG findings. Both unadjusted and adjusted scores were used for performance assessment. RESULTS: Among 1206 participants, 863 (72 %) completed the trial. Following the intervention, the question bank, lectures, and hybrid intervention groups each exhibited significant improvements, with average unadjusted score increases of 11.4 % (95 % CI, 9.1 to 13.7; P<0.01), 9.8 % (95 % CI, 7.8 to 11.9; P<0.01), and 11.0 % (95 % CI, 9.2 to 12.9; P<0.01), respectively. In contrast, the control group demonstrated a non-significant improvement of 0.8 % (95 % CI, -1.2 to 2.8; P=0.54). While no differences were observed among intervention groups, all outperformed the control group significantly (P<0.01). Intervention groups also excelled in adjusted scores, confidence, and proficiency for specific ECG findings. CONCLUSION: Web-based, self-directed interventions markedly enhanced ECG interpretation skills across a diverse range of healthcare professionals, providing an accessible and evidence-based solution.

Outcomes of transcatheter aortic valve replacement in patients with and without amyloidosis: A nationwide analysis from the United States.

BACKGROUND: Amyloidosis is a common comorbidity in elderly patients with aortic stenosis (AS) referred for transcatheter aortic valve replacement (TAVR). This study aims to assess the impact of amyloidosis on the clinical outcomes of TAVR. METHODS: This is a retrospective study of the National Inpatient Sample database that identified adult patients (≥18 years) with AS hospitalized for TAVR from 2016 through 2020 to compare outcomes in those with versus without amyloidosis. Our primary outcome was in-hospital mortality. Secondary outcomes included procedural complications, hospital length of stay (LOS), and total costs. TAVR trends in both cohorts were also evaluated. RESULTS: The total cohort included 304,710 patients with AS undergoing TAVR, of whom 410 had amyloidosis. Over the study period, TAVR trends increased significantly in patients with and without amyloidosis (both ptrend < 0.01). Patients with amyloidosis were more likely to be older males with atrial fibrillation/flutter, congestive heart failure, renal disease, and dementia compared to non-amyloidosis patients. After adjustment for baseline characteristics, patients with amyloidosis had similar odds of in-hospital mortality (adjusted odds ratio [aOR] 1.66, 95 % confidence interval [CI] 0.34-3.63), heart block (aOR 1.33, 95 % CI 0.84-2.10), permanent pacemaker insertion (aOR 0.67, 95 % CI 0.27-1.66), stroke (aOR 0.90, 95 % CI 0.32-3.13), acute kidney injury, major bleeding, blood transfusion, vascular complications, in addition to similar LOS (p = 0.21) and total costs (p = 0.18) compared to patients without amyloidosis. CONCLUSION: In patients with AS undergoing TAVR, comorbid amyloidosis is associated with similar in-hospital mortality and procedural complications compared to patients without amyloidosis.

Evaluation of microplastic pollution and risk assessment in a tropical monsoonal estuary, with special emphasis on contamination in jellyfish.

Estuaries, which serve as vital links between land and coastal ecosystems, play a significant part in facilitating the transfer of plastic waste from the land to the ocean. In this research, we examined the prevalence, characteristics, and ecological risks of microplastics (MPs) in the extensively urbanized Cochin Estuarine System (CES), India. Additionally, it represents one of the initial evidence-based examinations of MPs ingestion by jellyfish in Indian waters, focusing on Acromitus flagellatus, Blackfordia virginica, and Pleurobrachia pileus species. The abundance of MPs found in the surface water of the Cochin Estuarine System (CES) varied between 14.44 ± 9 to 30 ± 15.94 MP/m3, with an average of 21.6 ± 11 MP/m3. In both surface waters and jellyfish from the Cochin Estuarine System (CES), fibers were the most prevalent type of MPs, with polyethylene (PE), polypropylene (PP), and polyamide (PA) being the most common polymer varieties. To evaluate the current levels of MPs and their effect on the CES, the Pollution Load Index (PLI), Potential Ecological Risk Index (PERI), and Polymeric Risk Index (H) were utilized. The high PLIestuary values (20.33), high Hestuary values (234.02), and extreme PERIestuary value (1646.06) indicate that the CES is facing an extreme ecological risk. Among the 280 jellyfish individuals examined, 118 (42.14%) were recognized to contain MPs with an average of 1.54 ± 2.68 MPs/individual. Pearson bivariate analysis revealed a significant correlation between the jellyfish bell size and number of plastics per individual. Comparison between jellyfish species revealed, the majority (66%) of the MPs identified in jellyfish were from A. flagellatus and 44 among the 50 jellyfish examined (88%) had MPs. These findings suggest that A. flagellatus may be a potential sink for MPs and may be utilized to be a bioindicator for monitoring MPs contamination in estuarine systems, aiding in future plastic pollution mitigation efforts.

Noninvasive Hemodynamic Characterization of Shock and Preshock Using Echocardiography in Cardiac Intensive Care Unit Patients.

BACKGROUND: Shock and preshock are defined on the basis of the presence of hypotension, hypoperfusion, or both. We sought to determine the hemodynamic underpinnings of shock and preshock noninvasively using transthoracic echocardiography (TTE). METHODS AND RESULTS: We included Mayo Clinic cardiac intensive care unit patients from 2007 to 2015 with TTE within 1 day of admission. Hypotension and hypoperfusion at the time of cardiac intensive care unit admission were used to define 4 groups. TTE findings were evaluated across these groups, and in-hospital mortality was evaluated according to TTE findings in each group. We included 5375 patients with a median age of 69.2 years (36.8% women). The median left ventricular ejection fraction was 50%. Groups based on hypotension and hypoperfusion were assigned as follows: no hypotension or hypoperfusion, 59.7%; isolated hypotension, 15.3%; isolated hypoperfusion, 16.4%; and both hypotension and hypoperfusion, 8.7%. Most TTE variables of interest varied across these groups, with worse biventricular function, lower forward flow, and higher filling pressures as the degree of hemodynamic compromise increased. In-hospital mortality occurred in 8.2%, and inpatient deaths had more TTE parameter abnormalities. In-hospital mortality increased with the degree of hemodynamic compromise, and a marked gradient in in-hospital mortality was observed when the clinical classification of shock and preshock was combined with TTE findings reflecting worse biventricular function, lower forward flow, or higher filling pressures. CONCLUSIONS: Substantial differences in cardiac function are observed between cardiac intensive care unit patients with preshock and shock using TTE, and the combination of the clinical and TTE hemodynamic assessment provides robust mortality risk stratification.

CELLULAR RNA INTERACTS WITH MAVS TO PROMOTE ANTIVIRAL SIGNALING.

Immune signaling needs to be well-regulated to promote clearance of pathogens, while preventing aberrant inflammation. Interferons (IFNs) and antiviral genes are activated by the detection of viral RNA by RIG-I-like receptors (RLRs). Signal transduction downstream of RLRs proceeds through a multi-protein complex organized around the central adaptor protein MAVS. Recent work has shown that protein complex function can be modulated by RNA molecules providing allosteric regulation or acting as molecular guides or scaffolds. Thus, we hypothesized that RNA plays a role in organizing MAVS signaling platforms. Here, we show that MAVS, through its central intrinsically disordered domain, directly interacts with the 3' untranslated regions of cellular mRNAs. Importantly, elimination of RNA by RNase treatment disrupts the MAVS signalosome, including newly identified regulators of RLR signaling, and inhibits phosphorylation of the transcription factor IRF3. This supports the hypothesis that RNA molecules scaffold proteins in the MAVS signalosome to induce IFNs. Together, this work uncovers a function for cellular RNA in promoting signaling through MAVS and highlights a generalizable principle of RNA regulatory control of cytoplasmic immune signaling complexes.

Land use drives large CH4 fluxes from a highly urbanized Indian estuary.

There is growing awareness of the need to better constrain the contribution of atmospheric methane (CH4) fluxes from urbanized estuaries due to the high global warming potential of CH4 and the accelerating growth of urban expansion. This study undertook seasonal sampling campaigns to understand the impact of urbanization on atmospheric CH4 fluxes and their drivers in a large, tropical estuary in India. Overall, the study found that the Cochin estuary emitted large amounts of CH4 (398.8 ± 141.6 µmolm-2d-1) to the atmosphere with CH4 hotspots reaching up to 939.7 µmolm-2d-1 were identified. The strongest drivers of CH4 dynamics in different anthropogenically impacted zones were traced. The source of organic matter for CH4 production was revealed to be terrestrial C3 plants, autochthonous production, marine phytoplankton, and sewage inputs. The study suggests that monsoonal urbanized tropical estuaries may be an important but under-recognized element of the global CH4 budget.

Patterns and variability in the microplastic contamination along the southwest coast of India with emphasis on submarine groundwater discharge sites.

Beach sediments of the southwest coast of India were analysed to estimate the microplastic contamination with emphasis on the submarine groundwater discharge (SGD) zones. Both SGD and non-SGD sites were assessed for abundance, morphotype and polymer type of microplastics. Microplastic load was 230.429 ± 62.87 particles per 100 g. Fibre, mainly blue, was the abundant morphotype, followed by fragment, foam and film. The polymer types were POLYETHYLENE (PE) (30.77 %), POLYPROPYLENE (PP) (26.92 %), POLYAMIDE (PA) (19.23 %), POLYSTYRENE (PS) (11.54 %), ETHYLENE VINYL ACETATE (EVA) (7.692 %) and POLYVINYL CHLORIDE (PVC) (3.846 %). The SGD zones exhibited higher microplastic contamination with statistically significant variations from non SGD sites. The study accounts the levels of microplastic contamination along the southwest coast of India, a major fishery zone. The higher abundance of microplastic in the SGD zones indicates the significance of subterranean groundwater through flow as a pathway of anthropogenic contaminants towards marine ecosystems.

Multimodality Imaging in Differentiating Constrictive Pericarditis From Restrictive Cardiomyopathy: A Comprehensive Overview for Clinicians and Imagers.

In the evaluation of heart failure, 2 differential diagnostic considerations include constrictive pericarditis and restrictive cardiomyopathy. The often outwardly similar clinical presentation of these 2 pathologic entities routinely renders their clinical distinction difficult. Consequently, initial assessment requires a keen understanding of their separate pathophysiology, epidemiology, and hemodynamic effects. Following a detailed clinical evaluation, further assessment initially rests on comprehensive echocardiographic investigation, including detailed Doppler evaluation. With the combination of mitral inflow characterization, tissue Doppler assessment, and hepatic vein interrogation, initial differentiation of constrictive pericarditis and restrictive cardiomyopathy is often possible with high sensitivity and specificity. In conjunction with a compatible clinical presentation, successful differentiation enables both an accurate diagnosis and subsequent targeted management. In certain cases, however, the diagnosis remains unclear despite echocardiographic assessment, and additional evaluation is required. With advances in noninvasive tools, such evaluation can often continue in a stepwise, algorithmic fashion noninvasively, including both cross-sectional and nuclear imaging. Should this additional evaluation itself prove insufficient, invasive assessment with appropriate expertise may ultimately be necessary.

Predictors of ECG Interpretation Proficiency in Healthcare Professionals.

Accurate ECG interpretation is vital, but variations in skills exist among healthcare professionals. This study aims to identify factors contributing to ECG interpretation proficiency. Survey data and ECG interpretation test scores from participants in the EDUCATE Trial were analyzed to identify predictors of performance for 30 sequential 12-lead ECGs. Nonmodifiable factors (being a physician, clinical experience, patient care impact) and modifiable factors (weekly interpretation volume, training hours, expert supervision frequency) were analyzed. Bivariate and multivariate analyses were used to generate a Comprehensive Model (incorporating all factors) and Actionable Model (incorporating modifiable factors only). Among 1206 participants analyzed, there were 72 (6.0%) primary care physicians, 146 (12.1%) cardiology fellows-in-training, 353 (29.3%) resident physicians, 182 (15.1%) medical students, 84 (7.0%) advanced practice providers, 120 (9.9%) nurses, and 249 (20.7%) allied health professionals. Among them, 571 (47.3%) were physicians and 453 (37.6%) were nonphysicians. The average test score was 56.4% ± 17.2%. Bivariate analysis demonstrated significant associations between test scores and >10 weekly ECG interpretations, being a physician, >5 training hours, patient care impact, and expert supervision but not clinical experience. In the Comprehensive Model, independent associations were found with weekly interpretation volume (9.9 score increase; 95% CI, 7.9-11.8; P < 0.001), being a physician (9.0 score increase; 95% CI, 7.2-10.8; P < 0.001), and training hours (5.7 score increase; 95% CI, 3.7-7.6; P < 0.001). In the Actionable Model, scores were independently associated with weekly interpretation volume (12.0 score increase; 95% CI, 10.0-14.0; P < 0.001) and training hours (4.7 score increase; 95% CI, 2.6-6.7; P < 0.001). The Comprehensive and Actionable Models explained 18.7% and 12.3% of the variance in test scores, respectively. Predictors of ECG interpretation proficiency include nonmodifiable factors like physician status and modifiable factors such as training hours and weekly ECG interpretation volume.