Heterogeneity of Coronary Vascular Function and Myocardial Oxygenation in Women with Angina and Non-obstructive Coronary Artery Disease.

AIMS: Women with angina and non-obstructive coronary artery disease (ANOCA) have a heightened risk for cardiovascular events, and the pathophysiology for ischemic symptoms may be related to alterations in microvascular structure and function. We examined the use of breathing-enhanced oxygenation-sensitive cardiac magnetic resonance imaging (OS-CMR) using vasoactive breathing maneuvers to assess myocardial oxygenation in women with ANOCA. METHODS AND RESULTS: We recruited women (aged 40-65 years) from two sites in Canada who presented to healthcare with persistent retrosternal chest pain and found to have ANOCA, or without a history of cardiovascular disease. All participants were scanned using a clinical 3T MRI scanner, OS-CMR images were acquired over a breath hold following paced hyperventilation to measure global and regional measurements of heterogeneity.Fifty-four women with ANOCA (age: 55 +/- 6.2 years) and 48 healthy controls (age: (51.2+/- 4.8 years) were recruited. There was no significant difference in volume, function, mass, or global myocardial oxygenation between the two groups (mean % Δ in SI: 4.9 (+/- 7.3) vs. 4.5 (+/- 10.1), p = 0.82). Women with ANOCA had higher regional variations in myocardial oxygenation in circumferential (median % Δ in SI: 5.1 (2.0-7.6) vs. 2.2 (1.4-3.5), p = 0.0004) and longitudinal directions (median % Δ in SI: 11.4 (5.4-16.7) vs. 6.0 (3.0-7.0), p = 0.001), which remained present in a multivariate model. CONCLUSION: Heterogeneous myocardial oxygenation may explain ischemic symptoms without any associated epicardial obstructive coronary artery disease. Regional variations in myocardial oxygenation on OS-CMR could serve as an important diagnostic marker for microvascular dysfunction in women with ANOCA.

Automated Data Transformation and Feature Extraction for Oxygenation-Sensitive Cardiovascular Magnetic Resonance Images.

Oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR) is a novel, powerful tool for assessing coronary function in vivo. The data extraction and analysis however are labor-intensive. The objective of this study was to provide an automated approach for the extraction, visualization, and biomarker selection of OS-CMR images. We created a Python-based tool to automate extraction and export of raw patient data, featuring 3336 attributes per participant, into a template compatible with common data analytics frameworks, including the functionality to select predictive features for the given disease state. Each analysis was completed in about 2 min. The features selected by both ANOVA and MIC significantly outperformed (p < 0.001) the null set and complete set of features in two datasets, with mean AUROC scores of 0.89eatures f 0.94lete set of features in two datasets, with mean AUROC scores that our tool is suitable for automated data extraction and analysis of OS-CMR images.

The reproducibility of breathing maneuvers as a vasoactive stimulus in the heart: an oxygenation-sensitive resonance imaging study.

BACKGROUND: Endothelial dysfunction and impaired oxygenation of the heart is a hallmark of several diseases, including coronary artery disease, hypertension, diabetes, and sleep apnea. Recent studies indicate that oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR) imaging combined with breathing maneuvers may allow for assessing coronary vascular responsiveness as a marker for coronary vascular function in various clinical settings. However, despite the use of OS-CMR in evaluating tissue oxygenation, the reproducibility of these standardized, combined breathing maneuvers as a vasoactive stimulus has yet to be systematically assessed or validated. In this study, we aimed to assess the reproducibility of vasoactive breathing maneuvers to assess vascular function in a population of healthy volunteers. METHODS: Eighteen healthy volunteers were recruited for the study. Inclusion criteria were an age over 18 years and absence of any evidence or knowledge of cardiovascular, neurological, or pulmonary disease. MRI was performed on a clinical 3 T MRI system (MAGNETOM Skyra, Siemens Healthineers, Erlangen, Germany). The OS-CMR acquisition was performed as previously described (1 min hyperventilation followed by a maximal, voluntary breath-hold). Standard statistical tests were performed as appropriate. RESULTS: Data from 18 healthy subjects was analyzed. The healthy volunteers had a mean age of 42 ± 15 years and a mean BMI of 25.4 ± 2.8 kg/m2, with an average heart rate of 72 ± 11 beats per minute, and ten of whom (56%) were female. There were no significant differences between global myocardial oxygenation (%[Formula: see text] SI) after hyperventilation (HV1: - 7.82 [Formula: see text] 5.2; HV2: - 7.89 [Formula: see text] 6.4, p = 0.9) or breath-hold (BH1: 5.34 [Formula: see text] 3.1; BH2: 6.0 [Formula: see text] 3.3, p = 0.5) between the repeated breathing maneuvers. The Bland-Altman analysis showed good agreement (bias: 0.074, SD of bias: 2.93). CONCLUSION: We conclude that in healthy individuals, the myocardial oxygenation response to a standardized breathing maneuver with hyperventilation and a voluntary breath-hold is consistent and highly reproducible. These results corroborate previous evidence for breathing-enhanced OS-CMR as a robust test for coronary vascular function.

Microvascular Dysfunction as a Possible Link Between Heart Failure and Cognitive Dysfunction.

BACKGROUND: Microvascular function in the brain and heart may play an important role in the course of patients with heart failure (HF), but its relationship with ventricular and cognitive function is not well understood. We hypothesized that microvascular function in HF is closely related to both, cardiac and cognitive function. METHODS: In healthy controls and symptomatic patients with HF (New York Heart Association functional class II or III), we used oxygenation-sensitive magnetic resonance imaging during a standardized breathing maneuver to determine the cerebral oxygenation reserve and the myocardial oxygenation reserve (MORE) as markers for microvascular function. A stepwise multivariable linear regression was performed to determine the variables that best predict changes in cerebral oxygenation reserve and MORE. We also measured cognitive function using the Montreal Cognitive Assessment test. RESULTS: Twenty patients with HF (age 64.4±8.3 years; 50% female sex), and 21 healthy controls (age 55.0±5.1 years; 62% female sex) were included in the analysis. In patients with HF, cerebral oxygenation reserve and MORE were lower than in healthy controls (MORE, -0.1±3.3 versus 5.0±4.2, cerebral oxygenation reserve: 0.43±0.47 versus 1.21±0.60, respectively) as were Montreal Cognitive Assessment score results (HF, 23.9±3.7; healthy, 27.8±1.5; P=0.002). The Montreal Cognitive Assessment score in patients was correlated with cardiac output (r=0.55, P=0.011) and MORE (r=0.46, P=0.040). In addition to the presence of HF, significant predictors of cerebral and myocardial oxygenation reserve were cardiac output and end-diastolic volume, respectively. CONCLUSIONS: Our results indicate that heart failure is an independent predictor of coronary and cerebral microvascular dysfunction as defined by a reduced response to a vasodilatory breathing maneuver. This impaired response was associated with reduced cognitive function.

Canadian radiology workforce demographics: Results from a national survey.

Rationale and objective: Demographic data collected about Canadian radiologists and trainees has been limited primarily to binary gender and geographic location. The purpose of this study was to investigate: (1) demographic characteristics of Canadian radiologists and trainees; (2) types of diversity important to radiologists; (3) relationship of radiologist demographics to practice characteristics; and (4) relationship of radiologist demographics to years in practice, (YIP). Materials and methods: French and English surveys were distributed via email through radiology associations and social media. Frequency counts of demographic variables were calculated, and chi-square and Fisher's Exact tests were performed to explore the relationships between demographic characteristics and role. Results: 611 individuals responded to the survey. 573 respondents were included in the analysis. 454 (78.8%) were practicing radiologists and 119 (20.7%) were residents/fellows. Half identified as women (50.4%). English was the primary language for most respondents. There was an association between role and sexual orientation (p = 0.02), visible minority (χ2 = 4.79, p < 0.05), religion (χ2 = 4.11, p < 0.05), and having children (χ2 = 136.65, p < 0.05). For radiologists, being a visible minority (χ2 = 11.59, p < 0.05) and age (χ2 = 56.3, p < 0.05) were associated with academic rank while gender (χ2 = 3.83, p < 0.05) and age (χ2 = 13.74, p < 0.05) were related to part-/full-time status. Less women, visible minorities, and women with children had been in practice for long. Discussion: This study represents a comprehensive analysis of Canadian radiology demographics. Results suggest there is increasing diversity among trainees; however, significant demographic underrepresentation compared to the diversity of Canada exists.

Dynamic Cardiac Magnetic Resonance Fingerprinting During Vasoactive Breathing Maneuvers: First Results.

BACKGROUND: Cardiac magnetic resonance fingerprinting (cMRF) enables simultaneous mapping of myocardial T1 and T2 with very short acquisition times. Breathing maneuvers have been utilized as a vasoactive stress test to dynamically characterize myocardial tissue in vivo. We tested the feasibility of sequential, rapid cMRF acquisitions during breathing maneuvers to quantify myocardial T1 and T2 changes. METHODS: We measured T1 and T2 values using conventional T1 and T2-mapping techniques (modified look locker inversion [MOLLI] and T2-prepared balanced-steady state free precession), and a 15 heartbeat (15-hb) and rapid 5-hb cMRF sequence in a phantom and in 9 healthy volunteers. The cMRF5-hb sequence was also used to dynamically assess T1 and T2 changes over the course of a vasoactive combined breathing maneuver. RESULTS: In healthy volunteers, the mean myocardial T1 of the different mapping methodologies were: MOLLI 1,224 ± 81 ms, cMRF15-hb 1,359 ± 97 ms, and cMRF5-hb 1,357 ± 76 ms. The mean myocardial T2 measured with the conventional mapping technique was 41.7 ± 6.7 ms, while for cMRF15-hb 29.6 ± 5.8 ms and cMRF5-hb 30.5 ± 5.8 ms. T2 was reduced with vasoconstriction (post-hyperventilation compared to a baseline resting state) (30.15 ± 1.53 ms vs. 27.99 ± 2.07 ms, p = 0.02), while T1 did not change with hyperventilation. During the vasodilatory breath-hold, no significant change of myocardial T1 and T2 was observed. CONCLUSIONS: cMRF5-hb enables simultaneous mapping of myocardial T1 and T2, and may be used to track dynamic changes of myocardial T1 and T2 during vasoactive combined breathing maneuvers.

A context-dependent switch from sensing to feeling in the primate amygdala.

The skin transmits affective signals that integrate into our social vocabulary. As the socio-affective aspects of touch are likely processed in the amygdala, we compare neural responses to social grooming and gentle airflow recorded from the amygdala and the primary somatosensory cortex of non-human primates. Neurons in the somatosensory cortex respond to both types of tactile stimuli. In the amygdala, however, neurons do not respond to individual grooming sweeps even though grooming elicits autonomic states indicative of positive affect. Instead, many show changes in baseline firing rates that persist throughout the grooming bout. Such baseline fluctuations are attributed to social context because the presence of the groomer alone can account for the observed changes in baseline activity. It appears, therefore, that during grooming, the amygdala stops responding to external inputs on a short timescale but remains responsive to social context (or the associated affective states) on longer time scales.

Canadian Radiology Gender Pay Gap-Reality or Myth?

Introduction: Prior studies on Canadian physicians' income have demonstrated a gender pay gap (GPG); however, there is a paucity of data in the Radiology specialty. A cross-sectional study was conducted to determine if practicing Canadian radiologists' self-reported income is related to gender, controlling for demographic and work variables. Methods: English and French online surveys were distributed by email and social media to radiologists and trainees (May-July 2021). The association between Gender (controlling for Ethnicity variables, Region, having Children, Full-/Part-Time work, and Academic position) and Self-Reported Income was examined using chi-square tests. Pearson correlations examined relationships between opinion variables. Analyses were conducted using SPSS V28.0. A priori significance was P < .05. Study had ethics approval. Results: Four hundred and fifty-four practicing Canadian radiologists responded. Majority were women (51.2%, n = 227), a non-visible Minority (71.7%, n = 317), and from Western Provinces (67.8%, n = 308). Significant relationship was established between Self-Reported Income and Gender (χ2 = 10.44, df = 2, P < .05). More men (70.6%, n = 120) than women (56.4%, n = 110), reported income "greater than $500 000"; fewer men (20.6%, n = 35) than women (35.9%, n = 70) reported "$300 000-$500 000"; a similar percent of men (8.8%, n = 15) and women (7.7%, n = 15) reported "less than $300 000." No relationship was found between self-reported income and gender for ethnicity variables, those without children, part-time, or non-academic radiologists. The opinion "Addressing the GPG is important" correlated to "Canadian Association of Radiologists should collect demographic data" (r = 0.63). Responses were low for ethnic minorities and non-western provinces. Conclusion: Our results suggest a GPG exists in Canadian radiology and is an important first step for future studies.

Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction.

Oxygenation-sensitive cardiac magnetic resonance imaging (OS-CMR) is a diagnostic technique that uses the inherent paramagnetic properties of deoxyhemoglobin as an endogenous source of tissue contrast. Used in combination with standardized vasoactive breathing maneuvers (hyperventilation and apnea) as a potent non-pharmacologic vasomotor stimulus, OS-CMR can monitor changes in myocardial oxygenation. Quantifying such changes during the cardiac cycle and throughout vasoactive maneuvers can provide markers for coronary macro- and microvascular function and thereby circumvent the need for any extrinsic, intravenous contrast or pharmacologic stress agents. OS-CMR uses the well-known sensitivity of T2*-weighted images to blood oxygenation. Oxygenation-sensitive images can be acquired on any cardiac MRI scanner using a modified standard clinical steady-state free precession (SSFP) cine sequence, making this technique vendor-agnostic and easily implemented. As a vasoactive breathing maneuver, we apply a 4 min breathing protocol of 120 s of free breathing, 60 s of paced hyperventilation, followed by an expiratory breath-hold of at least 30 s. The regional and global response of myocardial tissue oxygenation to this maneuver can be assessed by tracking the signal intensity change. The change over the initial 30 s of the post-hyperventilation breath-hold, referred to as the breathing-induced myocardial oxygenation reserve (B-MORE) has been studied in healthy people and various pathologies. A detailed protocol for performing oxygen-sensitive CMR scans with vasoactive maneuvers is provided. As demonstrated in patients with microvascular dysfunction in yet incompletely understood conditions, such as inducible ischemia with no obstructive coronary artery stenosis (INOCA), heart failure with preserved ejection fraction (HFpEF), or microvascular dysfunction after heart transplantation, this approach provides unique, clinically important, and complementary information on coronary vascular function.

A head-to-head comparison of fast-SENC and feature tracking to LV long axis strain for assessment of myocardial deformation in chest pain patients.

BACKGROUND: Myocardial strain imaging has gained importance in cardiac magnetic resonance (CMR) imaging in recent years as an even more sensitive marker of early left ventricular dysfunction than left-ventricular ejection fraction (LVEF). fSENC (fast strain encoded imaging) and FT (feature tracking) both allow for reproducible assessment of myocardial strain. However, left-ventricular long axis strain (LVLAS) might enable an equally sensitive measurement of myocardial deformation as global longitudinal or circumferential strain in a more rapid and simple fashion. METHODS: In this study we compared the diagnostic performance of fSENC, FT and LVLAS for identification of cardiac pathology (ACS, cardiac-non-ACS) in patients presenting with chest pain (initial hscTnT 5-52 ng/l). Patients were prospectively recruited from the chest pain unit in Heidelberg. The CMR scan was performed within 1 h after patient presentation. Analysis of LVLAS was compared to the GLS and GCS as measured by fSENC and FT. RESULTS: In total 40 patients were recruited (ACS n = 6, cardiac-non-ACS n = 6, non-cardiac n = 28). LVLAS was comparable to fSENC for differentiation between healthy myocardium and myocardial dysfunction (GLS-fSENC AUC: 0.882; GCS-fSENC AUC: 0.899; LVLAS AUC: 0.771; GLS-FT AUC: 0.740; GCS-FT: 0.688), while FT-derived strain did not allow for differentiation between ACS and non-cardiac patients. There was significant variability between the three techniques. Intra- and inter-observer variability (OV) was excellent for fSENC and FT, while for LVLAS the agreement was lower and levels of variability higher (intra-OV: Pearson > 0.7, ICC > 0.8; inter-OV: Pearson > 0.65, ICC > 0.8; CoV > 25%). CONCLUSIONS: While reproducibility was excellent for both FT and fSENC, it was only fSENC and the LVLAS which allowed for significant identification of myocardial dysfunction, even before LVEF, and therefore might be used as rapid supporting parameters for assessment of left-ventricular function.

Evaluation of call volume and negative emotions in emergency response system telecommunicators: a prospective, intensive longitudinal investigation.

Emergency telecommunicators are essential first responders tasked with coordinated communication within the emergency response system (ERS). Despite their exposure to significant job demands, little is known about the effect of call load or call type on emotional state within these workers. Therefore, we employed a prospective, intensive longitudinal design to examine whether emergency-eligible call volume would lead to higher intensity negative emotions post-shift when controlling for pre-shift negative emotions and a number of other work and individual factors, including work duration and night shift. A total of 47 ERS telecommunicators (dispatchers, operators, other) completed ratings over working shifts within a two-week period. Call frequency was gathered through the agency Computer-Assisted Dispatch database. Negative emotions of irritation, stress, worry, and fatigue were measured through the Visual Analogue Scale administered before and after shift. Mixed linear modeling demonstrated that telecommunicators who received more calls per hour (Estimate = 3.56, SE = 1.44, p < 0.05) and more-than-usual calls per hour (Estimate = 1.97, SE = .94, p < 0.05) had higher levels of post-shift irritability. Longer-than-usual working hours also predicted higher levels of post-shift irritability (Estimate = 1.32, SE = 0.59, p < 0.05). Call volume did not predict other negative emotions, although secondary analyses demonstrated that a larger number of chronic calls lead to greater levels of post-shift worry. ERS telecommunication agencies aiming to reduce negative emotions in workers may benefit from implementing policies and programs that target working hours, call load, and work-life balance.

The Potential of Oxygenation-Sensitive CMR in Heart Failure.

PURPOSE OF REVIEW: Cardiac magnetic resonance imaging (CMR) use in the context of heart failure (HF) has increased over the last decade as it is able to provide detailed, quantitative information on function, morphology, and myocardial tissue composition. Furthermore, oxygenation-sensitive CMR (OS-CMR) has emerged as a CMR imaging method capable of monitoring changes of myocardial oxygenation without the use of exogenous contrast agents. RECENT FINDINGS: The contributions of OS-CMR to the investigation of patients with HF includes not only a fully quantitative assessment of cardiac morphology, function, and tissue characteristics, but also high-resolution information on both endothelium-dependent and endothelium-independent vascular function as assessed through changes of myocardial oxygenation. In patients with heart failure, OS-CMR can provide deep phenotyping on the status and important associated pathophysiology as a one-stop, needle-free diagnostic imaging test.

The Status of Diversity in Canadian Radiology-Where We Stand and What Can We Do About It.

Radiology has been identified as one of the medical specialties with the least gender, racial, and ethnic diversity. Despite the demonstrated benefits of gender and race diversity in medicine and industry, including innovation, empathy and improved patient outcomes, diversity in radiology in Canada is still lacking. In 2019, women represented around 63% of current medical graduates. However, within Canadian radiology practices, only 31.6% of radiologists are women. Women are also underrepresented in academic positions and the widening gender gap is present at higher academic ranks, indicating that women may not advance through academic hierarchies at the same pace as men. Although data on racial diversity in Canadian radiology practices is currently lacking, the representation of visible minorities in the general Canadian population is not reflected across Canadian radiology practices. Similarly, despite the Canadian Truth and Reconciliation Commission calling for action to increase the number of Indigenous healthcare workers, Indigenous people remain underrepresented in medicine and radiology. The importance of increasing diversity in radiology has gained recognition in recent years. Many solutions and strategies for national associations and radiology departments to improve diversity have been proposed. Leadership commitment is required to implement these programs to increase diversity in radiology in Canada with the ultimate goal of improving patient care. We review the current literature and available data on diversity within radiology in Canada, including the status of gender, race/ethnicity, and Indigenous people. We also present potential solutions to increase diversity.

Recovery Sleep versus Emotion Regulation in Predicting Fire Service Shift Workers Stress, Fatigue and Irritability.

Objective/Background: Fire service shift workers are at risk of developing mental health difficulties related to sleep loss and emotion dysregulation. We aimed to clarify the relationship between off-shift recovery sleep and emotion regulation on stress, fatigue and irritability. Participants: A total of 61 fire service shift workers (e.g. firefighter, captain, engineer, paramedic) on a "5/6" shift. Methods: Following five 24-hour shifts, participants reported on emotion regulation as well as daily sleep, stress, fatigue and irritability during six consecutive off-shift recovery days. Mediation analyses examined (1) emotion regulation as a predictor and sleep as a mediator of stress, fatigue and irritability outcomes; and (2) sleep as a predictor and emotion regulation as a mediator of stress, fatigue and irritability outcomes. Results: Greater self-reported total sleep time predicted lower recovery stress, fatigue, and irritability. Greater subjective sleep efficiency predicted lower recovery stress and fatigue, but not irritability. No significant relationships emerged for objective sleep or emotion regulation variables predicting stress, fatigue or irritability. There were no significant findings with either emotion regulation or sleep variables included as mediators. Conclusions: These findings suggest that stress management programs for fire service shift workers may be most effective when targeting sleep efficiency and quantity rather than emotion regulation strategies in the off-shift recovery period.

Hyperventilation-induced heart rate response as a potential marker for cardiovascular disease.

An increase of heart rate to physical or mental stress reflects the ability of the autonomous nervous system and the heart to respond adequately. Hyperventilation is a user-controlled breathing maneuver that has a significant impact on coronary function and hemodynamics. Thus, we aimed to investigate if the heart rate response to hyperventilation (HRRHV) can provide clinically useful information. A pooled analysis of the HRRHV after 60 s of hyperventilation was conducted in 282 participants including healthy controls; patients with heart failure (HF); coronary artery disease (CAD); a combination of both; or patients suspected of CAD but with a normal angiogram. Hyperventilation significantly increased heart rate in all groups, although healthy controls aged 55 years and older (15 ± 9 bpm) had a larger HRRHV than each of the disease groups (HF: 6 ± 6, CAD: 8 ± 8, CAD+/HF+: 6 ± 4, and CAD-/HF-: 8 ± 6 bpm, p < 0.001). No significant differences were found between disease groups. The HRRHV may serve as an easily measurable additional marker of cardiovascular health. Future studies should test its diagnostic potential as a simple, inexpensive pre-screening test to improve patient selection for other diagnostic exams.