Electrocardiographic Findings in Female Professional Basketball Athletes

Importance

Previous studies of professional basketball athletes have characterized manifestations of athletic remodeling by echocardiography and electrocardiography (ECG) in males and echocardiography in females. There is a paucity of female, basketball-specific ECG data.

Objective

To generate reference range ECG data for female professional basketball athletes.

Design, Setting, and Participants

This is a cross-sectional study of ECGs performed on female professional basketball athletes. The Women's National Basketball Association mandates annual preseason ECGs and echocardiograms for each athlete and has partnered with Columbia University Irving Medical Center to annually review these studies. Data for this study were collected during preseason ECG and echocardiography cardiac screening between April and May 2022. Data analysis was performed between February and July 2023.

Exposure

Athlete ECGs and echocardiograms were sent to Columbia University Irving Medical Center for core lab analysis.

Main Outcomes and Measures

Quantitative ECG variables were measured. ECG data were qualitatively analyzed for training-related and abnormal findings using the International Recommendations for Electrocardiographic Interpretation in Athletes. Findings from ECGs were compared with corresponding echocardiographic data.

Results

There were a total of 173 athletes (mean [SD] age 26.5 [4.1] years; mean [SD] height, 183.4 [9.1] cm; mean [SD] body surface area, 2.0 [0.2] m2), including 129 Black athletes (74.5%) and 40 White athletes (23.1%). By international criteria, 136 athletes (78.6%) had training-related ECG changes and 8 athletes (4.6%) had abnormal ECG findings. Among athletes with at least 1 training-related ECG finding, left ventricular structural adaptations associated with athletic remodeling were present in 64 athletes (47.1%). Increased relative wall thickness, reflecting concentric left ventricular geometry, was more prevalent in athletes with the repolarization variant demonstrating convex ST elevation combined with T-wave inversions in leads V1 to V4 (6 of 12 athletes [50.0%]) than in athletes with early repolarization (5 of 42 athletes [11.9%]) (odds ratio, 7.40; 95% CI, 1.71-32.09; P = .01). Abnormal ECG findings included T-wave inversions (3 athletes [1.7%]), Q waves (2 athletes [1.2%]), prolonged QTc interval (2 athletes [1.2%]), and frequent premature ventricular contractions (1 athlete [0.6%]).

Conclusions and Relevance

This cross-sectional study provides reference ECG data for elite female basketball athletes. International criteria-defined training-related findings were common, whereas abnormal ECG findings were rare in this athlete group. These reference data may assist basketball programs and health care professionals using ECGs in screening for female athletes and may be used as a stimulus for future female-specific ECG inquiries.

HIV and COVID-19: two pandemics with significant (but different) central nervous system complications

Human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause significant neurologic disease. Central nervous system (CNS) involvement of HIV has been extensively studied, with well-documented invasion of HIV into the brain in the initial stage of infection, while the acute effects of SARS-CoV-2 in the brain are unclear. Neuropathologic features of active HIV infection in the brain are well characterized whereas neuropathologic findings in acute COVID-19 are largely non-specific. On the other hand, neuropathologic substrates of chronic dysfunction in both infections, as HIV-associated neurocognitive disorders (HAND) and post-COVID conditions (PCC)/long COVID are unknown. Thus far, neuropathologic studies on patients with HAND in the era of combined antiretroviral therapy have been inconclusive, and autopsy studies on patients diagnosed with PCC have yet to be published. Further longitudinal, multidisciplinary studies on patients with HAND and PCC and neuropathologic studies in comparison to controls are warranted to help elucidate the mechanisms of CNS dysfunction in both conditions.

Racial/Ethnic Disparities in Outcomes After Percutaneous Coronary Intervention

Asian American/Pacific Islanders (AAPIs) and Hispanics are growing minority United States populations, but are poorly represented in the cardiovascular literature. This study examines guideline adherence and outcomes in AAPIs and Hispanics compared with non-Hispanic Whites (NHWs) in a quaternary care center after inpatient percutaneous coronary intervention (PCI). The primary end points were inpatient post-PCI bleed, heart failure, cardiogenic shock, and all-cause mortality, whereas the secondary end point was the prescription rate of post-PCI guideline-directed medical therapy including aspirin, statins, P2Y12 receptor blockers, and cardiopulmonary rehabilitation. Intergroup differences were assessed through analysis of variance or two-way chi-square tests, and the association of race with binary outcomes was examined through logistic regression with NHW as the reference group. Compared with NHW, AAPIs, and Hispanics had higher odds of diabetes mellitus, and AAPIs had higher odds of hypertension and being on dialysis. Hispanics had higher odds of post-PCI mortality versus NHW, both in acute coronary syndrome (odds ratio [OR] 2.04, p = 0.03) and elective PCI (OR 2.51, p = 0.04). AAPI also trended toward higher mortality than NHW in both categories. AAPIs were found to have higher odds of statin prescription (OR 1.91, p = 0.04). Hispanics had lower odds of ticagrelor prescription versus NHW (OR 0.65, p = 0.04), and AAPIs trended toward such. No differences were found for cardiopulmonary rehabilitation prescriptions in groups. This study suggests that despite quality improvement efforts, disparities remain in postprocedural outcomes in minority groups in comparison with NHW.

A wireless patch for the monitoring of C-reactive protein in sweat

The quantification of protein biomarkers in blood at picomolar-level sensitivity requires labour-intensive incubation and washing steps. Sensing proteins in sweat, which would allow for point-of-care monitoring, is hindered by the typically large interpersonal and intrapersonal variations in its composition. Here we report the design and performance of a wearable and wireless patch for the real-time electrochemical detection of the inflammatory biomarker C-reactive (CRP) protein in sweat. The device integrates iontophoretic sweat extraction, microfluidic channels for sweat sampling and for reagent routing and replacement, and a graphene-based sensor array for quantifying CRP (via an electrode functionalized with anti-CRP capture antibodies-conjugated gold nanoparticles), ionic strength, pH and temperature for the real-time calibration of the CRP sensor. In patients with chronic obstructive pulmonary disease, with active or past infections or who had heart failure, the elevated concentrations of CRP measured via the patch correlated well with the protein's levels in serum. Wearable biosensors for the real-time sensitive analysis of inflammatory proteins in sweat may facilitate the management of chronic diseases.

DASH-HF Study: A Pragmatic Quality Improvement Randomized Implementation Trial for Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Heart failure is a prevailing diagnosis of hospitalization and readmission within 6 months, and nearly a quarter of these patients die within a year. Guideline-directed medication therapies reduce risk of mortality by 73% over 2 years; however, the implementation of these therapies to their target dose in clinical practice continues to be challenging. In 2020, the Veterans Affairs (VA) Health Care System developed a HF dashboard to monitor and improve outpatient HF management. The DASH-HF (Dashboard Activated Services and Telehealth for Heart Failure) study is a randomized, pragmatic clinical trial to evaluate proactive dashboard-directed telehealth clinics to improve the use and dosing of guideline-directed medication therapy for patients with heart failure with reduced ejection fraction not on optimal guideline-directed medication therapy within the VA.

METHODS

Three hundred veterans with heart failure with reduced ejection fraction met inclusion criteria with an optimization potential score (OPS) of 5 or less out of 10, representing nonoptimal guideline-directed medication therapy. The primary outcome was a composite score of guideline-directed medical therapy, the OPS, 6 months after the end of the intervention. Secondary outcomes included active prescriptions for each individual guideline-directed medical therapy class, HF-related hospitalizations, deaths, and clinician time per patient during the intervention clinics.

RESULTS

There was no significant difference between the intervention arm and usual care group in the primary outcome (OPS, 2.9; SD=2.1 versus OPS, 2.6, SD=2.1); adjusted mean difference 0.3 (95% CI, -0.1 to 0.7) or in the prespecified secondary outcomes for hospitalization and all-cause mortality for the intervention of proactive dashboard-based clinics.

CONCLUSIONS

A dashboard-based clinic intervention did not improve the OPS or secondary outcomes of hospitalization and all-cause mortality. There remains a larger opportunity to better target patients and provide more intensive follow-up to further evaluate the utility of proactive dashboard-based clinics for HF management and quality improvement.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05001165.

Sudden cardiac arrest in athletes and strategies to optimize preparedness

Sudden cardiac arrest (SCA) is the leading cause of death in young athletes. Despite efforts to improve preparedness for cardiac emergencies, the incidence of out-of-hospital cardiac arrests in athletes remains high, and bystander awareness and readiness for SCA support are inadequate. Initiatives such as designing an emergency action plan (EAP) and mandating training in cardiopulmonary resuscitation (CPR) and automated external defibrillator use (AED) for team members and personnel can contribute to improved survival rates in SCA cases. This review provides an overview of SCA in athletes, focusing on identifying populations at the highest risk and evaluating the effectiveness of different screening practices in detecting conditions that may lead to SCA. We summarize current practices and recommendations for improving the response to SCA events, and we highlight the need for ongoing efforts to optimize preparedness through the implementation of EAPs and the training of individuals in CPR and AED use. Additionally, we propose a call to action to increase awareness and training in EAP development, CPR, and AED use for team members and personnel. To improve outcomes of SCA cases in athletes, it is crucial to enhance bystander awareness and preparedness for cardiac emergencies. Implementing EAPs and providing training in CPR and AED use for team members and personnel are essential steps toward improving survival rates in SCA cases.

Effects of activity levels on aortic calcification in hyperlipidemic mice as measured by microPETmicroCT

BACKGROUND AND AIMS

Cardiovascular disease risk is associated with coronary artery calcification and is mitigated by regular exercise. Paradoxically, elite endurance athletes, who have low risk, are likely to have more coronary calcification, raising questions about the optimal level of activity.

METHODS

Female hyperlipidemic (Apoe-/-) mice with baseline aortic calcification were subjected to high-speed (18.5 m/min), low-speed (12.5 m/min), or no treadmill exercise for 9 weeks. 18F-NaF microPET/CT images were acquired at weeks 0 and 9, and echocardiography was performed at week 9.

RESULTS

In controls, aortic calcium content and density increased significantly. Exercise regimens did not alter the time-dependent increase in content, but the increase in mean density was blunted. Interestingly, the low-speed regimen significantly reduced 18F-NaF uptake, a marker of surface area. Left ventricular (LV) systolic function was lower while LV diameter was greater in the low-speed group compared with controls or the high-speed group. In the low-speed group, vertebral bone density by CT decreased significantly, contrary to expectations. Male hyperlipidemic (Apoe-/-) mice were fed a Western diet and also subjected to low-speed or no exercise followed by imaging at weeks 0 and 9. In males, exercise also did not alter the time-dependent increase in aortic calcification. Exercise did not affect 18F-NaF uptake or bone mineral density, but it blunted the diet-induced LV hypertrophy seen in controls.

CONCLUSIONS

These results suggest that, in mice, exercise has differential effects on aortic calcification, cardiac function, and skeletal bone mineral density.

Accelerated Cardiac Allograft Vasculopathy in an Orthotopic Heart Transplant Recipient with Prior COVID-19

BACKGROUND Cardiac allograft vasculopathy (CAV) is a post-orthotopic heart transplant (OHT) complication driven by intimal smooth muscle proliferation and immune hyperactivity to donor heart tissue. Accelerated CAV leads to allograft failure within 1 year after receiving a normal angiogram result. Viruses can contribute to CAV development, but CAV after SARS-CoV-2 infection has not been reported to date. CASE REPORT A 48-year-old man, 5 years after OHT for non-ischemic cardiomyopathy, was admitted to the Cardiac Care Unit with 3 days of abdominal pain, dyspnea, and palpitations. His medical history included hyperlipidemia and insulin-dependent diabetes. He was compliant with all medications. Two months prior, he had a mild COVID-19 case. An echocardiogram and coronary angiogram 6 and 9 months prior, respectively, were unremarkable. Right and left heart catheterization demonstrated increased filling pressures, a cardiac index of 1.7 L/ml/m², and diffuse vasculopathy most severe in the LAD artery. Flow could not be restored despite repeated ballooning and intra-catheter adenosine. Empiric ionotropic support, daily high-dose methylprednisolone, and plasmapheresis were started. A few days later, the patient had cardiac arrest requiring venoarterial extracorporeal membranous oxygenation. Given CAV's irreversibility, re-transplantation was considered, but the patient had an episode of large-volume hemoptysis and remained clinically unstable for transplant. The patient died while on palliative care. CONCLUSIONS Our patient developed accelerated CAV 2 months after having COVID-19. While CAV has known associations with certain viruses, its incidence after SARS-CoV-2 infection is unknown. Further research is needed to determine if prior SARS-CoV-2 infection is a risk factor for development of CAV in OHT recipients.

Potential mechanisms linking high-volume exercise with coronary artery calcification

Recent studies have found an association between high volumes of physical activity and increased levels of coronary artery calcification (CAC) among older male endurance athletes, yet the underlying mechanisms have remained largely elusive. Potential mechanisms include greater exposure to inflammatory cytokines, reactive oxygen species and oxidised low-density lipoproteins, as acute strenuous physical activity has been found to enhance their systemic release. Other possibilities include post-exercise elevations in circulating parathyroid hormone, which can modify the amount and morphology of calcific plaque, and long-term exposure to non-laminar blood flow within the coronary arteries during vigorous physical activity, particularly in individuals with pre-existing atherosclerosis. Further, although the association has only been identified in men, the role of testosterone in this process remains unclear. This brief review discusses the association between high-volume endurance exercise and CAC in older men, elaborates on the potential mechanisms underlying the increased calcification, and provides clinical implications and recommendations for those at risk.

Wearable technology in the sports medicine clinic to guide the return-to-play and performance protocols of athletes following a COVID-19 diagnosis

The coronavirus disease 2019 (COVID-19) pandemic has enabled the adoption of digital health platforms for self-monitoring and diagnosis. Notably, the pandemic has had profound effects on athletes and their ability to train and compete. Sporting organizations worldwide have reported a significant increase in injuries manifesting from changes in training regimens and match schedules resulting from extended quarantines. While current literature focuses on the use of wearable technology to monitor athlete workloads to guide training, there is a lack of literature suggesting how such technology can mediate the return to sport processes of athletes infected with COVID-19. This paper bridges this gap by providing recommendations to guide team physicians and athletic trainers on the utility of wearable technology for improving the well-being of athletes who may be asymptomatic, symptomatic, or tested negative but have had to quarantine due to a close exposure. We start by describing the physiologic changes that occur in athletes infected with COVID-19 with extended deconditioning from a musculoskeletal, psychological, cardiopulmonary, and thermoregulatory standpoint and review the evidence on how these athletes may safely return to play. We highlight opportunities for wearable technology to aid in the return-to-play process by offering a list of key parameters pertinent to the athlete affected by COVID-19. This paper provides the athletic community with a greater understanding of how wearable technology can be implemented in the rehabilitation process of these athletes and spurs opportunities for further innovations in wearables, digital health, and sports medicine to reduce injury burden in athletes of all ages.

Early trends in cardiac allograft vasculopathy after implementation of the 2018 donor heart allocation policy in the United States

STUDY OBJECTIVE

To evaluate the impact of the new donor heart allocation system implemented in the United States in October 2018 on development of early cardiac allograft vasculopathy (CAV).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Adult (≥ 18 years) heart transplant recipients registered in the United Network for Organ Sharing database between October 18, 2015 and October 17, 2018 (old system) and October 18, 2018 and May 31, 2020 (new system).

MAIN OUTCOME MEASURE

Incidence of angiographic CAV at 1 year (accelerated CAV) in the overall transplant population and among the highest acuity subgroup-Status 1A (old) and Status 1 or 2 (new). We included recipient and donor demographic, cardiovascular, and transplant factors in multivariable logistic regression models to identify predictors of accelerated CAV.

RESULTS

Of 10,375 transplant recipients, 6,660 (64%) and 3,715 (36%) were listed in the old and new allocation cohorts, respectively. The incidence of accelerated CAV was 521 (8%) in the old period compared with 272 (7%) in the new period (P = .36). Similar incidence rates were observed in the highest acuity subgroup-363 (8%) compared with 143 (7%), respectively (P = .13). In adjusted analyses of the high-acuity cohort, the new allocation system was not associated with a higher likelihood of accelerated CAV (odds ratio = 0.87, 95% confidence interval: 0.70-1.08, P = .20).

CONCLUSIONS

The new donor heart allocation system is not associated with development of accelerated angiographic CAV at 1 year, including among recipients requiring the most urgent transplants.

Postural orthostatic tachycardia syndrome and orthostatic hypotension in post-acute sequelae of COVID-19 during pregnancy: a case report

BACKGROUND

Patients with post-acute sequelae of COVID-19 (PASC) often experience the addition of new symptoms after recovery from COVID-19 illness. These may include orthostatic intolerance and autonomic dysfunction, and postural orthostatic tachycardia syndrome has been described to occur in a proportion of patients with PASC.

CASE SUMMARY

In this report, we present a 32-year-old pregnant woman (G3P2) who experiences severe orthostatic symptoms as part of her PASC syndrome, which is decoupled from normal physiologic changes of pregnancy. At 25 weeks of gestation, she was evaluated for increasing episodes of dyspnoea, marked tachycardia with minimal exertion, intermittent non-exertional chest pain, and presyncope. This patient had a moderate course of COVID-19 at 12 weeks of gestation, for which she received monoclonal antibody therapy (casirivimab/imdevimab). The patient then had complete resolution of COVID-19 symptoms and felt well for 1 month prior to developing orthostatic symptoms at 25 weeks of gestation. Evaluation with a NASA Lean Test revealed marked orthostatic tachycardia, as well as delayed orthostatic hypotension. Given her COVID-19 illness 4 months prior, PASC involving autonomic dysfunction was diagnosed.

DISCUSSION

Patients with orthostatic symptoms in PASC should be carefully evaluated with dedicated active stand tests, such as the NASA Lean Test, to characterize the autonomic response to standing. In pregnant patients, an understanding of normal pregnancy physiology is crucial to correctly identify abnormal findings in such tests.

Regulation of cardiovascular calcification by lipids and lipoproteins

PURPOSE OF REVIEW

Lipids and lipoproteins have long been known to contribute to atherosclerosis and cardiovascular calcification. One theme of recent work is the study of lipoprotein (a) [Lp(a)], a lipoprotein particle similar to LDL-cholesterol that carries a long apoprotein tail and most of the circulating oxidized phospholipids.

RECENT FINDINGS

In-vitro studies show that Lp(a) stimulates osteoblastic differentiation and mineralization of vascular smooth muscle cells, while the association of Lp(a) with coronary artery calcification continues to have varying results, possibly because of the widely varying threshold levels of Lp(a) chosen for association analyses. Another emerging area in the field of cardiovascular calcification is pathological endothelial-to-mesenchymal transition (EndMT), the process whereby endothelial cell transition into multipotent mesenchymal cells, some of which differentiate into osteochondrogenic cells and mineralize. The effects of lipids and lipoproteins on EndMT suggest that they modulate cardiovascular calcification through multiple mechanisms. There are also emerging trends in imaging of calcific vasculopathy, including: intravascular optical coherence tomography for quantifying plaque characteristics, PET with a radiolabeled NaF tracer, with either CT or MRI to detect coronary plaque vulnerability.

SUMMARY

Recent work in this field includes studies of Lp(a), EndMT, and new imaging techniques.

Orthostatic and Exercise Intolerance in Recreational and Competitive Athletes With Long COVID

Post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (PASC) infection is particularly concerning to athletes who place a high premium on cardiovascular performance and competition. This initial case series shows the overlap between PASC and orthostatic intolerance in athletes, reveals the diagnostic challenges, and highlights the role of graded exercise training in this population. (Level of Difficulty: Advanced.)

The design of the Dashboard Activated Services and Telehealth for Heart Failure (DASH-HF) study: A pragmatic quality improvement randomized implementation trial for patients with heart failure with reduced ejection fraction

BACKGROUND

Gaps in the receipt and dosing of guideline-directed medical therapy (GDMT) persist for patients with heart failure with reduced ejection fraction (HFrEF) [1]. In 2020, the Veterans Affairs (VA) developed a heart failure (HF) specific population dashboard to monitor care quality and performance on standard HFrEF performance measures [2].

METHODS

The Dashboard Activated Services and Telehealth for HF (DASH-HF) study is a pragmatic randomized quality improvement study designed to evaluate the utility of proactive population management clinics using the VA's HF dashboard to optimize GDMT for patients with HFrEF. Panel management telemedicine clinics incorporated multidisciplinary clinicians to perform chart review and impromptu telephone encounters to evaluate current HFrEF management and opportunities to optimize GDMT. The study will evaluate the efficacy of proactive panel management to usual care at 6 months as quantified by the GDMT optimization potential score. Secondary outcomes include hospitalizations, mortality, and clinician time per intervention. The study completed enrollment and randomization of 300 participants. The intervention was performed from September to December 2021.

CONCLUSION

DASH-HF will contribute to the literature by evaluating use of the existing VA dashboard to identify HF patients with the lowest adherence to GDMT and proactively target this group for the intervention.

REGISTRATION

https://clinicaltrials.gov/. Unique identifier: NCT05001165.

Hemodynamic effects of COVID-19 vaccination in hospitalized patients awaiting heart transplantation

Background

The hemodynamic effects of pre-transplant vaccination against COVID-19 among heart transplant candidates hospitalized for advanced heart failure remains unknown.

Methods

A retrospective chart review was conducted at a high-volume transplant center from January through December 2021. 22 COVID-19 vaccination events occurred among patients hospitalized for decompensated heart failure while awaiting transplantation. Primary outcomes included inotrope and vasopressor dosages. Secondary outcomes included vital signs, pulmonary artery catheter measurements, diuretic dosages, and renal function. Data were extracted 24 h before through 72 h after vaccination.

Results

One of 22 vaccination events was associated with hemodynamic changes requiring increased inotropic and vasopressor support post-vaccination. In all other cases, transient hemodynamic changes occurred without need for escalated therapy.

Conclusions

COVID-19 vaccination can be administered safely to most critically ill patients with advanced heart failure including those awaiting transplantation. All patients should be monitored closely as some may be susceptible to significant hemodynamic changes.

Abstract 332: Dynamic Changes In Endothelial Cell Mechanotype During Inflammatory Endothelial-to-Mesenchymal Transition

Background: Endothelial-to-mesenchymal transition (EndMT), the process whereby endothelial cells (ECs) transition into multipotent stem cell-like cells, has been implicated in a variety of cardiovascular pathologies, including cardiovascular calcification. EndMT is a dynamic mechanical process that involves detachment of transitioning ECs from adjacent cells and active migration of these cells from the endothelium into the interstitium. While gene and protein expression profiles of ECs undergoing EndMT have been well characterized, less is known about the mechanical properties, or “mechanotype,” of ECs as they undergo EndMT.

Methods/Results: Human aortic endothelial cells (HAEC) were treated with the inflammatory cytokine, tumor necrosis factor-α (TNF-α), to induce inflammatory EndMT. Real-time PCR analyses showed that TNF-α significantly reduced the expression of endothelial markers ( PECAM1, NOS3 ) by 24 hours and significantly increased the expression of mesenchymal markers ( COL1A1, COL3A1, FN1, CNN1 ) starting at 48 hours of treatment. Mechanotyping of EC was performed by evaluating cell deformability with the parallel microfiltration (PMF) technique. PMF is a novel method that determines relative deformability by filtering cells across a porous membrane. Results showed that TNF-α has a biphasic effect on EC deformability, increasing the deformability after 24 hours, while decreasing deformability after 48 hours of treatment. Deformability decreased further with 96 hours of TNF-α treatment. Transwell migration assays revealed that TNF-α increased migration of ECs through a porous membrane, whereas EC migration was not enhanced when assessed by a scratch wound assay.

Conclusion: Our results demonstrate that ECs undergo dynamic changes in their mechanotype during inflammatory EndMT. A deeper understanding of the mechanisms governing these changes may help inform therapeutic targets for EndMT-associated disease processes.

Abstract 15: The Design Of The Dashboard Activated Services And Telehealth For Heart Failure (DASH-HF) Study: A Pragmatic Quality Improvement Randomized Implementation Trial For Patients With Heart Failure With Reduced Ejection Fraction

Heart failure is a leading diagnosis for hospitalization with a high risk of readmission. Despite robust data and recommendations by professional societies, there is a well-documented gap in delivering guideline-directed medical therapy (GDMT) known to reduce hospitalizations and improve mortality for patients with heart failure with reduced ejection fraction (HFrEF). The Dashboard Activated Services and Telehealth for HF (DASH-HF) is a quality improvement initiative to evaluate the effectiveness of proactive population management clinics to optimize use and dosing of GDMT for patients with HFrEF relative to usual care. The study utilizes the existing Veterans Affairs Academic Detailing HF Dashboard to target actionable patients (n=300) with a low optimization potential score (OPS) (Table 1). The intervention clinics utilize multidisciplinary providers (e.g., physicians, pharmacists) to perform chart review and telemedicine visits to address opportunities to optimize GDMT. The primary outcome of the study is the OPS 6 months after the end of the intervention, defined by active prescriptions and prescribed doses for each class of GDMT. Secondary outcomes include differences in hospitalizations and mortality and measures of health service efficiency such as patients contacted per clinic. The intervention duration was September to December 2021, and analysis is planned for June 2022. This is a unique study to systematically identify HFrEF patients with the largest gaps in GDMT and proactively engage with this group. We describe the study design for identifying target patients, logistics of the intervention, patient characteristics, and an overview of barriers faced during the intervention. The Coronavirus disease 2019 pandemic has led to a marked increase in telehealth services. If successful, this study may serve as a key pilot trial for more robust telehealth delivery, targeting patients at highest risk for HF-related hospitalizations and mortality.

Impact of Transitioning from In-Person to Virtual Heart Transplantation Selection Committee Meetings: An Observational Study (Preprint)

Background

Heart transplant selection committee meetings have transitioned from in-person to remote video meetings during the COVID-19 pandemic, but how this impacts committee members and patient outcomes is unknown.

Objective

The aim of this study is to determine the perceived impact of remote video transplant selection meetings on usability and patient care and to measure patient selection outcomes during the transition period from in-person to virtual meetings.

Methods

A 35-item anonymous survey was developed and distributed electronically to the heart transplant selection committee. We reviewed medical records to compare the outcomes of patients presented at in-person meetings (January-March 2020) to those presented during video meetings (March-June 2020).

Results

Among 83 committee members queried, 50 were regular attendees. Of the 50 regular attendees, 24 (48%) were physicians and 26 (52%) were nonphysicians, including nurses, social workers, and coordinators; 46 responses were received, 23 (50%) from physicians and 23 (50%) from nonphysicians, with 41 responses fully completed. Overall, respondents were satisfied with the videoconference format and felt that video meetings did not impact patient care and were an acceptable alternative to in-person meetings. However, 54% (22/41) preferred in-person meetings, with 71% (15/21) of nonphysicians preferring in-person meetings compared to only 35% (7/20) of physicians (P=.02). Of the 46 new patient evaluations presented, there was a statistically nonsignificant trend toward fewer patients initially declined at video meetings compared with in-person meetings (6/24, 25% compared to 10/22, 45%; P=.32).

Conclusions

The transition from in-person to video heart transplant selection committee meetings was well-received and did not appear to affect committee members’ perceived ability to deliver patient care. Patient selection outcomes were similar between meeting modalities.

Outcomes in patients hospitalized for COVID-19 among Asian, Pacific Islander, and Hispanic subgroups in the American Heart Association COVID-19 registry

BACKGROUND

Coronavirus disease 2019 (COVID-19) data from race/ethnic subgroups remain limited, potentially masking subgroup-level heterogeneity. We evaluated differences in outcomes in Asian American/Pacific Islander (AAPI) and Hispanic/Latino subgroups compared with non-Hispanic White patients hospitalized with COVID-19.

METHODS

In the American Heart Association COVID-19 registry including 105 US hospitals, mortality and major adverse cardiovascular events in adults age ≥18 years hospitalized with COVID-19 between March-November 2020 were evaluated. Race/ethnicity groups included AAPI overall and subgroups (Chinese, Asian Indian, Vietnamese, and Pacific Islander), Hispanic/Latino overall and subgroups (Mexican, Puerto Rican), compared with non-Hispanic White (NHW).

RESULTS

Among 13,511 patients, 7% were identified as AAPI (of whom 17% were identified as Chinese, 9% Asian Indian, 8% Pacific Islander, and 7% Vietnamese); 35% as Hispanic (of whom 15% were identified as Mexican and 1% Puerto Rican); and 59% as NHW. Mean [SD] age at hospitalization was lower in Asian Indian (60.4 [17.4] years), Pacific Islander (49.4 [16.7] years), and Mexican patients (57.4 [16.9] years), compared with NHW patients (66.9 [17.3] years, p<0.01). Mean age at death was lower in Mexican (67.7 [15.5] years) compared with NHW patients (75.5 [13.5] years, p<0.01). No differences in odds of mortality or MACE in AAPI or Hispanic patients relative to NHW patients were observed after adjustment for age.

CONCLUSIONS

Pacific Islander, Asian Indian, and Mexican patients hospitalized with COVID-19 in the AHA registry were significantly younger than NHW patients. COVID-19 infection leading to hospitalization may disproportionately burden some younger AAPI and Hispanic subgroups in the US.

Lipids and cardiovascular calcification: contributions to plaque vulnerability

PURPOSE OF REVIEW

Cardiovascular calcification, a common feature of atherosclerotic lesions, has long been known to associate with cardiovascular risk. The roles of lipoproteins in atherosclerosis are also established, and lipid-modifying therapies have shown capacity for plaque regression. However, the association of lipid-modifying therapies with calcification is more complex, and currently no medical therapies have been found to reverse or attenuate calcification in patients. In this review, we summarize recent developments in our understanding of the interplay between lipids and cardiovascular calcification, as well as new imaging modalities for assessing calcified atherosclerotic plaque vulnerability.

RECENT FINDINGS

Recent clinical studies have highlighted the associations of lipoprotein subtypes, such as low-density and high-density lipoprotein particles, as well as lipoprotein (a) [Lp(a)], with coronary calcification and calcific aortic valve disease. Further, evidence continues to emerge for the utility of fused 18F-sodium fluoride positron-emission tomographic and computed tomographic (18F-NaF PET/CT) imaging in characterizing the microarchitecture and vulnerability of atherosclerotic plaque, in both humans and animal models.

SUMMARY

The relationship between lipids and cardiovascular calcification is complex, and new imaging techniques, such as 18F-NaF PET/CT imaging, may allow for better identification of disease-modifying therapies and prediction of calcified plaque progression and stability to help guide clinical management.

Changes in microarchitecture of atherosclerotic calcification assessed by 18F-NaF PET and CT after a progressive exercise regimen in hyperlipidemic mice

BACKGROUND

Despite the association of physical activity with improved cardiovascular outcomes and the association of high coronary artery calcification (CAC) scores with poor prognosis, elite endurance athletes have increased CAC. Yet, they nevertheless have better cardiovascular survival. We hypothesized that exercise may transform vascular calcium deposits to a more stable morphology.

METHODS

To test this, hyperlipidemic mice (Apoe-/-) with baseline aortic calcification were separated into 2 groups (n = 9/group) with control mice allowed to move ad-lib while the exercise group underwent a progressive treadmill regimen for 9 weeks. All mice underwent blood collections and in vivo 18F-NaF μPET/μCT imaging both at the start and end of the exercise regimen. At euthanasia, aortic root specimens were obtained for histomorphometry.

RESULTS

Results showed that, while aortic calcification progressed similarly in both groups based on µCT, the fold change in 18F-NaF density was significantly less in the exercise group. Histomorphometric analysis of the aortic root calcium deposits showed that the exercised mice had a lower mineral surface area index than the control group. The exercise regimen also raised serum PTH levels twofold.

CONCLUSION

These findings suggest that weeks-long progressive exercise alters the microarchitecture of atherosclerotic calcium deposits by reducing mineral surface growth, potentially favoring plaque stability.

The Mechanobiology of Endothelial-to-Mesenchymal Transition in Cardiovascular Disease

Endothelial cells (ECs) lining the cardiovascular system are subjected to a highly dynamic microenvironment resulting from pulsatile pressure and circulating blood flow. Endothelial cells are remarkably sensitive to these forces, which are transduced to activate signaling pathways to maintain endothelial homeostasis and respond to changes in the environment. Aberrations in these biomechanical stresses, however, can trigger changes in endothelial cell phenotype and function. One process involved in this cellular plasticity is endothelial-to-mesenchymal transition (EndMT). As a result of EndMT, ECs lose cell-cell adhesion, alter their cytoskeletal organization, and gain increased migratory and invasive capabilities. EndMT has long been known to occur during cardiovascular development, but there is now a growing body of evidence also implicating it in many cardiovascular diseases (CVD), often associated with alterations in the cellular mechanical environment. In this review, we highlight the emerging role of shear stress, cyclic strain, matrix stiffness, and composition associated with EndMT in CVD. We first provide an overview of EndMT and context for how ECs sense, transduce, and respond to certain mechanical stimuli. We then describe the biomechanical features of EndMT and the role of mechanically driven EndMT in CVD. Finally, we indicate areas of open investigation to further elucidate the complexity of EndMT in the cardiovascular system. Understanding the mechanistic underpinnings of the mechanobiology of EndMT in CVD can provide insight into new opportunities for identification of novel diagnostic markers and therapeutic interventions.

Keeping immune checkpoint inhibitor myocarditis in check: advanced circulatory mechanical support as a bridge to recovery

Immune checkpoint inhibitor (ICI)‐associated myocarditis is a rare, potentially life‐threatening complication of immunotherapy. We report a case of a 60‐year‐old female with a history of colorectal cancer treated with nivolumab immunotherapy who presented with new cardiomyopathy complicated by cardiogenic shock and ventricular arrhythmias. Treatment of ICI‐associated myocarditis requires aggressive immunosuppression and supportive therapy. In this case, the patient required advanced mechanical circulatory support as a bridge to recovery. This case highlights the complexity of diagnosis, haemodynamic management, and treatment of fulminant ICI myocarditis.

Post-Acute COVID-19 Syndrome and the cardiovascular system: What is known?

Post-Acute COVID-19 Syndrome (PACS) is defined by persistent symptoms >3-4 weeks after onset of COVID-19. The mechanism of these persistent symptoms is distinct from acute COVID-19 although not completely understood despite the high incidence of PACS. Cardiovascular symptoms such as chest pain and palpitations commonly occur in PACS, but the underlying cause of symptoms is infrequently known. While autopsy studies have shown that the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rarely causes direct myocardial injury, several syndromes such as myocarditis, pericarditis, and Postural Orthostatic Tachycardia Syndrome have been implicated in PACS. Additionally, patients hospitalized with acute COVID-19 who display biomarker evidence of myocardial injury may have underlying coronary artery disease revealed by the physiological stress of SARS-CoV-2 infection and may benefit from medical optimization. We review what is known about PACS and the cardiovascular system and propose a framework for evaluation and management of related symptoms.

Optimizing Guideline-directed Medical Therapies for Heart Failure with Reduced Ejection Fraction During Hospitalization

Heart failure remains a huge societal concern despite medical advancement, with an annual direct cost of over $30 billion. While guideline-directed medical therapy (GDMT) is proven to reduce morbidity and mortality, many eligible patients with heart failure with reduced ejection fraction (HFrEF) are not receiving one or more of the recommended medications, often due to suboptimal initiation and titration in the outpatient setting. Hospitalization serves as a key point to initiate and titrate GDMT. Four evidence-based therapies have clinical benefit within 30 days of initiation and form a crucial foundation for HFrEF therapy: renin-angiotensin-aldosterone system inhibitors with or without a neprilysin inhibitor, β-blockers, mineralocorticoid-receptor-antagonists, and sodium-glucose cotransporter-2 inhibitors. The authors present a practical guide for the implementation of these four pillars of GDMT during a hospitalization for acute heart failure.

In Vivo Intravascular Pacing Using a Wireless Microscale Stimulator

Millions of patients worldwide are implanted with permanent pacemakers for the treatment of cardiac arrhythmias and conduction disorders. The increased use of these devices has established a growing clinical need to mitigate associated complications. Pacemaker leads, in particular, present the primary risks in most implants. While wireless power transfer holds great promise in eliminating implantable device leads, anatomical constraints limit efficient wireless transmission over the necessary operational range. We thereby developed a transmitter-centered control system for wireless power transfer with sufficient power for continuous cardiac pacing. Device safety was validated using a computational model of the system within an MRI-based anatomical model. The pacer was then fabricated to meet the acute constraints of the anterior cardiac vein (ACV) to enable intravascular deployment while maintaining power efficiency. Our computational model revealed the wireless system to operate at > 50 times below the tissue energy absorption safety criteria. We further demonstrated the capacity for ex vivo pacing of pig hearts at 60 beats per minute (BPM) and in vivo pacing at 120 BPM following pacer deployment in the ACV. This work thus established the capacity for wireless intravascular pacing with the potential to eliminate complications associated with current lead-based deep tissue implants.

Wearable Technology and Analytics as a Complementary Toolkit to Optimize Workload and to Reduce Injury Burden

Wearable sensors enable the real-time and non-invasive monitoring of biomechanical, physiological, or biochemical parameters pertinent to the performance of athletes. Sports medicine researchers compile datasets involving a multitude of parameters that can often be time consuming to analyze in order to create value in an expeditious and accurate manner. Machine learning and artificial intelligence models may aid in the clinical decision-making process for sports scientists, team physicians, and athletic trainers in translating the data acquired from wearable sensors to accurately and efficiently make decisions regarding the health, safety, and performance of athletes. This narrative review discusses the application of commercial sensors utilized by sports teams today and the emergence of descriptive analytics to monitor the internal and external workload, hydration status, sleep, cardiovascular health, and return-to-sport status of athletes. This review is written for those who are interested in the application of wearable sensor data and data science to enhance performance and reduce injury burden in athletes of all ages.

Asian-Americans and Pacific Islanders in COVID-19: Emerging Disparities Amid Discrimination

Coronavirus disease 2019 (COVID-19) is a global pandemic. In the USA, the burden of mortality and morbidity has fallen on minority populations. The understanding of the impact of this pandemic has been limited in Asian-Americans and Pacific Islanders (AAPIs), though disaggregated data suggest disproportionately high mortality rates. AAPIs are at high risk for COVID-19 transmission, in part due to their over-representation in the essential workforce, but also due to cultural factors, such as intergenerational residency, and other social determinants of health, including poverty and lack of health insurance. Some AAPI subgroups also report a high comorbidity burden, which may increase their susceptibility to more severe COVID-19 infection. Furthermore, AAPIs have encountered rising xenophobia and racism across the country, and we fear such discrimination only serves to exacerbate these rapidly emerging disparities in this community. We recommend interventions including disaggregation of mortality and morbidity data, investment in community-based healthcare, advocacy against discrimination and the use of non-inflammatory language, and a continued emphasis on underlying comorbidities, to ensure the protection of vulnerable communities and the navigation of this current crisis.

Heart transplantation in the early phase of the COVID-19 pandemic: A single-center case series

The infectious disease coronavirus disease 2019 (COVID‐19) was declared a pandemic by the World Health Organization in March 2020. The impact of COVID‐19 on solid organ transplantations, including heart transplantation, is currently unclear. Many transplant programs have been forced to swiftly re‐evaluate and adapt their practices, leading to a marked decrease in transplants performed. This trend has been due to various factors, including increased donor COVID‐19 screening scrutiny and recipient waiting list management in anticipation of COVID‐19 critical care surge capacity planning. In the face of these unknown variables, determining when and how to proceed with transplantation in our population of patients with end‐stage cardiomyopathies is challenging. Here, we describe our center's experience with orthotopic heart transplantation (OHT) in one of the country's pandemic epicenters, where we performed eight OHTs in the first 2 months after community spread began in late February 2020.

COVID-19 in a high-risk dual heart and kidney transplant recipient

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly infecting people worldwide, resulting in the infectious disease coronavirus disease 19 (COVID-19) that has been declared a pandemic. Much remains unknown about COVID-19, including its effects on solid organ transplant (SOT) recipients. Given their immunosuppressed state, SOT recipients are presumed to be at high risk of complications with viral infections such as SARS-CoV-2. Limited case reports in single SOT recipients, however, have not suggested a particularly severe course in this population. In this report, we present a dual-organ (heart/kidney) transplant recipient who was found to have COVID-19 and, despite the presence of a number of risk factors for poor outcomes, had a relatively mild clinical course.

Wearable Sensors for COVID-19: A Call to Action to Harness Our Digital Infrastructure for Remote Patient Monitoring and Virtual Assessments

The COVID-19 pandemic has brought into sharp focus the need to harness and leverage our digital infrastructure for remote patient monitoring. As current viral tests and vaccines are slow to emerge, we see a need for more robust disease detection and monitoring of individual and population health, which could be aided by wearable sensors. While the utility of this technology has been used to correlate physiological metrics to daily living and human performance, the translation of such technology toward predicting the incidence of COVID-19 remains a necessity. When used in conjunction with predictive platforms, users of wearable devices could be alerted when changes in their metrics match those associated with COVID-19. Anonymous data localized to regions such as neighborhoods or zip codes could provide public health officials and researchers a valuable tool to track and mitigate the spread of the virus, particularly during a second wave. Identifiable data, for example remote monitoring of cohorts (family, businesses, and facilities) associated with individuals diagnosed with COVID-19, can provide valuable data such as acceleration of transmission and symptom onset. This manuscript describes clinically relevant physiological metrics which can be measured from commercial devices today and highlights their role in tracking the health, stability, and recovery of COVID-19+ individuals and front-line workers. Our goal disseminating from this paper is to initiate a call to action among front-line workers and engineers toward developing digital health platforms for monitoring and managing this pandemic.

Heart Failure With Mid-range Ejection Fraction

PURPOSE OF REVIEW

To describe the epidemiology, pathophysiology, management, and prognosis of patients with heart failure with mid-range ejection fraction (HFmrEF).

RECENT FINDINGS

In 2013, The American Heart Association (AHA)/American College of Cardiology (ACC) assigned an ejection fraction (EF) range to heart failure with reduced ejection fraction (HFrEF, EF ≤ 40%) and heart failure with preserved ejection fraction (HFpEF, EF ≥50%). This classification created a "gray zone" of patients with EFs between 41% and 49% that ultimately came to be known as heart failure with borderline or mid-range ejection fraction. HFmrEF patients represent a group with heterogeneous clinical characteristics that at times resembles HFrEF, at others HFpEF, and at others still a unique phenotype altogether. No randomized controlled trials exist in those with HFmrEF, though HFrEF and HFpEF studies that include overlap suggest some potential benefit of beta blockers, angiotensin receptor blockers, mineralocorticoid receptor antagonists, and angiotensin receptor-neprilysin inhibitors. Mortality rates among the HFmrEF population are significant, and are similar to those in patients with HFrEF and HFpEF. HFmrEF is a complex disorder that remains poorly understood. Future research is needed to better elucidate the pathophysiology, management, and prognosis of this condition.

Steroid Hormone Vitamin D: Implications for Cardiovascular Disease

Understanding of vitamin D physiology is important because about half of the population is being diagnosed with deficiency and treated with supplements. Clinical guidelines were developed based on observational studies showing an association between low serum levels and increased cardiovascular risk. However, new randomized controlled trials have failed to confirm any cardiovascular benefit from supplementation in the general population. A major concern is that excess vitamin D is known to cause calcific vasculopathy and valvulopathy in animal models. For decades, administration of vitamin D has been used in rodents as a reliable experimental model of vascular calcification. Technically, vitamin D is a misnomer. It is not a true vitamin because it can be synthesized endogenously through ultraviolet exposure of the skin. It is a steroid hormone that comes in 3 forms that are sequential metabolites produced by hydroxylases. As a fat-soluble hormone, the vitamin D-hormone metabolites must have special mechanisms for delivery in the aqueous bloodstream. Importantly, endogenously synthesized forms are carried by a binding protein, whereas dietary forms are carried within lipoprotein particles. This may result in distinct biodistributions for sunlight-derived versus supplement-derived vitamin D hormones. Because the cardiovascular effects of vitamin D hormones are not straightforward, both toxic and beneficial effects may result from current recommendations.

Monomorphic Ventricular Arrhythmias in Athletes

Ventricular arrhythmias are challenging to manage in athletes with concern for an elevated risk of sudden cardiac death (SCD) during sports competition. Monomorphic ventricular arrhythmias (MMVA), while often benign in athletes with a structurally normal heart, are also associated with a unique subset of idiopathic and malignant substrates that must be clearly defined. A comprehensive evaluation for structural and/or electrical heart disease is required in order to exclude cardiac conditions that increase risk of SCD with exercise, such as hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. Unique issues for physicians who manage this population include navigating athletes through the decision of whether they can safely continue their chosen sport. In the absence of structural heart disease, therapies such as radiofrequency catheter ablation are very effective for certain arrhythmias and may allow for return to competitive sports participation. In this comprehensive review, we summarise the recommendations for evaluating and managing athletes with MMVA.

Contractile and hemodynamic forces coordinate Notch1b-mediated outflow tract valve formation

Biomechanical forces and endothelial-to-mesenchymal transition (EndoMT) are known to mediate valvulogenesis. However, the relative contributions of myocardial contractile and hemodynamic shear forces remain poorly understood. We integrated 4-D light-sheet imaging of transgenic zebrafish models with moving-domain computational fluid dynamics to determine effects of changes in contractile forces and fluid wall shear stress (WSS) on ventriculobulbar (VB) valve development. Augmentation of myocardial contractility with isoproterenol increased both WSS and Notch1b activity in the developing outflow tract (OFT) and resulted in VB valve hyperplasia. Increasing WSS in the OFT, achieved by increasing blood viscosity through EPO mRNA injection, also resulted in VB valve hyperplasia. Conversely, decreasing myocardial contractility by Tnnt2a morpholino oligonucleotide (MO) administration, 2,3-butanedione monoxime treatment, or Plcγ1 inhibition completely blocked VB valve formation, which could not be rescued by increasing WSS or activating Notch. Decreasing WSS in the OFT, achieved by slowing heart rate with metoprolol or reducing viscosity with Gata1a MO, did not affect VB valve formation. Immunofluorescent staining with the mesenchymal marker, DM-GRASP, revealed that biomechanical force-mediated Notch1b activity is implicated in EndoMT to modulate valve morphology. Altogether, increases in WSS result in Notch1b- EndoMT-mediated VB valve hyperplasia, whereas decreases in contractility result in reduced Notch1b activity, absence of EndoMT, and VB valve underdevelopment. Thus, we provide developmental mechanotransduction mechanisms underlying Notch1b-mediated EndoMT in the OFT.

Lipoproteins in Cardiovascular Calcification: Potential Targets and Challenges

Previously considered a degenerative process, cardiovascular calcification is now established as an active process that is regulated in several ways by lipids, phospholipids, and lipoproteins. These compounds serve many of the same functions in vascular and valvular calcification as they do in skeletal bone calcification. Hyperlipidemia leads to accumulation of lipoproteins in the subendothelial space of cardiovascular tissues, which leads to formation of mildly oxidized phospholipids, which are known bioactive factors in vascular cell calcification. One lipoprotein of particular interest is Lp(a), which showed genome-wide significance for the presence of aortic valve calcification and stenosis. It carries an important enzyme, autotaxin, which produces lysophosphatidic acid (LPA), and thus has a key role in inflammation among other functions. Matrix vesicles, extruded from the plasma membrane of cells, are the sites of initiation of mineral formation. Phosphatidylserine, a phospholipid in the membranes of matrix vesicles, is believed to complex with calcium and phosphate ions, creating a nidus for hydroxyapatite crystal formation in cardiovascular as well as in skeletal bone mineralization. This review focuses on the contributions of lipids, phospholipids, lipoproteins, and autotaxin in cardiovascular calcification, and discusses possible therapeutic targets.

Advanced microscopy to elucidate cardiovascular injury and regeneration: 4D light-sheet imaging

The advent of 4-dimensional (4D) light-sheet fluorescence microscopy (LSFM) has provided an entry point for rapid image acquisition to uncover real-time cardiovascular structure and function with high axial resolution and minimal photo-bleaching/-toxicity. We hereby review the fundamental principles of our LSFM system to investigate cardiovascular morphogenesis and regeneration after injury. LSFM enables us to reveal the micro-circulation of blood cells in the zebrafish embryo and assess cardiac ventricular remodeling in response to chemotherapy-induced injury using an automated segmentation approach. Next, we review two distinct mechanisms underlying zebrafish vascular regeneration following tail amputation. We elucidate the role of endothelial Notch signaling to restore vascular regeneration after exposure to the redox active ultrafine particles (UFP) in air pollutants. By manipulating the blood viscosity and subsequently, endothelial wall shear stress, we demonstrate the mechanism whereby hemodynamic shear forces impart both mechanical and metabolic effects to modulate vascular regeneration. Overall, the implementation of 4D LSFM allows for the elucidation of mechanisms governing cardiovascular injury and regeneration with high spatiotemporal resolution.

Multiscale light-sheet for rapid imaging of cardiopulmonary system

The ability to image tissue morphogenesis in real-time and in 3-dimensions (3-D) remains an optical challenge. The advent of light-sheet fluorescence microscopy (LSFM) has advanced developmental biology and tissue regeneration research. In this review, we introduce a LSFM system in which the illumination lens reshapes a thin light-sheet to rapidly scan across a sample of interest while the detection lens orthogonally collects the imaging data. This multiscale strategy provides deep-tissue penetration, high-spatiotemporal resolution, and minimal photobleaching and phototoxicity, allowing in vivo visualization of a variety of tissues and processes, ranging from developing hearts in live zebrafish embryos to ex vivo interrogation of the microarchitecture of optically cleared neonatal hearts. Here, we highlight multiple applications of LSFM and discuss several studies that have allowed better characterization of developmental and pathological processes in multiple models and tissues. These findings demonstrate the capacity of multiscale light-sheet imaging to uncover cardiovascular developmental and regenerative phenomena.