We conducted a meta‐analysis to synthesize the best available evidence comparing cardiac biventricular structure and function using cardiac magnetic resonance imaging (CMR) and transthoracic ...echocardiography (TTE) in elite female athletes and healthy controls (HC). Chronic exposure to exercise may induce cardiac chamber enlargement as a means to augment stroke volume, a condition known as the “athlete's heart.” These changes have not been clearly characterized in female athletes. Multiple databases were searched from inception to June 18, 2019. Outcomes of interest included left ventricular (LV) and right ventricular (RV) dimensional, volumetric, mass, and functional assessments in female athletes. Most values were indexed to body surface area. The final search yielded 22 studies, including 1000 female athletes from endurance, strength, and mixed athletic disciplines. CMR‐derived LV end‐diastolic volume (LVEDV) and RV end‐diastolic volume (RVEDV) were greater in endurance athletes (EA) versus HC (17.0% and 18.5%, respectively; both p < 0.001). Similarly, TTE‐derived LVEDV and RVEDV were greater in EA versus HC (16.8% and 28.0%, respectively; both p < 0.001). Both LVEF and RVEF were lower in EA versus HC, with the most pronounced difference observed in RVEF via TTE (9%) (p < 0.001). LV stroke volume was greater in EA versus HC via both CMR (18.5%) and TTE (13.2%) (both p < 0.05). Few studies reported data for the mixed athlete (MA) population and even fewer studies reported data for strength athletes (SA), therefore a limited analysis was performed on MA and no analysis was performed on SA. This evidence‐synthesis review demonstrates the RV may be more susceptible to ventricular enlargement. General changes in LV and RV structure and function in female EA mirrored changes observed in male counterparts. Further studies are needed to determine if potential adverse outcomes occur secondary to these changes.
This article focuses on the morphological and physiological effects of endurance‐based exercise on the female heart. Much literature has been described in males, but this data features data that mirrors that of men and particularly focuses on left and right ventricular function using established and advanced imaging modalities.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This work presents an in-depth numerical investigation into a hypothesized two-layer central pattern generator (CPG) that controls mammalian walking and how different parameter choices might affect ...the stepping of a simulated neuromechanical model. Particular attention is paid to the functional role of features that have not received a great deal of attention in previous work: the weak cross-excitatory connectivity within the rhythm generator and the synapse strength between the two layers. Sensitivity evaluations of deafferented CPG models and the combined neuromechanical model are performed. Locomotion frequency is increased in two different ways for both models to investigate whether the model's stability can be predicted by trends in the CPG's phase response curves (PRCs). Our results show that the weak cross-excitatory connection can make the CPG more sensitive to perturbations and that increasing the synaptic strength between the two layers results in a trade-off between forced phase locking and the amount of phase delay that can exist between the two layers. Additionally, although the models exhibit these differences in behavior when disconnected from the biomechanical model, these differences seem to disappear with the full neuromechanical model and result in similar behavior despite a variety of parameter combinations. This indicates that the neural variables do not have to be fixed precisely for stable walking; the biomechanical entrainment and sensory feedback may cancel out the strengths of excitatory connectivity in the neural circuit and play a critical role in shaping locomotor behavior. Our results support the importance of including biomechanical models in the development of computational neuroscience models that control mammalian locomotion.
Animal locomotion is influenced by a combination of constituent joint torques (e.g., due to limb inertia and passive viscoelasticity), which determine the necessary muscular response to move the ...limb. Across animal size-scales, the relative contributions of these constituent joint torques affect the muscular response in different ways. We used a multi-muscle biomechanical model to analyze how passive torque components change due to an animal's size-scale during locomotion. By changing the size-scale of the model, we characterized emergent muscular responses at the hip as a result of the changing constituent torque profile. Specifically, we found that activation phases between extensor and flexor torques to be opposite between small and large sizes for the same kinematic motion. These results suggest general principles of how animal size affects neural control strategies. Our modeled torque profiles show a strong agreement with documented hindlimb torque during locomotion and can provide insights into the neural organization and muscle activation behavior of animals whose motion has not been extensively documented.
Spontaneous pneumomediastinum with concurrent pneumorrhachis (air in the spinal canal) and subcutaneous emphysema can be an alarming presentation, both clinically and radiographically. These clinical ...entities often require only conservative measures after ruling out any worrisome underlying causes. Management often involves appropriate imaging, hospital admission, and sub-specialty consultation as needed to help determine any potential causes for the presentation that may require anything more than a period of medical observation.
A 20-year-old man presented to the Emergency Department (ED) with acute onset of chest pain. Physical examination was significant for subcutaneous emphysema across the anterior chest wall. Radiographs of the neck revealed extensive soft tissue emphysema extending into the upper mediastinum. Computed tomography (CT) of the neck with contrast revealed a small amount of air within the central canal of the spinal cord, in addition to extensive pneumomediastinum and subcutaneous emphysema. The patient remained stable and was discharged home on hospital day 2, after significant threats for morbidity or mortality were ruled out.
Spontaneous pneumomediastinum, pneumorrhachis, and subcutaneous emphysema are rare clinical entities, but each requires thorough investigation in the ED to rule out any underlying life-threatening cause. A conservative treatment approach is appropriate for most patients without evidence of cardiorespiratory compromise or neurologic deficits accruing due to these problems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Acute immune-mediated polyneuropathies are a group of illnesses that cause paralysis following an infection. We describe a case of one of these illnesses being caused by the respiratory syncytial ...virus (RSV). An 81-year-old female was admitted for an RSV infection. She went into respiratory failure requiring intubation and mechanical ventilation and treatment with ribavirin. When she was extubated, she had bilateral lower extremity weakness and absent reflexes. Her disease progressed rapidly to involve her diaphragm, and eventually, the family agreed to let the natural death process occur. Our case is the first reported case in which an acute immune-mediated polyneuropathy was caused from an RSV infection.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
Aims
Current non-invasive screening methods for cardiac allograft rejection have shown limited discrimination and are yet to be broadly integrated into heart transplant care. Given ...electrocardiogram (ECG) changes have been reported with severe cardiac allograft rejection, this study aimed to develop a deep-learning model, a form of artificial intelligence, to detect allograft rejection using the 12-lead ECG (AI-ECG).
Methods and results
Heart transplant recipients were identified across three Mayo Clinic sites between 1998 and 2021. Twelve-lead digital ECG data and endomyocardial biopsy results were extracted from medical records. Allograft rejection was defined as moderate or severe acute cellular rejection (ACR) based on International Society for Heart and Lung Transplantation guidelines. The extracted data (7590 unique ECG-biopsy pairs, belonging to 1427 patients) was partitioned into training (80%), validation (10%), and test sets (10%) such that each patient was included in only one partition. Model performance metrics were based on the test set (n = 140 patients; 758 ECG-biopsy pairs). The AI-ECG detected ACR with an area under the receiver operating curve (AUC) of 0.84 95% confidence interval (CI): 0.78–0.90 and 95% (19/20; 95% CI: 75–100%) sensitivity. A prospective proof-of-concept screening study (n = 56; 97 ECG-biopsy pairs) showed the AI-ECG detected ACR with AUC = 0.78 (95% CI: 0.61–0.96) and 100% (2/2; 95% CI: 16–100%) sensitivity.
Conclusion
An AI-ECG model is effective for detection of moderate-to-severe ACR in heart transplant recipients. Our findings could improve transplant care by providing a rapid, non-invasive, and potentially remote screening option for cardiac allograft function.
Graphical Abstract
Graphical abstract
An artificial intelligence enabled ECG can effectively detect cardiac allograft rejection among heart transplant recipients. AI, artificial intelligence; AUC, area under the receiver operating characteristic curve; ECG, electrocardiogram; ISHLT, International Society for Heart and Lung Transplantation; NPV, negative predictive value; PPV, positive predictive value.
BACKGROUND Systemic lupus erythematosus (SLE) causes sight-threatening, ophthalmologic problems that are frequently challenging to manage. Optic neuropathy is a rare ophthalmological complication of ...SLE that can progress to total bilateral vision loss if not identified and treated rapidly. We describe a patient with SLE who presented with an acute, painless unilateral optic neuropathy who subsequently experienced partial recovery of vision when treated with high-dose intravenous corticosteroids. CASE REPORT A 44-year-old female with known SLE presented with 4 days of painless, complete, and gradual vision loss in the right eye. Initial ophthalmologic examination revealed no light perception, afferent pupil defect, 4+ optic disc swelling, and 1+ venous tortuosity of the right eye. No hemorrhage or exudates were noted. Diagnostic workup revealed a lupus flare with elevated inflammatory markers including elevated anti-nuclear antibody, anti-ds-DNA antibody, anti-Sm antibody, and anti-phospholipid IgG antibody. The diagnosis of optic neuropathy was clinically established, and the patient was treated with high-dose intravenous corticosteroids. Her vision improved, and she was transitioned to oral corticosteroids with eventual significant improvement in her vision. CONCLUSIONS Optic neuropathy is a rare and devastating ophthalmologic complication of SLE. The diagnosis can be made by linking key clinical findings on ophthalmologic examination with positive serological studies. If treated rapidly with immunosuppressive therapy, the vision loss can be reversed, and permanent blindness avoided. Although this rare complication is generally bilateral in nature, clinician must also be aware of unilateral disease and treat patients accordingly.
Abstract
Diffuse alveolar hemorrhage (DAH) is a rare, but potentially fatal, complication of antiphospholipid syndrome, and may present with acute and fulminant symptoms. We report a case of DAH ...presenting as sudden onset dyspnea in a gentleman with known antiphospholipid syndrome. Chest computed tomography angiography with pulmonary embolism protocol showed right lower lobe segmental filling defects, upper-lobe predominant diffuse ground-glass opacities, and centrilobular nodules bilaterally. The presence of DAH can be confirmed by bronchoalveolar lavage with serial aliquots, but this procedure typically does not elucidate the specific etiology for the hemorrhage. The treatment for patients with severe disease typically consists of a combination of immunosuppressive medications in the form of high-dose intravenous glucocorticoids plus rituximab, cyclophosphamide or mycophenolate; and/or plasma exchange. This case both provides an example of high-quality diagnostic imaging of diffuse alveolar hemorrhage as well as demonstrates the clinical and image-based improvement after treatment.
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