Cardiac paragangliomas are among the rarest primary cardiac tumors. We present a case of left atrial paraganglioma in a patient who presented with symptoms and signs of catecholamine excess in which cardiovascular magnetic resonance in multiple orientations and PET-CT played an important role in the diagnosis and tissue characterization.

Cystic adventitial disease (CAD) of the popliteal artery is a rare vascular disease of unknown etiology in which a mucin-containing cyst develops in the adventitial layer of the artery. We report the case of a 26-year-old male with CAD of the right popliteal artery diagnosed non-invasively with 3 Tesla cardiovascular magnetic resonance and confirmed on post-operative histopathology.

Background and Purpose: Unstable carotid plaques are a common cause of ischemic strokes. Identifying markers that reflect/contribute to plaque instability has become a prominent focus in cardiovascular research. The adipokines, resistin and chemerin, and ChemR23 (chemerin receptor), may play a role in carotid atherosclerosis, making them potential candidates to assess plaque instability. However, the expression and interrelationship of resistin and chemerin (and ChemR23) protein and mRNA within the carotid atherosclerotic plaque remains elusive. Thus, we investigated herein, the association between plaque mRNA and protein expression of resistin and chemerin (and ChemR23) and carotid plaque instability in humans, and whether sex differences exist in the relationship between these adipokines and plaque instability. Methods: Human carotid plaques were processed for immunohistochemical/mRNA analysis of resistin, chemerin, and ChemR23. Plaque instability was assessed by gold-standard histological classifications. A semi-quantitative scoring system was used to determine the intensity of adipokine expression on macrophages/foam cells, as well as the percentage of inflammatory cells stained positive. Plaque adipokine protein expression was also digitally quantified and mRNA expression was assessed by qRT-PCR. Results: Resistin and chemerin mRNA expression was 80% and 32% lower, respectively, in unstable versus stable plaques ( P <0.05), while no difference in ChemR23 mRNA expression was observed. In contrast, greater resistin staining intensity and percentage of cells stained positive were detected in unstable versus stable plaques ( P <0.01). Similarly, chemerin and ChemR23 staining intensity and percentage of cells stained were positively associated with plaque instability ( P <0.05). No strong sex-specific relationship was observed between adipokines and plaque instability. Conclusions: This study examined the relationship between resistin, chemerin, and ChemR23, and carotid plaque instability, with a specific analysis at the plaque level. We reported a positive association between plaque instability and protein levels of resistin, chemerin, and ChemR23 but a negative association with resistin and chemerin mRNA expression. This suggests these adipokines exert proinflammatory roles in the process of carotid atherosclerosis and may be regulated via a negative feedback regulatory mechanism.

Objectives Despite the clear benefits of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in mitigating the impact of the coronavirus disease 2019 pandemic, there are emerging reports of postvaccination myocarditis, the majority of which are diagnosed based on the clinical and radiologic findings without biopsy confirmation. We report a case of biopsy-confirmed lymphohistiocytic myocarditis after Moderna mRNA-1273 vaccination. Methods We describe a case of a previously healthy 45-year-old woman who had palpitations, exercise intolerance, and syncope 1 week after her first mRNA-1273 vaccine dose. Laboratory tests and cardiac imaging were compatible with myocarditis. Given her unusual clinical presentation, an endomyocardial biopsy was performed to exclude other potential etiologies. Results The endomyocardial biopsy specimen showed patchy endocardial and intramyocardial lymphohistiocytic infiltrates with scattered eosinophils and focal myocyte injury. CD3 and CD68 immunostains confirmed the lymphocytic and histiocytic nature of the infiltrate, respectively. A focal histiocytic collection suggestive of an ill-defined granuloma was present. The histologic and immunohistochemical findings of a lymphohistiocytic myocarditis were highly suggestive of a postvaccination hypersensitivity reaction. Conclusions Myocarditis following SARS-CoV-2 vaccination is a rare adverse event. The findings of a lymphohistiocytic myocarditis with scattered eosinophils and a possible ill-defined granuloma are highly suggestive of a hypersensitivity reaction. The mechanism by which this inflammation occurs remains uncertain. Despite our findings, the benefits of SARS-CoV-2 vaccination far outweigh the risks.

Through the ongoing and heightening coronavirus disease 2019 (COVID-19) pandemic, the heart has been implicated as a central target of injury associated with significantly increased morbidity and mortality. Correspondingly, heart transplant recipients are a vulnerable population for which insufficient research has been conducted. Pathologic antibody-mediated rejection (pAMR) of cardiac allografts shares many characteristics with COVID-19-associated cardiac injury. In this case study, we investigate a 57-year-old female who contracted COVID-19 11 days postheart transplant and was observed to have pAMR while positive for laboratory-confirmed COVID-19, resulting in a diagnostic conundrum.

Diffuse intimal thickening (DIT) is a pre-clinical stage of atherosclerosis characterized by thickened intima. The molecular basis of its susceptibility to atherogenesis is unknown, and mechanistic investigations cannot be performed in commonly used mouse models, in which DIT does not exist. Vascular smooth muscle cells (SMCs) are the predominant cell type that occupies the intima and media of DIT. The molecular differences between these two layers may reveal the earliest phenotypic changes in SMCs to promote atherosclerosis. We benchmarked the RNA quality of human coronary arteries from autopsies (n = 7) and explanted hearts (n = 7) and performed Visium spatial gene expression on tissue sections with DIT. Although autopsy samples met the RNA quality standard for Visium (DV200 ≥ 30%), only arteries from explanted hearts exhibited reliable sequencing performance. Genes enriched in TGF-β-mediated remodeling of the extracellular matrix were overrepresented in the intima. SMCs enriched in the intima are dedifferentiated, but unlike those in the atherosclerotic lesions, they are not pro-inflammatory. Our findings indicate that autopsy samples are not ideal to distinguish subtle differences among cell phenotypes. SMCs in thickened intima may lead to lipid retention but not necessarily the onset of atherosclerosis.