Gram-positive cocci species, notably Staphylococcus, Streptococcus, and Enterococcus account for 80 to 90% of infective endocarditis cases. HACEK microorganisms (Haemophilus spp., Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae) account for approximately 3% of cases and Candida species account for 1-2% of cases. Micrococcus luteus is a rare cause of endocarditis. To our knowledge, only 17 cases of prosthetic valve endocarditis have been described due to M. luteus and a single case of native aortic valve endocarditis has been described. The following case is the only documented case of native mitral valve endocarditis. A review of the literature pertaining to Micrococcus endocarditis was performed to further characterize the entity.

Pembrolizumab is a monoclonal antibody directed towards programmed cell death protein 1 (PD-1) and is an antineoplastic drug which has a growing variety of oncologic uses. Pembrolizumab is commonly associated with immune-related adverse events (IRAEs) but is infrequently noted to cause cardiotoxicities such as myocarditis, arrhythmias, and heart failure. The following case report illustrates the clinical course of a 67-year-old female patient with stage IV non-small-cell lung cancer who developed Mobitz type 2 second-degree atrioventricular block three weeks after receiving her first infusion of pembrolizumab. Within a few hours of presentation, she progressed to symptomatic complete heart block requiring emergent placement of a temporary transvenous pacemaker. The article further discusses proposed mechanisms to explain IRAEs and management of IRAEs. We conclude by recommending a higher degree of caution and awareness among all physicians when treating patients on immunotherapy and a multidisciplinary approach when considering resumption of immune checkpoint inhibitor therapy.

Manganese accumulation in the central nervous system creates clinical symptoms of cognitive dysfunction, behavioral changes, and movement disorders resembling Parkinson’s disease. Radiographic features of this rare clinical entity include symmetric T1 hyperintensities in the bilateral globus pallidi, with corresponding hypointensities on T2-weighted images. Total parenteral nutrition (TPN) is an increasingly used potentially lifesaving therapy for patients who cannot tolerate enteral nutrition. However, when used over a period of several weeks to months, its associated risks and complications carry significant morbidity and mortality. One of the more rare complications of TPN use is manganese toxicity. We provided care for a 38-year-old female on chronic TPN who presented to the hospital with Parkinsonian features, confusion, falls, and lethargy. MRI brain showed T1 hyperintensities in the bilateral globus pallidi, which were attributed to manganese toxicity from chronic TPN use. Supporting evidence for this rare entity included decreased signal intensity in the bilateral globus pallidi on T2-weighted images and T1 hyperintensities in the substantia nigra. With antifungal treatment and permanent cessation of TPN, her mentation and neurological symptoms began to improve within a week. Repeat MRI brain performed one month after discontinuation of TPN revealed improvement of the T1 hyperintensities in the bilateral globus pallidi. Our objective in presenting this case is to highlight manganese neurotoxicity as a rare complication of TPN in a patient without known hepatic dysfunction and to emphasize the importance of routinely monitoring patients for the possible adverse effects of chronic TPN. Our case is among the handful of published cases in which a patient without known liver dysfunction, which is the primary organ responsible for manganese elimination from the body, developed manganese neurotoxicity.

Coronary arteries arising from the pulmonary artery have an incidence of 0.002% in the general population. We present a 29-year-old woman who presented to our hospital with acute decompensated heart failure and atrial fibrillation with a rapid ventricular rate. She underwent a cardiac catheterization to rule out ischemic disease, which revealed retrograde contrast flow through the left coronary artery from the right coronary artery. A coronary computed tomography (CT) angiogram was pursued which showed the presence of an anomalous left coronary artery arising from the pulmonary artery (ALCAPA). For the management of her atrial fibrillation, she was electrically cardioverted. She was discharged on guideline-directed medical therapy for her heart failure, with a cardiac surgery referral for the surgical fixation of her ALCAPA.