Coxiella burnetii infection of left atrial thrombus mimicking an atrial myxoma

Frenemies within: An Endocarditis Case in Behçet's Disease

A 57-year female patient diagnosed with Behçet's disease, on azathioprine, was noticed to have at a routine examination antinuclear and antiphospholipid antibodies. An overlapping lupus-like syndrome was diagnosed; hydroxychloroquine and aspirin were added. Three years later, the patient presented with dyspnea and sweating, with no fever. A cardiac bruit was noted; a giant vegetation was detected by echocardiography. Laboratory revealed severe thrombocytopenia, antiphospholipid antibodies and low complement. Blood cultures were positive for Abiotrophia defectiva serology and also revealed a chronic Coxiella burnetii infection. Antibiotic therapy, low-dose anticoagulation and control of the underlying disease mildly improved the platelet count, which fully recovered only after cardiac valve replacement. However, the Behçet's disease, initially quiescent, flared after the therapy of infections. We discuss potential links between Behçet's disease and the occurrence of antinuclear and antiphospholipid antibodies and Coxiella endocarditis in this setting. We also highlight the differences between the endocarditis in Behçet's disease, antiphospholipid syndrome, Coxiella burnetii and Abiotrophia defectiva infection, respectively. Intracellular infections may modify the presentation of autoimmune diseases. Confounding clinical features of Coxiella persistent infection and non-bacterial thrombotic endocarditis in Behçet's disease warrant further insight.

Gigantic Thrombus of the Left Atrium in Mitral Stenosis

Introduction

Excess dilatation of the left atrium >65 mm is known in the literature as gigantic atrium. This dilation is most commonly encountered in the mitral insufficiency of rheumatic etiology, but also in severe prolapses of the mitral valve, permanent atrial fibrillation, and at the left right shunt with cardiac insufficiency.

Case report

In this paper is presented a case study of echocardiographically verified giant thrombus in left atrium in a 50 years old female patient aged 50 hospitalized because of tiredness, choking, heartburn and urinary tract symptoms. The patient had rheumatic fever at age of 18 years. At age of 35, she was diagnosed with mitral stenosis. In permanent atrial fibrillation with anamnestic data on the previous cerebrovascular stroke (CVI) and the repeated transitional ischemic seizures. Echocardiographic examination confirmed severe mitral stenosis with moderate aortic insufficiency and gigantic left atrium (LA) with gigantic thrombus. Invasive diagnostics were indicated and performed, followed by an acute cardiac surgery including left atrial thrombectomy and implantation of the mechanical aortic and mitral valve. The surgical course was without complications.

Conclusion

On eleven postoperative day, after mobilization, the patient experiences stroke with motor aphasia. She was clinically recovering from stroke consequences, and remains cardiollogically stable.

From Q Fever to Coxiella burnetii Infection: a Paradigm Change

Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.