Kikuchi-Fujimoto Disease: A Case of SARS-CoV-2 Infection Triggering the Rare Disease.

Kikuchi-Fujimoto disease (KFD), or histiocytic necrotizing lymphadenitis, is a rare, benign, and self-limited disease caused by subacute necrotizing regional lymphadenopathy. The etiology is unknown, although virus and autoimmune mechanisms have been proposed. Patients develop enlarged lymph nodes, fever, and, less frequently, extranodal signs. No specific laboratory test contributes to the diagnosis, and lymph node biopsy is the gold standard to define the diagnosis. The treatment is generally with supportive therapy and usually is spontaneously resolved within six months.  In this article, the authors present the case of a 41-year-old female with mild SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection 10 weeks before she was admitted to the emergency department (ED) due to cervical lymphadenopathies and fever lasting over three weeks. Physical examination revealed multiple lymphadenopathies on the submandibular and jugular regions, cutaneous rash, and hepatosplenomegaly. Blood tests showed elevated acute phase proteins, thrombocytopenia, and increased transaminases and lactate dehydrogenase (LDH). Computed tomography (CT) of the neck showed multiple adenopathies at levels I, II, III, and IV according to the Classification for Lymph Nodes from the American Head and Neck Society and American Academy of Otolaryngology on the right side. Excision biopsy was performed and histopathological examination confirmed KFD. A comprehensive analysis performed was unrevealing of an infectious or autoimmune cause and was assumed to be most likely triggered by SARS-CoV-2 infection given the timeframe correlation. KFD diagnosis is challenging and there are few reported cases of association with SARS-CoV-2 in the literature. Although further investigation is still needed to better understand the relation between them, it is important that physicians take SARS-CoV-2 infection and vaccination into consideration in KFD's differential diagnosis.

Q Fever: An Emerging Reality in Portugal.

Q fever is a zoonosis caused by Coxiella burnetii with worldwide distribution at the increasing expression in Europe and endemic in Portugal. It is transmitted by inhalation of aerosols containing spores, main reservoir being cattle, goats and sheep as by ingesting cottage cheese or unpasteurized milk. The majority of patients are asymptomatic; however, they may present with fever, atypical pneumonia, acute hepatitis, cutaneous manifestations and rarely with cardiac or neurological involvement. Although most cases are self-limited, focal persistent or chronic Q fever can manifest years after the onset, wherefore follow-up is essential. The clinical heterogeneity may be so variable that the disease is often diagnosed only if it has been systematically considered. It should be especially taken into account in the presence of risk factors as valvular or joint prostheses, immunocompromised patients, pregnant women and epidemiological setting. The authors present a rare case of Coxiella burnetii pneumonia with cutaneous and hepatic manifestations without any risk factor. This case aims to emphasize the importance of Q fever in the differential diagnosis of fever or atypical pneumonia, even in the absence of known risk factors. The diagnosis is often challenging for clinicians and it is necessary to maintain a high index of suspicion. In Europe and specifically in Portugal is mandatory to report the cases to establish the real impact of this disease.

Good agreement between echocardiography and impedance cardiography in the assessment of left ventricular performance in hypertensive patients.

BACKGROUND: Impedance cardiography (ICG) is a noninvasive hemodynamic monitoring tool which can define hypertensive patients' hemodynamic profiles and help to tailor antihypertensive therapy. This study assesses the concordance between ICG-derived indexes used to evaluate left ventricular performance and transthoracic echocardiography (TTE) in hypertensive patients. METHODS: In this IMPEDDANS post-hoc analysis, the ICG-derived indexes are compared with TTE by Bland-Altman method. Statistical significance of the relationship between the values obtained was assessed by generalized linear mixed-effects models. RESULTS: In supine position, Bland-Altman analysis showed good concordance for cardiac output (CO) (mean difference of 0.006 mL/min [-0.120; 0.133]), cardiac index (CI) (mean difference of 0.016 mL/min/m2 [-0.471; 0.504]), pre-ejection period (PEP) (mean difference of -0.216 ms [-4.510; 4.077]), left ventricular ejection time (LVET) (mean difference of -0.140 ms [-6.573; 6.293]), and systolic time ratio (STR) (mean difference of -0.00004 [-0.008; 0.008]). In orthostatic position, good concordance was found for CO (mean difference 0.028 mL/min [-2.036; 1.980]), CI (mean difference -0.012 mL/min/m2 [-1.063; 1.039]), and STR (mean difference -0.101 [0.296; 0.094]). No significant difference between methods was identified by the linear mixed-effects models. CONCLUSION: The ICG-derived indexes CO, CI, PEP, LVET, and STR in supine position have good agreement with TTE. Therefore, ICG can be used to accurately evaluate left ventricular performance.

Systolic time ratio measured by impedance cardiography accurately screens left ventricular diastolic dysfunction in patients with arterial hypertension.

BACKGROUND: The use of impedance cardiography (ICG) may play a role in the assessment of cardiac effects of hypertension (HT), especially its hemodynamic features. Hypertensive heart disease involves structural changes and alterations in left ventricular geometry that end up causing systolic and/or diastolic dysfunction. The IMPEDDANS study aims to assess the usefulness of ICG for the screening of left ventricular diastolic dysfunction (LVDD) in patients with HT. METHODS: Patients with HT were assessed by echocardiography and ICG. Receiver-operating characteristic curve and the area under the curve were used to assess the discriminative ability of the parameters obtained by ICG to identify LVDD, as diagnosed by echocardiography. RESULTS: ICG derived pre-ejection period (PEP), left ventricle ejection time (LVET), systolic time ratio (STR) and D wave were associated (p < 0.001) with LVDD diagnosis, with good discriminative ability: PEP (AUC 0.81; 95% CI 0.74-0.89), LVET (AUC 0.82; 95% CI 0.75-0.88), STR (AUC 0.97; 95% CI 0.94-1.00) and presence of D wave (AUC = 0.87; 95% CI 0.82-0.93). STR ≥ 0.30 outperformed the other parameters (sensitivity of 98.0%, specificity of 90.2%, positive predictive value of 95.2%, and negative predictive value of 96.1%). CONCLUSION: The ICG derived value of STR allows the accurate screening of LVDD in patients with HT. It might as well be used for follow up assessment. TRIAL REGISTRATION: The study protocol was retrospectively registered as IMPEDDANS on ClinicalTrials.gov (ID: NCT03209141) on July 6, 2017.