Mediastinitis secondary to invasive infection by group A Streptococcus in Spain.

This study describes 5 mediastinitis cases secondary to invasive group A Streptococcus (iGAS) disease in a recent outbreak in Spain. Among 398 iGAS cases between January 2019-March 2023, 5 (1.3%) were mediastinitis, 4 occurring in December 2022, all secondary to pneumonia or deep neck infection. We outline the clinical outcome with a review of the scarce pediatric literature.  Conclusion: mediastinistis is a rare but severe complication of iGAS and a high level of suspicion is required to diagnose it. What is Known: • Group A Streptococcus can cause invasive and severe infections in children. • Mediastinitis is a severe complication from some bacterial infections, mainly secondary due to deep-neck abscesses. What is New: • Mediastinitis is an unrecognized complication due to an invasive group A Streptococcus (iGAS) infection. • In cases of a deep-neck abscess or complicated pneumonia a high clinical suspicion of iGAS mediastinitis is required, especially when the clinical course is not favorable.

Effect of Different Therapeutic Strategies on Olfactory Outcomes in Patients With Chronic Rhinosinusitis With Nasal Polyps: A Systematic Review.

INTRODUCTION: Olfactory impairment is one of the cardinal symptoms of chronic rhinosinusitis with nasal polyps (CRSwNP). However, the effect of currently available therapeutic options on the recovery of the sense of smell is not well defined. The aim of this systematic review was to compile evidence on the impact of medical, surgical, and biological treatment on olfactory outcomes in patients with CRSwNP. METHODS: This review was conducted by 2 reviewers according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The quality of evidence of all the studies included in the qualitative synthesis was evaluated using the Critical Appraisal Skills Programme (CASP). RESULTS: Forty-four studies were included in the qualitative synthesis. These assessed sinonasal surgery (n=23), biologics (n=15), and conventional medical treatment (n=6). The methodological quality was moderate-to-high in most. Overall, significant improvements in the sense of smell were detected with all the interventions analyzed and measured using an objective tool, a subjective tool, or both. However, most studies used different outcome measures, thus hindering comparisons between interventions, and data on clinically relevant changes were missing. CONCLUSION: Oral corticosteroids, biologics, and sinonasal surgery improve the olfactory impairment associated with CRSwNP. However, the heterogeneous nature of existing studies does not allow accurate comparisons.

Skin lesions by Scedosporium apiospermum and Nocardia pulmonary infection in an oncologic patient: a case report.

BACKGROUND: Fungal infections, other than candidiasis and aspergillosis, are an uncommon entity. Despite this, emerging pathogens are a growing threat. In the following case report, we present the case of an immunocompromised patient suffering from two serious opportunistic infections in the same episode: the first of these, Nocardia multilobar pneumonia; and the second, skin infection by Scedosporium apiospermum. These required prolonged antibacterial and antifungal treatment. CASE PRESENTATION: This case is a 71-year-old oncological patient admitted for recurrent pneumonias that was diagnosed for Nocardia pulmonary infection. Nervous system involvement was discarded and cotrimoxazole was started. Haemorrhagic skin ulcers in the lower limbs appeared after two weeks of hospital admission. We collected samples which were positive for Scedosporium apiospermum and we added voriconazole to the treatment. As a local complication, the patient presented a deep bruise that needed debridement. We completed 4 weeks of intravenous treatment with slow improvement and continued with oral treatment until the disappearance of the lesions occurs. CONCLUSIONS: Opportunistic infections are a rising entity as the number of immunocompromised patients is growing due to more use of immunosuppressive therapies and transplants. Clinicians must have a high suspicion to diagnose and treat them. A fluid collaboration with Microbiology is necessary as antimicrobial resistance is frequent.

Sewage sludge composting under semi-permeable film at full-scale: Evaluation of odour emissions and relationships between microbiological activities and physico-chemical variables.

In the present study, physico-chemical characteristics, heavy metals content, odour emissions, microbial enumeration and enzymatic activities were analysed during industrial scale composting of sewage sludge partially pre-treated to evaluate the effect of a combined system of semi-permeable film and aeration on these parameters. The results related to physico-chemical parameters showed a decrease in total organic carbon (TOC), organic matter (OM), total carbon (TC) along the process. Volatile solids (VS) were also reduced, reaching 36% at 120 days, which is above the limit according to the current legislation. Similarly, metal content was found to be an important variable in the evolution of enzymatic activity, while lead (Pb), zinc (Zn), and nickel (Ni) were the most influential. Moreover, heavy metals were found below the limit of type B compost quality or European class 2 at the end of the process, which is suitable for agriculture soil. The odorous impact generated during the hydrolytic stage was reduced to an average value of 4 ouE/s. This suggests that, covered stage with the semi-permeable film, could be a viable solution to mitigate odour emissions. The highest temperature was reached at 10 days and it was favoured by semi-permeable film. Temperature promoted the presence of thermophilic bacteria and fungi and indicated an early biodegradation process mediated by microorganisms. Statistical analyses revealed a high correlation of physico-chemical variables with microbial activity. Thus, samples from the first 14 days were highly correlated with enzymatic activities such as ß-glucosidase (Ac-ßGlu), protease (Ac-Pr), and dehydrogenase (Ac-De), which have usually been involved in the hydrolysis of organic matter.

Septic pulmonary emboli detected by 18F-FDG PET/CT in children with S. aureus catheter-related bacteremia.

PURPOSE: The role of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) in the diagnosis of metastatic infectious foci in children with catheter-related blood stream infection has been hardly studied, although some authors have reported it benefit in the screening of metastatic foci in adult population. Septic pulmonary emboli are among the most difficult to identify, because many cases do not present pulmonary complaints or abnormal chest radiography. However, diagnosis of these foci has important therapeutic consequences. The purpose of this article is to describe the role of 18F-FDG PET/CT in the diagnosis of septic pulmonary embolism in children with S. aureus catheter-related bacteremia. METHODS: We report 3 children with S. aureus catheter-related bacteremia and normal chest X-ray at admission, in whom 18F-FDG PET/CT led to the diagnosis of unsuspected septic pulmonary emboli, with an impact on clinical management. RESULTS: All patients had hemophilia and implantable venous access ports and presented with fever and normal lung auscultation. Only 1 reported non-specific symptoms (undifferentiated left chest pain). All patients had normal chest X-ray on admission. Catheters were removed within 48 h after admission in 2 cases, and 5 days after admission in the last case, subsiding fever. In 2 children, paired blood cultures were not able to identify bacteremia. However, in all cases catheter tip and subcutaneous port cultures yielded S. aureus and PET/CT detected unsuspected pulmonary metastatic emboli. CONCLUSIONS: 18F-FDG PET/CT should be considered as a useful tool to diagnose septic pulmonary embolism in S. aureus catheter-related bacteremia, especially if conventional diagnostic imaging techniques have failed to reveal possible metastatic foci. Further studies are needed to clarify the usefulness of PET/CT performance in children with CRBSI.

Epidemiological factors related to hospitalization due to influenza in children below 6 months of age.

The aim of this study was to address the epidemiological factors associated to hospital admissions due to influenza in infants younger than 6 months. A case-control study was performed in a tertiary hospital in Spain. Cases were infants under 6 months of age without comorbidities who were admitted due to influenza between October 2010 and March 2015. Controls were healthy infants younger than 6 months who were hospitalized due to non-respiratory illness or non-infectious diseases (urinary tract infection was included as controls). Data were retrospectively collected from medical records and phone interviews. A total of 88 cases and 122 controls we included. From univariate analysis, differences were found in relation to maternal age (43.1 ± 4.95 vs 32 ± 5.3), paternal age (37 ± 6.4 vs 34.5 ± 6.1), having siblings (79 vs 24%), siblings below 4 years old (54 vs 15%), and having vaccinated grandparents (18 vs 39%) (p < 0.05). After logistic regression, having vaccinated grandparents was an independent protective factor (OR 0.22 [CI95%; 0.05-0.91]), while having siblings was a risk factor (OR 15.8 [CI95% 3.15-79.5]). Vaccination during pregnancy was highly uncommon (3.5 vs 8.3%; p = 0.3). CONCLUSION: This study underlines the importance of increasing influenza immunization among household contacts of infants below 6 months to prevent their influenza admission. What is Known: • Infants younger than 6 months old are considered a high-risk population. • Vaccination against influenza is not licensed in infants below 6 months. What is New: • Increasing vaccination coverage in elderly people could reduce infants' hospitalization rates. • Cocoon immunization strategy may reduce the admission of infants.

Prevention of acute kidney injury in Intensive Care Units.

Acute kidney injury (AKI) is a growing concern in Intensive Care Units. The advanced age of our patients, with the increase in associated morbidity and the complexity of the treatments provided favor the development of AKI. Since no effective treatment for AKI is available, all efforts are aimed at prevention and early detection of the disorder in order to establish secondary preventive measures to impede AKI progression. In critical patients, the most frequent causes are sepsis and situations that result in renal hypoperfusion; preventive measures are therefore directed at securing hydration and correct hemodynamics through fluid perfusion and the use of inotropic or vasoactive drugs, according to the underlying disease condition. Apart from these circumstances, a number of situations could lead to AKI, related to the administration of nephrotoxic drugs, intra-tubular deposits, the administration of iodinated contrast media, liver failure and major surgery (mainly heart surgery). In these cases, in addition to hydration, there are other specific preventive measures adapted to each condition.

Recurrent wheezing and asthma after bocavirus bronchiolitis.

BACKGROUND: Human bocavirus (HBoV) was recently discovered and identified as an important cause of respiratory infection in young children. However, the relationship between HBoV-bronchiolitis and the development of recurrent wheezing has not yet been established. OBJECTIVE: We designed this study in order to describe the mid-term outcome, regarding the development of recurrent wheezing and asthma of HBoV-bronchiolitis patients and to compare it with RSV-bronchiolitis infants. METHODS: We studied 80 children (10 with HBoV and 70 with RSV infection), currently aged ≥4 years and previously hospitalised during the seasons 2004-2009 due to acute bronchiolitis. Epidemiological and clinical data were collected through structured clinical interviews at the follow-up visit. Spirometry and skin prick tests to common food and inhaled allergens were performed. RESULTS: All HBoV-patients developed recurrent wheezing and half of them had asthma at age 5-7 years. Almost 30% required hospital admission for recurrent wheezing. Asthma (odds ratio (OR)=1.28) and current asthma (OR=2.18) were significantly more frequent in children with HBoV-bronchiolitis than in RSV-bronchiolitis. FEV1 values were 99.2±4.8 in HBoV-group vs. 103±11 in RSV-group, p: 0.09. No differences were found with respect to allergic rhinitis, atopic dermatitis, food allergy, proportion of positive prick tests, and family history of atopy or asthma. CONCLUSIONS: Severe HBoV-bronchiolitis in infancy was strongly associated with asthma at 5-7 years.

Blood purification in the critically ill patient. Prescription tailored to the indication (including the pediatric patient).

We maintain a dynamic position on extracorporeal blood purification therapies (EBPT). Continuous therapies are of choice in the hemodynamically unstable patient. We recommend their early introduction in the course of the disease, and starting with a dose of 30-35mL/kg/h. Above all, however, daily re-evaluation is required of the hemodynamic and metabolic situation and water balance of our patients in order to allow dynamic dose adjustment. Some data suggest that continuous EBPT can favorably influence the clinical course of our patients, even in the absence of acute kidney injury. The potential usefulness of hemofiltration at doses higher than the conventional doses (continuous ultrafiltration >50mL/kg/h or pulses of at least 4h a day to more than 100dosesmL/kg/h) for achieving blood purification has also been commented. We review the possible indications of this technique, together with the peculiarities of implementing these therapies in children.

Acute kidney injury: Renal disease in the ICU.

Acute kidney injury (AKI) in the ICU frequently requires costly supportive therapies, has high morbidity, and its long-term prognosis is not as good as it has been presumed so far. Consequently, AKI generates a significant burden for the healthcare system. The problem is that AKI lacks an effective treatment and the best approach relies on early secondary prevention. Therefore, to facilitate early diagnosis, a broader definition of AKI should be established, and a marker with more sensitivity and early-detection capacity than serum creatinine - the most common marker of AKI - should be identified. Fortunately, new classification systems (RIFLE, AKIN or KDIGO) have been developed to solve these problems, and the discovery of new biomarkers for kidney injury will hopefully change the way we approach renal patients. As a first step, the concept of renal failure has changed from being a "static" disease to being a "dynamic process" that requires continuous evaluation of kidney function adapted to the reality of the ICU patient.

Multicenter study of epidemiological cutoff values and detection of resistance in Candida spp. to anidulafungin, caspofungin, and micafungin using the Sensititre YeastOne colorimetric method.

Neither breakpoints (BPs) nor epidemiological cutoff values (ECVs) have been established for Candida spp. with anidulafungin, caspofungin, and micafungin when using the Sensititre YeastOne (SYO) broth dilution colorimetric method. In addition, reference caspofungin MICs have so far proven to be unreliable. Candida species wild-type (WT) MIC distributions (for microorganisms in a species/drug combination with no detectable phenotypic resistance) were established for 6,007 Candida albicans, 186 C. dubliniensis, 3,188 C. glabrata complex, 119 C. guilliermondii, 493 C. krusei, 205 C. lusitaniae, 3,136 C. parapsilosis complex, and 1,016 C. tropicalis isolates. SYO MIC data gathered from 38 laboratories in Australia, Canada, Europe, Mexico, New Zealand, South Africa, and the United States were pooled to statistically define SYO ECVs. ECVs for anidulafungin, caspofungin, and micafungin encompassing ≥97.5% of the statistically modeled population were, respectively, 0.12, 0.25, and 0.06 µg/ml for C. albicans, 0.12, 0.25, and 0.03 µg/ml for C. glabrata complex, 4, 2, and 4 µg/ml for C. parapsilosis complex, 0.5, 0.25, and 0.06 µg/ml for C. tropicalis, 0.25, 1, and 0.25 µg/ml for C. krusei, 0.25, 1, and 0.12 µg/ml for C. lusitaniae, 4, 2, and 2 µg/ml for C. guilliermondii, and 0.25, 0.25, and 0.12 µg/ml for C. dubliniensis. Species-specific SYO ECVs for anidulafungin, caspofungin, and micafungin correctly classified 72 (88.9%), 74 (91.4%), 76 (93.8%), respectively, of 81 Candida isolates with identified fks mutations. SYO ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin, micafungin, and especially caspofungin, since testing the susceptibilities of Candida spp. to caspofungin by reference methodologies is not recommended.

Hospital admission due to respiratory viral infections in moderate preterm, late preterm and term infants during their first year of life.

BACKGROUND: Respiratory viral infections are a major cause of hospitalisation in infants <1 year and might cause severe symptoms in preterm infants. Our aim was to analyse admissions due to respiratory infections in moderate, late and term infants, and to identify risk factors for hospitalisation in preterm versus term. METHODS: Prospective study in a cohort of moderate and late preterm, and term infants born between October/2011 and December/2012. Admissions due to respiratory infections during the first year of life were analysed and compared among moderate (32-33), late (34-36) and term infants. Sixteen respiratory viruses were detected by RT-PCR. Clinical data were collected. RESULTS: 30 (20.9%) out of 143 preterm infants required admission for respiratory infection, versus 129 (6.9%) of 1858 term infants born in the same period (p<0.0001, OR: 3.6 CI 2.0 to 5.0). Hospitalised children had a higher prevalence of hyaline membrane disease (HMD) at birth (p<0.001, OR: 7.7 CI: 2.121 to 27.954) and needed more mechanical ventilation (p<0.001, OR: 5.7 CI: 1.813 to 18.396). Virus was identified in 25/30 (83%) preterm babies, and in 110/129 (85%) term infants. The most frequent viruses in preterm infants were RSV (76%) rhinovirus (20%). Clinical and epidemiological characteristics among term and preterm infants were similar. CONCLUSIONS: The risk of respiratory admissions during the first year of life is up to 3.6 times higher in moderate and late preterm. Once admitted, clinical features of respiratory episodes requiring hospitalisation are similar among term and preterm infants. Hyaline membrane disease and mechanical ventilation were also risk factors for respiratory admissions.

Estimation of the prevalence of latent tuberculosis infection in patients with moderate to severe plaque psoriasis in Spain: The Latent study.

BACKGROUND AND OBJECTIVE: Anti-tumor necrosis factor therapy for moderate to severe psoriasis can increase the risk of active tuberculosis in patients who have latent tuberculosis infection (LTBI). The main objective of this study was to estimate the prevalence of LTBI in patients with moderate to severe plaque psoriasis being treated in dermatology clinics in Spain. MATERIAL AND METHOD: Non-interventional, cross-sectional, national epidemiological study conducted in Spain in 2011-2012. Patients with moderate to severe plaque psoriasis were included if they had undergone at least one tuberculin skin test (TST) and/or been evaluated with an interferon-γ release assay (IGRA) based on enzyme-linked immunosorbent assay (QuantiFERON(®) TB Gold In-Tube) in the 2 years preceding the study. RESULTS: Data for 440 patients were valid for analysis. In total, 97.7% of the patients had undergone a TST, with a positive result in 23%. Of the 238 patients in whom the initial result was negative, 5% converted to positive on re-testing for a booster effect. IGRA results were available for 16.8%, 20.5% of them positive. Two of the patients with positive IGRA results had a negative TST. The prevalence of LTBI in the whole sample was 26.6%. The degree of concordance between the TST and the IGRA was moderate (κ=0.516; P<.001). CONCLUSIONS: The prevalence of LTBI in this study was similar to previous estimates for Spain.

Comparison of the accuracy of CT colonography and colonoscopy in the diagnosis of colorectal cancer.

AIM: The available evidence was reviewed to compare the effectiveness of CT colonography with that of colonoscopy for colorectal cancer (CRC) screening. METHOD: An electronic search was conducted using PubMed, EMBASE, the Cochrane Library and Centre for Reviews and Dissemination databases, from inception to July 2009. Studies were included if investigations used CT colonography for CRC screening in asymptomatic populations. Studies were excluded if investigations were conducted for the diagnosis of CRC or in elderly, high-risk or symptomatic populations. RESULTS: Of the 213 references identified, nine studies were included. The specificity of CT colonography in screening for CRC was high, although it decreased with decreasing diameter of polyp to be detected. The sensitivity of CT colonography for the detection of polyps < 6 mm in diameter was low and heterogeneous, although it was higher for polyps > 10 mm. The main factors contributing to a greater sensitivity of CT colonography were the inclusion of only populations with an average CRC risk and colonic insufflation with CO2 . The incidence of adverse effects was very low for both tests. CONCLUSION: CT colonography has high specificity but heterogeneous sensitivity, although in most cases it is not as sensitive or specific as conventional colonoscopy. CT colonography could therefore be useful as a screening test for populations with an average risk of CRC.

Pseudomonas aeruginosa bloodstream infections in children and adolescents: risk factors associated with carbapenem resistance and mortality.

BACKGROUND: Pseudomonas aeruginosa bloodstream infections (PA-BSIs) are a serious disease and a therapeutic challenge due to increasing resistance to carbapenems. Our objectives were to describe the prevalence and risk factors associated with carbapenem resistance (CR) and mortality in children with PA-BSI. METHODS: A retrospective, multi-centre study was carried out, including patients aged <20 years with PA-BSI in four tertiary hospitals in Madrid (Spain) during 2010-2020. Risk factors for CR PA-BSIs and 30-day mortality were evaluated in a multi-variable logistic regression model. RESULTS: In total, 151 patients with PA-BSI were included, with a median age of 29 months (interquartile range: 3.5-87.1). Forty-five (29.8%) cases were CR, 9.9% multi-drug resistant and 6.6% extensively drug resistant. The prevalence of CR remained stable throughout the study period, with 26.7% (12/45) of CR mediated by VIM-type carbapenemase. Patients with BSIs produced by CR-PA were more likely to receive inappropriate empiric treatment (53.3% vs 5.7%, P<0.001) and to have been previously colonized by CR-PA (8.9% vs 0%, P=0.002) than BSIs caused by carbapenem-susceptible P. aeruginosa. CR was associated with carbapenem treatment in the previous month (adjusted odds ratio (aOR) 11.15) and solid organ transplantation (aOR 7.64). The 30-day mortality was 23.2%, which was associated with mechanical ventilation (aOR 4.24), sepsis (aOR 5.72), inappropriate empiric antibiotic therapy (aOR 5.86), and source control as a protective factor (aOR 0.16). CONCLUSION: This study shows a concerning prevalence of CR in children with PA-BSIs, leading to high mortality. Inappropriate empiric treatment and sepsis were associated with mortality. The high prevalence of CR with an increased risk of inappropriate empiric treatment should be closely monitored.

Expert report on psoriasis: Spanish dermatologists' opinions on the use of biologic agents to manage moderate to severe psoriasis in adults.

BACKGROUND: Although national guidelines on biologic agents for treating moderate to severe psoriasis in adults have been published in several countries, increased knowledge on the practical aspects of their implementation is required. OBJECTIVE: The objective of this study was to survey Spanish dermatologists to determine their expert opinions on practical aspects of psoriasis treatment with biologics. MATERIALS AND METHODS: An online survey was sent to 309 dermatologists who belong to the Spanish Psoriasis Group and/or the Spanish Academy of Dermatology and Venereology (AEDV). The questionnaire was designed specifically for the study and included items on various aspects of the treatment of psoriasis in clinical practice. Six coordinators in different geographic areas worked together to write the final expert report. RESULTS: The response rate was 97% (300 returned questionnaires). The biologics preferred, or considered to be the best option (median score 4 out of 4 points) by respondents, were infliximab for its short-term efficacy (74% of the respondents) and rapid onset of action (78%); ustekinumab for convenience of administration (73%); and etanercept because of its suitability for cyclic treatment (71%), safety in long-term use (72%), and the possibility of temporary interruption of treatment under certain circumstances (76%). Etanercept was assigned the highest evaluations for safety and expected survival time (scored 5 on each item by 49% and 33% of the respondents, respectively). Thirty percent of the respondents considered that clinical guidelines contain important information for therapeutic management of psoriasis. CONCLUSIONS: This study provides a unique perspective on the opinions of a large sample of dermatologists as regards current treatment of psoriasis with biologics in Spain.

Long-term acute infections during a bovine viral diarrhea virus (BVDV) outbreak in dairy farm from Galicia (NW Spain).

An observational study describes an outbreak of bovine viral diarrhea virus (BVDV) in a dairy herd in Spain. The herd was subjected to a voluntary control program. In a sampling carried out in June 2020, bulk tank milk antibody levels increased compared to the previous sampling. Additionally, serum samples from 4 young heifers also tested positive for antibodies. Since the results were consistent with a recent infection, we proceeded to detect possible persistently infected (PI) animals using antigen ELISA (on serum/ear-notch samples), following the program guidelines. From this moment on, 42 animals tested positive for BVDV antigen, of which 17 were under typical acute infection (AI), 13 were deemed as PI, and eight died early on the farm before having information to determine their status. The remaining 4 showed intriguing test results consistent with a long-term AI since they tested BVDV positive in at least two antigen tests more than 3 weeks apart. Thus, one animal was positive until 80 days of age in serum, and others even for longer periods in ear-notch samples, until they finally tested negative for BVDV. Based on these results, longer follow-up may be necessary in BVDV positive animals to accurately confirm persistent infection.

Pharmaceutical active compounds in sewage sludge: Degradation improvement and conversion into an organic amendment by bioaugmentation-composting processes.

Around 143,000 chemicals find their fate in wastewater treatment plants in the European Union. Low efficiency on their removal at lab-based studies and even poorer performance at large scale experiments have been reported. Here, a coupled biological technology (bioaugmentation and composting) is proposed and proved for pharmaceutical active compounds degradation and toxicity reduction. The optimization was conducted through in situ inoculation of Penicillium oxalicum XD 3.1 and an enriched consortium (obtained from non-digested sewage sludge), into pilot scale piles of sewage sludge under real conditions. This bioaugmentation-composting system allowed a better performance of micropollutants degradation (21 % from the total pharmaceuticals detected at the beginning of the experiment) than a traditional composting process. Particularly, inoculation with P. oxalicum allowed the degradation of some recalcitrant compounds like carbamazepine, cotinine and methadone, and also produced better stabilization features in the mature compost (significant passivation of copper and zinc, higher macronutrients value, adequate physicochemical conditions for soil direct application and less toxic effect on germination) compared to the control and the enriched culture. These findings provide a feasible, alternative strategy to obtain a safer mature compost and a better removal of micropollutants performance at large scale.

Modifications of long-term heart rate variability produced in an experimental model of diet-induced metabolic syndrome.

Metabolic syndrome (MetS) has been linked to a higher prevalence of cardiac arrhythmias, the most frequent being atrial fibrillation, but the mechanisms are not well understood. One possible underlying mechanism may be an abnormal modulation of autonomic nervous system activity, which can be quantified by analysing heart rate variability (HRV). Our aim was to investigate the modifications of long-term HRV in an experimental model of diet-induced MetS to identify the early changes in HRV and the link between autonomic dysregulation and MetS components. NZW rabbits were randomly assigned to control (n = 10) or MetS (n = 10) groups, fed 28 weeks with high-fat, high-sucrose diet. 24-hour recordings were used to analyse HRV at week 28 using time-domain, frequency-domain and nonlinear analyses. Time-domain analysis showed a decrease in RR interval and triangular index (Ti). In the frequency domain, we found a decrease in the low frequency band. Nonlinear analyses showed a decrease in DFA-α1 and DFA-α2 (detrended fluctuations analysis) and maximum multiscale entropy. The strongest association between HRV parameters and markers of MetS was found between Ti and mean arterial pressure, and Ti and left atrial diameter, which could point towards the initial changes induced by the autonomic imbalance in MetS.