Chest radiography or computed tomography for COVID-19 pneumonia? Comparative study in a simulated triage setting.

INTRODUCTION: For the management of patients referred to respiratory triage during the early stages of the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, either chest radiography or computed tomography (CT) were used as first-line diagnostic tools. The aim of this study was to compare the impact on the triage, diagnosis and prognosis of patients with suspected COVID-19 when clinical decisions are derived from reconstructed chest radiography or from CT. METHODS: We reconstructed chest radiographs from high-resolution CT (HRCT) scans. Five clinical observers independently reviewed clinical charts of 300 subjects with suspected COVID-19 pneumonia, integrated with either a reconstructed chest radiography or HRCT report in two consecutive blinded and randomised sessions: clinical decisions were recorded for each session. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and prognostic value were compared between reconstructed chest radiography and HRCT. The best radiological integration was also examined to develop an optimised respiratory triage algorithm. RESULTS: Interobserver agreement was fair (Kendall's W=0.365, p<0.001) by the reconstructed chest radiography-based protocol and good (Kendall's W=0.654, p<0.001) by the CT-based protocol. NPV assisted by reconstructed chest radiography (31.4%) was lower than that of HRCT (77.9%). In case of indeterminate or typical radiological appearance for COVID-19 pneumonia, extent of disease on reconstructed chest radiography or HRCT were the only two imaging variables that were similarly linked to mortality by adjusted multivariable models CONCLUSIONS: The present findings suggest that clinical triage is safely assisted by chest radiography. An integrated algorithm using first-line chest radiography and contingent use of HRCT can help optimise management and prognostication of COVID-19.

1:1 atrial flutter induced by flecainide, whilst the patient was at rest.

Class Ic antiarrhythmic agents flecainide and propafenone are amongst the drugs most frequently prescribed to control atrial arrhythmias, in particular atrial fibrillation (AF). Despite being cited in some guidelines as a warning when using 1c antiarrhythmic agents, atrial flutter (AFl) with 1:1 atrioventricular conduction is rare in adults, with only small series reported in the literature, mainly including patients having 1:1 AFl during physical activity, and often associated with a predisposing factor, namely a dual AV nodal conduction pathway. We describe here a rare case of 1:1 AFl induced by flecainide, developing whilst the patients was resting in bed, in a 56 year old man who presented to the local Emergency Department (ED) complaining for palpitations due to acute-onset AF. After ED discharge, the patient was then evaluated in the Arrhythmologic Clinic of the Cardiology Department, and channellopaties were excluded. This case report should raise alertness in emergency physicians about this serious and potentially fatal side effect of flecainide, when using this drug for pharmacological cardioversion of AF.

Incidence of primary spontaneous pneumothorax is not associated with microclimatic variations. Results of a seven-year survey in a temperate climate area.

Some diseases, such as renal colic and atrial fibrillation, display an association with microclimatic variations. In particular, despite a correlation has been reported between incidence of primary spontaneous pneumothorax (PSP) and meteorological variations, the evidence remains poor and conflictual. The aim of this study was to assess the influence of day-by-day meteorological variations on the number of visits for PSP in the Emergency Department (ED). All PSP cases were retrieved from the hospital database from January 2008 to December 2014. For all the observational days, meteorological data about the Parma Province were obtained from the Environment and Climate Regional Agency.  The correlation between ED visits for PSP and variation of air temperature (T°), atmospheric pressure (hPa) and humidity (%) was then tested. The chronological data of all the visits for PSP were correlated with climate data by univariate linear regressions analysis. A total number of 608.215 ED visits were recorded during the observational period, with an average of 238 patients per day. Overall, 257 PSP cases were observed (mean age 37±21 years), 79% males and 21% females. No significant correlation between average daily visits for SP and daily change of average temperature, humidity, or atmospheric pressure was observed throughout the observational period (p>0.05 for all). The results of the study show that the incidence of PSP is not significantly associated with changes of microclimatic variables.

[Sometimes they come back! A case of Shoshin Beriberi in Northern Italy (2012)]. / A volte ritornano! Un caso di Shoshin Beriberi nel Nord Italia (2012).

A 78-year-old man presented to the emergency department with symptoms and signs suggestive of heart failure. Only after a long interview we discovered that the patient has been eating, for over 20 years, only chestnut honey and chestnut jam produced by himself. He refused any other foods, because of the fear of being poisoned; he did not drink alcohol at all. The clinical picture was attributable to Beriberi, and the patient recovered promptly after treatment with thiamine. A high clinical suspicion and an early thiamine supplementation might shorten the duration of work-up and hospital length of stay, as well as prevent extensive and expensive diagnostic work-up, thus simplifying the clinical management.

Rhabdomyolysis: historical background, clinical, diagnostic and therapeutic features.

Rhabdomyolysis, a term used to describe the rapid breakdown of striated muscle, is characterized by rupture and necrosis of muscle fibers. This process results in the release of cell breakdown products into the bloodstream and extracellular space. Although direct muscle injury remains the most common cause of muscle injury, additional causes include hereditary enzyme disorders, drugs, toxins, endocrinopathies, malignant hyperthermia, neuroleptic malignant syndrome, heatstroke, hypothermia, electrolyte alterations, diabetic ketoacidosis and non-ketotic hyperosmolar coma, severe hypo- or hyperthyroidism and bacterial or viral infections. The classic triad of symptoms includes muscle pain, weakness and dark urine, although more than 50% of the patients do not complain of muscle pain or weakness. Additional systemic symptoms include fever, general malaise, tachycardia, nausea and vomiting. The laboratory diagnosis is based essentially on the measurement of creatine kinase in serum or plasma. Plasma and urine myoglobin measurement might be useful in the early stages of the syndrome and for identifying a subset of patients with minor skeletal muscle injury. Patient monitoring is pivotal (the mortality rate is as high as 8%), and should be focused on preventing the detrimental consequences, that often include renal disease and coagulopathy. In the pre-hospital setting, forced hydration with 1.5-2 L of sterile saline solution should be started immediately, followed by 1.5-2 L/h. Following hospital admission, continuous hydration should be ensured, alternating the saline solution with a 5% glucose solution. In the presence of myoglobinuria, urine should be alkalinized by use of sodium bicarbonate solution. Clin Chem Lab Med 2010;48:749-56.

Impact of the COVID-19 epidemic on census, organization and activity of a large urban Emergency Department.

BACKGROUND: The spread of coronavirus disease 2019 (COVID-19) is overwhelming the response of many regional health services across Italy. This article aims to report and discuss the data of the first 8 weeks of COVID-19 epidemic in the emergency department (ED) of the University Hospital of Parma. METHODS: The ED visits were analyzed as follows: total ED visits, divided in COVID-19/ non-COVID-19 cases, and in trauma-related/non-trauma-related cases; outcome (i.e., discharged, admitted, dead in the ED) of patients, altogether or stratified according to triage class; age classes of the entire ED population. RESULTS: Total ED visits decreased starting from the first days of the outbreak, then exhibiting progressive growth afterwards. COVID suspected cases rapidly increased, whereas non-COVID suspected dropped and remained well below the standard. Trauma-related cases declined, both as ED visits and as hospital admissions. The percentage and absolute number of patients admitted to hospital wards progressively increased, rapidly overwhelming the number of cases that could be discharged. The admission rate in the lowest priority classes also displayed a marked increase. The youngest age classes dramatically declined, whilst the oldest progressively increased, remaining considerably over the standard rate of the local ED. CONCLUSIONS: The COVID-19 pandemic has obliged the health care systems to undergo a paradigm shift. Even triage criteria have partially lost their meaning, as shown by the dramatic increase of hospital admissions, even in the lowest priority classes. A deep re-organizational process of the ED was undertaken. Hospitals must be constantly resilient and prepared to these new emergencies in terms of equipment, medical and nurses staff, larger bed capacity in short time, availability of intensive and sub-intensive beds, and flexibility.

Barbel cholera, a rare but still possible food-borne poisoning. Case report and narrative review.

The gastro enteric toxic effects of the barbel eggs have been described up to two centuries ago, but deliberate or serendipitous ingestion of this fish product still occur, often eliciting a gastrointestinal syndrome usually known as barbel cholera. Barbel cholera is a self-limited gastrointestinal diarrheic syndrome that develops 2 to 4 hours after ingestion of the eggs, lasting up to 12-36 hours, nearly always complicated by vomiting and severe abdominal pain. The disease is usually self-limited, and the prognosis is thus benign even without hospitalization and medical treatment. Rarely, however, barbel cholera may be complicated by massive diarrhea, and the patients can develop bradycardia, oligo-anuria, and eventually hypovolemic shock. In this article we describe a rare case of barbel cholera, highlighting both the diagnostic difficulties in identifying it, and the importance of obtain an accurate history, focused on recently ingested food, thus addressing the clinical management on supportive treatment, expecting symptoms' improvement usually within 36 hours.

Improved efficiency and cost reduction in the emergency department by replacing contemporary sensitive with high-sensitivity cardiac troponin immunoassay.

BACKGROUND: Although unquestionable evidence has been provided that high-sensitive (HS) cardiac troponin (cTn) immunoassay outperform the former contemporary-sensitive techniques, some clinicians are still hesitant to implement HS methods in routine clinical practice. This study was hence planned to evaluate the impact of replacing a contemporary-sensitive with HS cTnI immunoassay on hospital and laboratory workload. METHODS: Information on the total number of cTnI tests ordered, total number of blood samples collected, total number of CK-MB tests ordered, number of patients with the first HS-cTnI value below the limit of detection (LoD) and cumulative HS-cTnI values was extracted from the local hospital information system for the semesters before and after the HS method was introduced. RESULTS: Although the total emergency department (ED) visits modestly increased after introducing HS-cTnI, the number of total cTnI tests declined by over 10%. A substantial reduction of single-sample test requests was noted, accompanied by a considerable decline of 3- and 4-sample collections (i.e., -61% and -73%, respectively). A high percentage of patients (27.5%) displayed HS-cTnI values

Visits for alcohol-related problems in a large urban Emergency Department. Results of a 15-year survey.

Alcohol abuse is associated with a high burden of morbidity and mortality. Nevertheless, definitive epidemiological data on alcohol-related visits in the emergency department (ED) is substantially lacking. This study was aimed to analyze the epidemiological patterns and temporal trends of alcohol-related visits in the local ED, and assessing the healthcare burden of cases needing hospital admission. All patients visited for alcohol-related problems between the years 2002-2016 were anonymously identified from the hospital database. All cases were classified according to the main cause leading to ED, age and gender, time of presentation, disposition. Overall, 8014 cases were identified (2249 women and 5765 men). Women were younger than men. The overall trend during the study period was characterized by a constant increase in the number of alcohol-related ED admissions. A significant number of subjects had multiple alcohol-related visits. A total number of 747 patients were visited twice, 259 three times and 107 four times. A mostly nocturnal pattern of ED presentation was observed in both genders, peaking between midnight and 2 AM, and an increased number of visits was recorded during the weekends. The vast majority of patients (64%) could be discharged within 6 hours, but a considerable number needed longer observation and treatment in the ED. Overall, 7551 patients were discharged from the ED, whilst 462 patients needed hospital admission, 179 for traumatic injuries and 283 for non-traumatic causes. The decreasing age of subjects admitted to the ED with alcohol-related problems should now be regarded as a public healthcare issue.

Is Google Trends a reliable tool for digital epidemiology? Insights from different clinical settings.

Internet-derived information has been recently recognized as a valuable tool for epidemiological investigation. Google Trends, a Google Inc. portal, generates data on geographical and temporal patterns according to specified keywords. The aim of this study was to compare the reliability of Google Trends in different clinical settings, for both common diseases with lower media coverage, and for less common diseases attracting major media coverage. We carried out a search in Google Trends using the keywords "renal colic", "epistaxis", and "mushroom poisoning", selected on the basis of available and reliable epidemiological data. Besides this search, we carried out a second search for three clinical conditions (i.e., "meningitis", "Legionella Pneumophila pneumonia", and "Ebola fever"), which recently received major focus by the Italian media. In our analysis, no correlation was found between data captured from Google Trends and epidemiology of renal colics, epistaxis and mushroom poisoning. Only when searching for the term "mushroom" alone the Google Trends search generated a seasonal pattern which almost overlaps with the epidemiological profile, but this was probably mostly due to searches for harvesting and cooking rather than to for poisoning. The Google Trends data also failed to reflect the geographical and temporary patterns of disease for meningitis, Legionella Pneumophila pneumonia and Ebola fever. The results of our study confirm that Google Trends has modest reliability for defining the epidemiology of relatively common diseases with minor media coverage, or relatively rare diseases with higher audience. Overall, Google Trends seems to be more influenced by the media clamor than by true epidemiological burden.

Clinical presentation and epidemiology of brain tumors firstly diagnosed in adults in the Emergency Department: a 10-year, single center retrospective study.

BACKGROUND: Several patients with new onset brain tumors present to the Emergency Department (ED) complaining for new symptoms. Although information exists on symptom prevalence in the entire population of patients with brain tumors, little is known about the clinical presentation in ED. This retrospective study was planned to investigate clinical presentation and epidemiology of brain tumors firstly diagnosed in a large urban ED throughout a 10-year period. METHODS: All medical records of patients aged ≥18 years, discharged from our ED with a diagnosis of brain tumor were retrieved from the electronic hospital database during a 10-year period (2006 to 2015). The records were reassessed for selecting only brain tumors firstly diagnosed in the ED. The symptoms at presentation were divided in six categories: (I) headache; (II) seizures; (III) focal signs; (IV) altered mental status; (V) nausea/vomiting/dizziness; (VI) trauma. For all cases, the hospital record was retrieved, to obtain histologic classification of tumors. Patients with inflammatory neoformations were excluded from the study. RESULTS: Overall, 205 patients with firstly diagnosed brain tumor were identified among 870,135 ED visits (i.e., <1%). Glial tumors were the most frequent (50% of the entire sample). No significant differences were found between mean age of patients in the different histologically based groups (meningiomas 66±14; glioblastomas 65±16 years; metastases 66±13 years; other miscellaneous 66±19 years). Focal signs accounted for more than 50% of all presentation signs/symptoms. CONCLUSIONS: First presentation of brain tumor in the ED is not a rare occurrence, so that the emergency physicians should be aware of this possibility.

Non-traumatic rhabdomyolysis: Background, laboratory features, and acute clinical management.

Rhabdomyolysis is a relatively rare condition, but its clinical consequences are frequently dramatic in terms of both morbidity and mortality. Although no consensus has been reached so far about the precise definition of this condition, the term rhabdomyolysis describes a rapid breakdown of striated, or skeletal, muscle. It is hence characterized by the rupture and necrosis of muscle fibers, resulting in release of cell degradation products and intracellular elements within the bloodstream and extracellular space. Notably, the percentage of patients with rhabdomyolysis who develop acute kidney injury, the most dramatic consequence, varies from 13% to over 50% according to both the cause and the clinical and organizational setting where they are diagnosed. Despite direct muscle injury (i.e., traumatic rhabdomyolysis) remains the most common cause, additional causes, frequently overlapping, include hypoxic, physical, chemical or biological factors. The conventional triad of symptoms includes muscle pain, weakness and dark urine. The laboratory diagnosis is essentially based on the measurement of biomarkers of muscle injury, being creatine kinase (CK) the biochemical "gold standard" for diagnosis, and myoglobin the "gold standard" for prognostication, especially in patients with non-traumatic rhabdomyolysis. The essential clinical management in the emergency department is based on a targeted intervention to manage the underlying cause, combined with infusion of fluids and eventually sodium bicarbonate. We will present and discuss in this article the pathophysiological and clinical features of non-traumatic rhabdomyolysis, focusing specifically on Emergency Department (ED) management.

Epidemiology and outcomes of acute abdominal pain in a large urban Emergency Department: retrospective analysis of 5,340 cases.

BACKGROUND: Acute abdominal pain (AAP) accounts for 7-10% of all Emergency Department (ED) visits. Nevertheless, the epidemiology of AAP in the ED is scarcely known. The aim of this study was to investigate the epidemiology and the outcomes of AAP in an adult population admitted to an urban ED. METHODS: We made a retrospective analysis of all records of ED visits for AAP during the year 2014. All the patients with repeated ED admissions for AAP within 5 and 30 days were scrutinized. Five thousand three hundred and forty cases of AAP were analyzed. RESULTS: The mean age was 49 years. The most frequent causes were nonspecific abdominal pain (NSAP) (31.46%), and renal colic (31.18%). Biliary colic/cholecystitis, and diverticulitis were more prevalent in patients aged >65 years (13.17% vs. 5.95%, and 7.28% vs. 2.47%, respectively). Appendicitis (i.e., 4.54% vs. 1.47%) and renal colic (34.48% vs. 20.84%) were more frequent in patients aged <65 years. NSAP was the most common cause in both age classes. Renal colic was the most frequent cause of ED admission in men, whereas NSAP was more prevalent in women. Urinary tract infection was higher in women. Overall, 885 patients (16.57%) were hospitalized. Four hundred and eighty-five patients had repeated ED visits throughout the study period. Among these, 302 patients (6.46%) were readmitted within 30 days, whereas 187 patients (3.82%) were readmitted within 5 days. Renal colic was the first cause for ED readmission, followed by NSAP. In 13 cases readmitted to the ED within 5 days, and in 16 cases readmitted between 5-30 days the diagnosis was changed. CONCLUSIONS: Our study showed that AAP represented 5.76% of total ED visits. Two conditions (i.e., NSAP and renal colic) represented >60% of all causes. A large use of active clinical observations during ED stay (52% of our patients) lead to a negligible percentage of changing diagnosis at the second visit.

Influence of air temperature variations on incidence of epistaxis.

OBJECTIVE: Epistaxis is the most common ear, nose, and throat emergency observed in the emergency department (ED). An increased frequency of this condition has been observed during cooler months, but the results of available studies are controversial. The aim of this study was to investigate the seasonality and association of epistaxis presentations to a large urban ED with variations of air temperature and humidity. METHODS: This study was a retrospective case series. Information on all the patients who presented for epistaxis in the ED of the Academic Hospital of Parma during the years 2003-2012 and ages ≥ 14 years were retrieved from the hospital data base, excluding those attributable to trauma. The chronologic data of all visits were associated with climate data (air temperature and humidity) by univariate linear regression analysis. RESULTS: Among the 819,596 ED patients seen throughout the observational period, 5404 were admitted for epistaxis. Of these, 5220 were discharged from the ED, whereas 184 (3.4%) needed hospital admission. A strong seasonality of epistaxis was observed, with a peak during winter. A strong negative correlation was also found between the daily number of epistaxes and the mean daily temperature in the whole population as well as in patient subgroups (those undergoing anticoagulant or antiplatelet therapy, or those with hypertension, inherited bleeding disorders, liver cirrhosis, or advanced malignancy). A weaker correlation was also found between air humidity and epistaxis but only in certain subgroups. CONCLUSIONS: The results of this study provided a contribution to improve our understanding of the epidemiology of epistaxis and for specific health policies that should also be planned by considering the seasonality of nosebleed.

Serum bilirubin value predicts hospital admission in carbon monoxide-poisoned patients. Active player or simple bystander?

OBJECTIVES: Although carbon monoxide poisoning is a major medical emergency, the armamentarium of recognized prognostic biomarkers displays unsatisfactory diagnostic performance for predicting cumulative endpoints. METHODS: We performed a retrospective and observational study to identify all patients admitted for carbon monoxide poisoning during a 2-year period. Complete demographical and clinical information, along with the laboratory data regarding arterial carboxyhemoglobin, hemoglobin, blood lactate and total serum bilirubin, was retrieved. RESULTS: The study population consisted of 38 poisoned patients (23 females and 15 males; mean age 39 ± 21 years). Compared with discharged subjects, hospitalized patients displayed significantly higher values for blood lactate and total serum bilirubin, whereas arterial carboxyhemoglobin and hemoglobin did not differ. In a univariate analysis, hospitalization was significantly associated with blood lactate and total serum bilirubin, but not with age, sex, hemoglobin or carboxyhemoglobin. The diagnostic performance obtained after combining the blood lactate and total serum bilirubin results (area under the curve, 0.90; 95% CI, 0.81-0.99; p<0.001) was better than that obtained for either parameter alone. CONCLUSION: Although it remains unclear whether total serum bilirubin acts as an active player or a bystander, we conclude that the systematic assessment of bilirubin may, alongside lactate levels, provide useful information for clinical decision making regarding carbon monoxide poisoning.

A four-year survey on unexpected pregnancy diagnoses in a large urban emergency department in Parma, Italy.

OBJECTIVE: To investigate the rate of unexpected pregnancy diagnoses in the emergency department of the Academic Hospital of Parma, Parma, Italy. METHODS: Data for all patients with a positive ß-human chorionic gonadotropin test between October 2008 and September 2012 were retrieved from the hospital records. Information on age, gender, country of birth, and reason for presenting to the emergency department was collected. RESULTS: During the study period, 160151 visits of female patients were recorded, including 385 (0.2%) women who received a diagnosis of pregnancy; 97 (25.2%) were native Italians and 288 (74.8%) were foreign-born. The percentage of women presenting for trauma did not differ between the two groups, whereas the rate of admission to the obstetrics and gynecology department was higher among natives (20.6% vs 9.0%; P=0.002). Africans represented 66.0% (n=190) of the women with an unexpected pregnancy diagnosis. Nigerians accounted for 20.8% (n=60) of all foreign-born women with a pregnancy diagnosis, although they represented less than 2% of the entire immigrant population. CONCLUSION: Unexpected pregnancy is a problem in the province of Parma, most notably among women from Sub-Saharan Africa. Efforts should be strengthened to provide more fragile groups with easily available family planning information.

Initial blood lactate correlates with carboxyhemoglobin and clinical severity in carbon monoxide poisoned patients.

OBJECTIVE: The aim of this study was to assess the role of blood lactate levels at admission in carbon monoxide (CO)-poisoned patients for establishing severity of poisoning and short term prognosis. METHOD: All cases of CO poisoning visited in the emergency department during the years 2012 and 2013 were retrieved from the hospital database. The concentration of COHb and lactate was assessed in arterial blood in all patients with suspected CO poisoning, along with the plasma concentration of troponin I (TnI). The control population for TnI results consisted in 125 blood donors. RESULTS: Twenty three (61%) out of 38 CO-poisoned patients underwent hyperbaric oxygen (HBO) treatment, and 10 (26%) were admitted to a hospital ward. A significant correlation was found between lactate and COHb (r=0.54; p<0.001), and between lactate and TnI (r=0.44; p=0.001). A significant correlation was also found between COHb and TnI (r=0.38; p=0.020). Blood lactate levels were higher in patients treated with HBO and hospital admission. In multivariate analysis, none of the parameters was associated with HBO treatment, whereas increased value of blood lactate (p=0.036) was the only significant predictor of hospital admission. Twenty five (66%) patients had detectable TnI levels compared to 13% controls (p<0.001), whereas 16% CO-poisoned patients had TnI levels >99th percentile compared to 2% controls (p=0.003). The odds ratio for detectable TnI and TnI >99th percentile in CO-poisoned patients were 13.1 (p<0.001) and 7.6 (p=0.006), respectively. CONCLUSION: Initial blood lactate level may be useful for risk stratification of CO-poisoned patients, especially for predicting hospitalization.

Accidental mushroom poisoning mimicking stroke. A case report and literature review.

We describe here a paradigmatic case of mushroom poisoning mimicking a stroke. A 64-year old male was referred to the emergency department (ED) for a car accident. He was found diaphoretic, hypotensive, bradycardic, and slightly confused at presentation. No signs of trauma were observed on physical examination. The patient had weakness of the right limbs and bilateral severe myosis. The lab tests were normal, except for leukocytosis, mild hyperglycemia, mild hyperazotemia and moderate hypokalemia. The clinical picture, with the exception of miosis, was thereby suggestive for a stroke, which was also considered the cause of the car accident. The patients' wife, who was brought later to the ED, reported that the husband had suffered a stroke 4 years earlier, with residual right hemiparesis. She also referred that the patient showed signs of diaphoresis and confusion, and the car was intentionally driven into the ditch. Among other details, she referred that the husband ate mushrooms that she had personally collected 2 hours before taking the drive. Two mg of atropine, intravenous rehydration and potassium were hence administered in the suspicion of a cholinergic toxydrome, and complete clinical remission was rapidly obtained. Among the mixture of mushrooms eaten by the patient, a mycologist identified Armillaria Mellea (an edible mushroom) and notably Inocybe Fastigiata, a toxic muscarine-containing mushroom, easily confounded with Armillaria. After observation and oral rehydration, the patient was discharged.

Incidence of acute-onset atrial fibrillation correlates with air temperature. Results of a nine-year survey.

Some diseases, such as renal colic, stroke, and myocardial infarction, correlate with seasonality and microclimatic variations. Although evidence is limited and controversial, a correlation between acute-onset atrial fibrillation (AAF) and seasonality has been previously reported. In order to elucidate the possible correlations between weather and incidence of AAF in a country with a temperate climate, the influence of day-by-day climate changes was analyzed based on the number of visits for AAF (defined as onset of symptoms within 48h) in a large urban Emergency Department (ED) of northern Italy. All the episodes of AAF were retrieved from the hospital's electronic database during a period of 3287days (January 2002 to December 2010). Only the cases whose onset occurred within 48h from the ED visit were selected. The total number of ED visits was 725,812 throughout the observational period. Among these, 3633 AAF cases were observed, 52% of which were males. A slight but significant negative linear correlation was found between the number of AAFs and the daily temperature (R=-0.60; p=0.001). No correlation was found between the number of AAFs and the daily humidity (R=-0.07; p=0.2).