COVID-19 outbreaks surveillance through text mining applied to electronic health records.

BACKGROUND: The COVID-19 pandemic has caused significant disruptions to everyday life and has had social, political, and financial consequences that will persist for years. Several initiatives with intensive use of technology were quickly developed in this scenario. However, technologies that enhance epidemiological surveillance in contexts with low testing capacity and healthcare resources are scarce. Therefore, this study aims to address this gap by developing a data science model that uses routinely generated healthcare encounter records to detect possible new outbreaks early in real-time. METHODS: We defined an epidemiological indicator that is a proxy for suspected cases of COVID-19 using the health records of Emergency Care Unit (ECU) patients and text mining techniques. The open-field dataset comprises 2,760,862 medical records from nine ECUs, where each record has information about the patient's age, reported symptoms, and the time and date of admission. We also used a dataset where 1,026,804 cases of COVID-19 were officially confirmed. The records range from January 2020 to May 2022. Sample cross-correlation between two finite stochastic time series was used to evaluate the models. RESULTS: For patients with age 18 years, we find time-lag () = 72 days and cross-correlation () ~ 0.82, = 25 days and ~ 0.93, and = 17 days and ~ 0.88 for the first, second, and third waves, respectively. CONCLUSIONS: In conclusion, the developed model can aid in the early detection of signs of possible new COVID-19 outbreaks, weeks before traditional surveillance systems, thereby anticipating in initiating preventive and control actions in public health with a higher likelihood of success.

Accuracy of the pacemaker event recorder versus Holter-ECG to detect both symptomatic and asymptomatic ventricular arrhythmias.

BACKGROUND: Although new pacemakers can register cardiac rhythm, few studies were performed evaluating their accuracy in diagnosing ventricular arrhythmias (VA). This study aimed to assess the correlation and agreement between the pacemaker's monitor and the ambulatory Holter in detecting VA. METHODS AND RESULTS: We studied 129 patients with pacemakers, mean age 68.6 ± 19.1 years, 54.8% female. Once Holter monitoring was connected, the pacemakers' event counters were reset and clocks of both systems were synchronized to register electrocardiograms (ECG) simultaneously. Pacemakers were programmed to detect the lowest ventricular rate and lowest number of sequential beats allowed in their event monitors. After 72 hours, Holter and pacemakers records were analyzed. VA was defined in Holter and event monitor, respectively, as: isolated premature ventricular complexes: "PVC"; pairs: "couplets"; nonsustained ventricular tachycardia (NSVT): "triplets"-3 beats; "runs"-4-8 or > 8 beats, and high ventricular rates ("HVR")-3-4 beats. Spearman correlations evaluated whether pacemaker and Holter identified the same parameters. Intraclass correlation coefficients (ICCs) and respective 95% confidence intervals were calculated to assess the concordance between methods. The agreement between both systems was low, except for "triplet" and three beats NSVT (ICC = 0.984). The correlation for more than 10 PVC/h was moderate (Kappa = 0.483). When the pacemaker was programmed to detect HVR sequences of three beats lower than 140 bpm (< 140/3), the correlation with NSVT was perfect (r = 1) and agreement was also quite high (ICC = 0.800). CONCLUSIONS: Pacemakers' event monitors underestimate the occurrence of ventricular arrhythmias detected by Holter. Standardization of pacemakers' algorithms is required before using this function for patients' clinical follow-up.

[Analysis of anatomical pieces preservation with polyester resin for human anatomy study]. / Análise de peças anatômicas preservadas com resina de poliester para estudo em anatomia humana.

OBJECTIVE: To evaluate the use of polyester resin in preserving anatomical specimens for the study of human anatomy. METHODS: We used 150 anatomical specimens, comprised of unfixed (fresh), fixed in 10% formalin and vascular casts of organs injected with vinyl acetate and polyester resin. The solution used consisted of polyester resin with the diluent styrene monomer and catalyst (peroxol). After embedding in this solution, models in transparent resin were obtained, allowing full observation of structures and conservation of the specimens used. RESULTS: upon evaluation of the specimens, we observed a high degree of transparency, which promoted a complete visualization of structures with perfect preservation of the anatomy. The average time for the completion of the embedding was 48 hours. Only 14 specimens (9.3%) were lost during the preparation. CONCLUSION: Polyester resin can be used for preserving anatomical specimens for teaching human anatomy in a practical, aesthetic and durable way.

Fibrosis, myocardial crossings, disconnections, abrupt turns, and epicardial reflections: do they play an actual role in human permanent atrial fibrillation? A controlled necropsy study.

Atrial myocardium fibrosis and other alterations of fiber continuity and potential circuit reentrancy (disconnections, abrupt turns, crossings, and epicardial reflections) are thought to play an important role in permanent atrial fibrillation. However, few studies have been performed in human beings. Some of them are only descriptive, and controls were usually normal hearts; thus, differences between cases and controls could be related to the underlying disease rather than the arrhythmia. We quantified by histomorphometry the above characteristics in nine samples (three from the left atrium, three from around fat pads, one from the right atrium, one from the cavum-tricuspid isthmus, and one from the ventricular septum) from 13 necropsy hearts of patients with permanent atrial fibrillation and compared the findings with those from 13 control cases with the same diseases but without any atrial arrhythmia. Statistical analysis was performed using generalized estimating equations and a normal linear mixed model for repeated measures, with significance defined as P ≤.05. No differences were found in fibrosis (estimated as collagen/(collagen+myocardium) ratio-0.26 vs. 0.23, P=.35), the presence of disconnections (70.1 vs. 61.5, P=.09), abrupt turns (43.6 vs. 45.3, P=.84), or epicardial reflections (9.4 vs. 14.5, P=.12). The only difference identified was that cases with permanent atrial fibrillation exhibited fewer crossings than those without (79.5 vs. 91.5, P=.02). In conclusion, alterations in myocardial fiber continuity, including fibrosis, seem to reflect a generalized myocardial disorganization of the atria in cardiac disease but are not specifically related to permanent atrial fibrillation.

Anatomic relations of the Marshall vein: importance for catheterization of the coronary sinus in ablation procedures.

AIMS: Our objective was to study the anatomic relations of the human left atrial oblique vein (Marshall vein), particularly of its ostium opening into the coronary sinus, in order to guide ablation procedures related to that vein. METHODS AND RESULTS: The study was carried out in 23 heart-specimens (mean weight 446 +/- 204 g) of individuals whose mean ages were 43 +/- 21 years, 20 males. The coronary sinus was opened longitudinally, exposing the ostium of the tributary veins; the Vieussens valve was looked for, as well as its relationship to the left atrial oblique vein. The diameters of the left atrial oblique vein and the coronary sinus ostia were measured and the distance between them was determined. The left atrial oblique vein could be identified in 20 (87%) of the hearts, while the Vieussens valve was present in 17 (74%) of the specimens (in 16 of which the left atrial oblique vein was identified). In such condition, the vein was adjacent to the Vieussens valve and proximally positioned relative to the coronary sinus ostium in most of them (14/16 cases). The mean diameters of the left atrial oblique vein and of the coronary sinus ostia were, respectively, 1.23 +/- 0.38 and 8.22 +/- 1.88 mm. The mean distance between both ostia was 30.9 +/- 10.2 mm. CONCLUSION: When present, the left atrial oblique vein can be easily recognized, adjacent to the Vieussens valve. The mean distance between the coronary sinus opening and left atrial oblique vein ostium was around 30 mm, independently of the heart weight and the presence of cardiomegaly.