Intelligent Electrocardiogram Analysis in Medicine: Data, Methods, and Applications / 中国医学科学杂志(英文版)

Electrocardiogram (ECG) is a low-cost, simple, fast, and non-invasive test. It can reflect the heart's electrical activity and provide valuable diagnostic clues about the health of the entire body. Therefore, ECG has been widely used in various biomedical applications such as arrhythmia detection, disease-specific detection, mortality prediction, and biometric recognition. In recent years, ECG-related studies have been carried out using a variety of publicly available datasets, with many differences in the datasets used, data preprocessing methods, targeted challenges, and modeling and analysis techniques. Here we systematically summarize and analyze the ECG-based automatic analysis methods and applications. Specifically, we first reviewed 22 commonly used ECG public datasets and provided an overview of data preprocessing processes. Then we described some of the most widely used applications of ECG signals and analyzed the advanced methods involved in these applications. Finally, we elucidated some of the challenges in ECG analysis and provided suggestions for further research.

Electrocardiogram data recognition algorithm based on variable scale fusion network model / 生物医学工程学杂志

The judgment of the type of arrhythmia is the key to the prevention and diagnosis of early cardiovascular disease. Therefore, electrocardiogram (ECG) analysis has been widely used as an important basis for doctors to diagnose. However, due to the large differences in ECG signal morphology among different patients and the unbalanced distribution of categories, the existing automatic detection algorithms for arrhythmias have certain difficulties in the identification process. This paper designs a variable scale fusion network model for automatic recognition of heart rhythm types. In this study, a variable-scale fusion network model was proposed for automatic identification of heart rhythm types. The improved ECG generation network (EGAN) module was used to solve the imbalance of ECG data, and the ECG signal was reproduced in two dimensions in the form of gray recurrence plot (GRP) and spectrogram. Combined with the branching structure of the model, the automatic classification of variable-length heart beats was realized. The results of the study were verified by the Massachusetts institute of technology and Beth Israel hospital (MIT-BIH) arrhythmia database, which distinguished eight heart rhythm types. The average accuracy rate reached 99.36%, and the sensitivity and specificity were 96.11% and 99.84%, respectively. In conclusion, it is expected that this method can be used for clinical auxiliary diagnosis and smart wearable devices in the future.

Electrocardiogram signal classification algorithm of nested long short-term memory network based on focal loss function / 生物医学工程学杂志

Electrocardiogram (ECG) can visually reflect the physiological electrical activity of human heart, which is important in the field of arrhythmia detection and classification. To address the negative effect of label imbalance in ECG data on arrhythmia classification, this paper proposes a nested long short-term memory network (NLSTM) model for unbalanced ECG signal classification. The NLSTM is built to learn and memorize the temporal characteristics in complex signals, and the focal loss function is used to reduce the weights of easily identifiable samples. Then the residual attention mechanism is used to modify the assigned weights according to the importance of sample characteristic to solve the sample imbalance problem. Then the synthetic minority over-sampling technique is used to perform a simple manual oversampling process on the Massachusetts institute of technology and Beth Israel hospital arrhythmia (MIT-BIH-AR) database to further increase the classification accuracy of the model. Finally, the MIT-BIH arrhythmia database is applied to experimentally verify the above algorithms. The experimental results show that the proposed method can effectively solve the issues of imbalanced samples and unremarkable features in ECG signals, and the overall accuracy of the model reaches 98.34%. It also significantly improves the recognition and classification of minority samples and has provided a new feasible method for ECG-assisted diagnosis, which has practical application significance.

QTc, Tp-e Interval and Tp-e/QTc Ratio in Patients with Hypocalcemia-case Control Study

Abstract Background: To the best of our knowledge, there are studies related to QT and QTc interval in patients with hypocalcemia, but there are no studies evaluating T wave peak and end interval (Tp-e interval), Tp-e/QT and Tp-e/QTc ratios used to evaluate cardiac arrhythmia risk and ventricular repolarization changes rates. Objectives: Therefore, we aimed to investigate whether there is a change in Tp-e interval, Tp-e/QT and Tp-e/QTc ratios in patients with hypocalcemia. Methods: Retrospectively, 29 patients with hypocalcemia in the emergency department were included in the study. Twenty-nine patients with similar age and sex distribution were included in the study as the control group. All patients underwent 12-lead electrocardiography (ECG). In addition to routine measurements, Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were measured on ECG. The study data were grouped as patients with and without hypocalcemia. Results: The mean age of the patients was 66.24 ± 4.95 years. QTc interval, Tp-e interval and Tp-e/QTc values were found to be significantly higher in patients with hypocalcemia (p <0.001 for each). QTc interval, Tp-e interval and Tp-e/QTc ratio showed a significant negative correlation with calcium levels. Conclusion: Tp-e interval and Tp-e/QTc ratios are significantly increased in patients with hypocalcemia compared to those without hypocalcemia and this can be used more effectively in the follow-up of cardiac fatal arrhythmias.

Idioventricular rhythm and shock after a honeybee sting / Ritmo idioventricular y shock después de un piquete de abeja

Abstract Objective: The objective of this study was to describe the case of a 19-year-old male presenting with bradycardia and hypotension after a honeybee sting making a review of the literature and pathophysiology of the cardiovascular and electrocardiogram (EKG) changes after a bee sting. Methods: The patient's airway was inspected and secured. Electrocardiogram with an idioventricular rhythm at 41' bpm. Oxygen was administered, an intravenous access was established, and the transcutaneous pacemaker leads were placed on the chest of the patient, then published guidelines management was induced. Results: The EKG showed idioventricular rhythm at a rate of 41 beats/min that resolved to a normal sinus rhythm after treatment. Conclusions: A full and prompt cardiovascular evaluation should be performed in all patients presenting to the emergency department after a bee sting, and published guidelines regarding the management of bradycardia and anaphylaxis should be followed to achieve successful outcomes.

Resumen Objetivo: Describir el caso de un paciente masculino de 19 años que presenta bradicardia e hipotensión después de una picadura de abeja haciendo una revisión de la literatura y fisiopatología de los cambios cardiovasculares y electrocardiográficos después de una picadura de abeja. Métodos: Se inspeccionó y aseguró la vía aérea del paciente. Un rastreo de ECG realizado al ingreso reveló ritmo idioventricular a una ritmo de 41 latidos por minuto. Se administró oxígeno, se estableció un acceso IV y se colocaron los cables del marcapasos transcutáneo en el tórax del paciente, luego se indujo el manejo de las guías publicadas. Resultados: El electrocardiograma mostró un ritmo idioventricular a una frecuencia de 41 latidos por minuto que se resolvió a un ritmo sinusal normal después del tratamiento. Conclusiones: Se debe realizar una evaluación cardiovascular completa y rápida en todos los pacientes que se presentan al departamento de emergencias después de una picadura de abeja, y se deben seguir las pautas publicadas sobre el manejo de la bradicardia y la anafilaxia para lograr resultados exitosos.

A new ECG sign for sudden death: Transient prolonged QT interval following premature contraction / 中南大学学报(医学版)

Early recognition and treatment for early warning electrocardiogram (ECG) of sudden death are very important to prevent and treat malignant arrhythmia and sudden death. Previous studies have found that R-on-T and T wave alternation, and QT interval prolongation are closely related to malignant arrhythmia or sudden death, which are included in the critical value of ECG.By analyzing the ECG characteristics of 4 patients with sudden death, we found that although the causes of the patients were different, there were transient prolongation of QT interval after premature contraction in 12 lead ECG, followed by malignant arrhythmia or sudden death. Thus, we thought that the transient prolongation of QT interval after premature contraction had a high value for warning malignant arrhythmia or sudden death. This phenomenon should be paid enough attention to reduce the risk of sudden death.

Value of Non-invasive Electrocardiologic Examination in Prediction of Sudden Cardiac Death / 中国医学科学院学报

Sudden cardiac death(SCD),a serious public health problem facing China and the world,causes heavy social burden.It is reported that SCD accounts for 15%-20% of all the deaths and the proportion of SCD patients with non-cardiac disease is as high as 50%.Finding effective predictors to identify SCD early is particularly important for clinical practice.To date,non-invasive electrocardiologic examination has been the first choice for predicting the risks of fatal ventricular arrhythmias and SCD because of its safety and feasibility.This review summarizes the available relevant studies to expound the value of non-invasive electrocardiologic examination and indicators in predicting SCD.

Evaluación y validación diagnóstica de las variables iQT, razón iQTRR, razón iRTRR para el diagnóstico DEQTc prolongado / Validation of iQT, iQTRR, iRT/RR ratio for estimation of QTc

ANTECEDENTES: El intervalo QT representa la despolarización y repolarización ventricular y su prolongación está asociada a un mayor riesgo de arritmias graves y muerte súbita. Depende de la frecuencia cardíaca y su rápida valoración es difícil de obtener en la práctica clínica. Una forma que facilita este proceso es medir sólo el intervalo QT pero este no siempre se relaciona con un intervalo QTc prolongado. Debido a esto, se postula que una variable compuesta debería tener mejor rendimiento diagnóstico para este objetivo. OBJETIVO: Describir la correlación de 3 variables electrocardiográficas; intervalo QT (iQT), razón del intervalo QT intervalo RR (%iQTRR) y razón del intervalo RT intervalo RR (%iRTRR), en relación a la variable QT corregido (iQTc). Se efectuó una evaluación diagnóstica y validación de las variables mencionadas para establecer el diagnóstico de intervalo QT largo y las propiedades diagnósticas de las mismas para el diagnóstico de iQTc prolongado según la fórmula Bazett. METODOS Y RESULTADOS: Se efectuó un estudio transversal descriptivo-relacional, usando una muestra no probabilística formada por 220 electrocardiogramas registrados en la base de datos del centro cardiovascular. Las mediciones provenían de ECGs registrados en reposo con medición con cáliper de los intervalos QT y RR en derivadas D2 y/o V5, expresadas en milisegundos. Se excluyó la presencia de isquemia, preexcitación y repolarización precoz. Se obtuvo como resultado que la variable razón iQTRR tiene mejor correlación, concordancia, sensibilidad y valor predictivo negativo para el diagnóstico del iQTc prolongado, versus las variables iQT y razón iRTRR, principalmente en mujeres. CONCLUSIONES: La variable razón iQTRR tiene una mejor correlación, concordancia, sensibilidad y valor predictivo negativo (VPN) para el diagnóstico del iQTc prolongado, comparado con las variables iQT y razón iRTRR, principalmente, en mujeres. Utilizando ambas variables este efecto se potencia y permite concluir que si una mujer tiene un iQT observado <470 ms, y una razón QTRR< 47,5%, esto se corresponde con un intervalo QTc normal, con un VPN de 100% .

BACKGROUND: The QT interval (QT) includes depolarization and repolarization phases of cardiac cycle. Its prolongation is associated to an increa sed risk of serious arrhythmia and sudden death. QT depends on heart rate and it is usually corrected using the Bazett formula (QTc). Prolonged QT is not usually well related to QTc. We postulate that a composite formula muy have a greater value for predicting serious arrhythmia. AIM: To correlate the predictive value of a different approach to estimate a corrected QT interval: the ratio of RT to RR intervals (QT/RR, expressed as a percentage METHODS and RESULTS: A non probabilistic sample of 220 ECGs were obtained from our data base. ECGs were recorded at rest and measurements were performed in leads Ds and/or V5 using zetcalipers, the values being expressed in ms. The presence of ischemia, pre excitation and early repolarization were excluded. The QT/RR ratio showed better correlation, concordance, sensitivity, and negative predicted value with the usual QTc interval compared to QT alone or de RT/RR ratio, especially so in women.

A Gravidade da Doença Afeta os Parâmetros de Repolarização Ventricular em Pacientes com COVID-19 / Disease Severity Affects Ventricular Repolarization Parameters in Patients With COVID-19

Resumo Fundamento: Não há estudos avaliando o intervalo Tpico-Tfim (Tpe), a relação Tpe/QT e a relação Tpe/QTc para avaliar arritmias cardíacas em pacientes com COVID-19. Objetivo: Visamos investigar se há alterações nos intervalos QT, QTc e Tpe e nas relações Tpe/QT e Tpe/QTc em pacientes com COVID-19. Métodos: O estudo incluiu 90 pacientes com infecção por COVID-19 e 30 controles saudáveis pareados por sexo e idade. Foram aferidos os intervalos QT, QTc e Tpe e as relações Tpe/QT e Tpe/QTc. Os participantes incluídos no estudo foram divididos nos seguintes 4 grupos: controles saudáveis (grupo I), pacientes com COVID-19 sem pneumonia (grupo II), pacientes com COVID-19 e pneumonia leve (grupo III) e pacientes com COVID-19 e pneumonia grave (grupo IV). Significância estatística foi definida por valor p < 0,05. Resultados: Verificou-se que a frequência cardíaca basal, a presença de hipertensão e diabetes, a contagem de leucócitos, o nitrogênio ureico no sangue, a creatinina, o potássio, o aspartato aminotransferase, a alanina aminotransferase, o NT-proBNP, a proteína C reativa de alta sensibilidade, o dímero-D, a TncI-as, o intervalo Tpe, a relação Tpe/QT e a relação Tpe/QTc aumentaram do grupo I para o grupo IV e foram significativamente mais altos em todos os pacientes do grupo IV (p < 0,05). A pressão arterial sistólica, a hemoglobina e os níveis de cálcio eram menores no grupo IV e significativamente menores em comparação com os demais grupos (< 0,05). Os intervalos QT e QTc eram semelhantes entre grupos. Determinou-se que os níveis elevados de frequência cardíaca, cálcio, dímero-D, NT-proBNP e PCR-as eram significativamente relacionados a Tpe, Tpe/QT e Tpe/QTc. Conclusões: Em pacientes com COVID-19 e pneumonia grave, o intervalo Tpe, a relação Tpe/QT e a relação Tpe/QTc, que estão entre os parâmetros de repolarização ventricular, foram aumentados, sem prolongação dos intervalos QT e QTc. A partir deste estudo, não podemos definitivamente concluir que as alterações eletrocardiográficas observadas estão diretamente relacionadas à infecção por COVID-19 ou à inflamação, mas sim associadas a cenários graves de COVID-19, que podem envolver outras causas de inflamação e comorbidades.

Abstract Background: There is no study evaluating the Tpeak-Tend (Tpe) interval, Tpe/QT ratio, and Tpe/QTc ratio to assess cardiac arrhythmias in patients with COVID-19. Objective: We aimed to examine whether there is a change in QT, QTc, Tpe interval, Tpe/QT ratio, and Tpe/QTc ratio in patients with COVID-19. Methods: The study included 90 patients with COVID-19 infection and 30 age-and-sex-matched healthy controls. QT, QTc, Tpe interval, Tpe/QT ratio, and Tpe/QTc ratio were measured. The participants included in the study were divided into the following 4 groups: healthy controls (group I), patients with COVID-19 without pneumonia (group II), patients with COVID-19 and mild pneumonia (group III), and patients with COVID-19 and severe pneumonia (group IV). Statistical significance was set at p < 0.05. Results: It was found that baseline heart rate, presence of hypertension and diabetes, white blood cell count, blood urea nitrogen, creatinine, potassium, aspartate aminotransferase, alanine aminotransferase, NT-proBNP, high sensitive C reactive protein, D-dimer, hs-cTnI, Tpe, Tpe/QT, and Tpe/QTc increased from group I to group IV, and they were significantly higher in all patients in group IV (p < 0.05). Systolic-diastolic blood pressure, hemoglobin, and calcium levels were found to be lowest in group IV and significantly lower than in other groups (< 0.05). QT and QTc intervals were similar between groups. It was determined that increased heart rate, calcium, D-dimer, NT-proBNP and hs-CRP levels were significantly related to Tpe, Tpe/QT, and Tpe/QTc. Conclusions: In patients with COVID-19 and severe pneumonia, Tpe, Tpe/QT ratio, and Tpe/QTc ratio, which are among ventricular repolarization parameters, were found to be increased, without prolonged QT and QTc intervals. In this study, we cannot definitively conclude that the ECG changes observed are directly related to COVID-19 infection or inflammation, but rather associated with severe COVID-19 scenarios, which might involve other causes of inflammation and comorbidities. (Arq Bras Cardiol. 2020; 115(5):907-913)

Analysis of Conduction Intervals in Normal Electrophysiological Studies: Establishment of Reference Values the Brazilian Population

Abstract Background In the investigation of cardiac rhythm disorders, a normal electrophysiological (EPS) study is associated with a favorable prognosis. One of the normality criteria is established by conduction intervals within expected range. Objective To establish reference values in EPS for the intracavitary conduction intervals (PA, AH and HV) in a Brazilian population. Methods A retrospective cohort study of the first 1,500 patients submitted to EPS ablation was performed at Instituto de Cardiologia do Rio Grande do Sul, Brazil. The EPS was considered normal if the test was performed for diagnostic purpose; absence of induced arrhythmias; and conduction intervals within the expected range. The REDCap software was used for data collection and management, and the SPSS Statistics 22.0 used for data analysis. Continuous variables were compared with Student's t-test for independent samples and categorical variables with the chi-square test (X 2 ). Values of p ≤ 0.05 were considered significant. Results A total of 124 (8.3%) with EPS considered normal were included; mean age was 52 ± 21 years, and 63 were male. The mean values in milliseconds of PA, AH and HV were 23 ± 9, 88 ± 25 and 44 ± 7, respectively. The PA, AH, and HV percentile ranges were 13 - 25, 81-107 and 40 - 52, respectively. When the patients were divided into three age groups (1 to 18 years, 19 to 64 years and 65 or more), we observed that the group of older patients had significantly higher values of PA, AH and HV compared with younger patients. Conclusion This study showed that intracavitary conduction intervals in a sample of the Brazilian population were similar to previously published studies. Elderly patients tend to have higher values of intracavitary conduction intervals in EPS. Future studies including broader age ranges could enable the acquisition of more reliable and reproducible reference values. (Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0)

Research of Methods to Reduce Alarm Fatigue of Monitoring System / 中国医疗器械杂志

OBJECTIVE@#In order to solve alarm fatigue, the algorithm optimization strategies were researched to reduce false and worthless alarms.@*METHODS@#A four-lead arrhythmia analysis algorithm, a multiparameter fusion analysis algorithm, an intelligent threshold reminder, a refractory period delay technique were proposed and tested with collected 28 679 alarms in multi-center study.@*RESULTS@#The sampling survey indicate that the 80.8% of arrhythmia false alarms were reduced by the four-lead analysis, the 55.9% of arrhythmia and pulse false alarms were reduced by the multi-parameter fusion analysis, the 28.0% and 29.8% of clinical worthless alarms were reduced by the intelligent threshold and refractory period delay techniques respectively. Finally, the total quantity of alarms decreased to 12 724.@*CONCLUSIONS@#To increase the dimensionality of parametric analysis and control the alarm limits and delay time are conducive to reduce alarm fatigue in intensive care units.

Bradycardic and Antiarrhythmic Effects of the D-Limonene in Rats / Efeitos Bradicárdicos e Antiarrítmicos do D-Limoneno em Ratos

Abstract Background: D-limonene (DL) is a monoterpene and is the major component in the essential oil of citrus fruit. It presents antihyperglycemic and vasodilatation activities. Objectives: This study evaluated the cardiovascular effects and potential antiarrhythmic of DL in rats. Methods: Hemodynamic and electrocardiographic (ECG) parameters were measured in male Wistar rats, which under anesthesia had been cannulated in the abdominal aorta and lower vena cava and had electrodes subcutaneously implanted. In the in vitro approach, the heart was removed and perfused using the Langendorff technique. The significance level adopted was 5% (p < 0.05). Results: DL, in doses of 10, 20, and 40 mg/kg (i.v), produced intense and persistent bradycardia associated with hypotension. Bradycardia with prolonged QTc was observed in the ECG in vivo recording. In the in vivo model of arrhythmia induced by Bay K8644, DL (10 mg/kg) decreased the arrhythmia score from 15.33 ± 3.52 to 4.0 ± 2.64 u.a (p < 0.05, n = 4). In isolated perfused hearts, DL (10-3 M) promoted significant reductions in heart rate (from 228.6 ± 8.5 ms to 196.0 ± 9.3 bpm; p < 0.05) and left ventricular development pressure (from 25.2 ± 3.4 to 5.9 ± 1.8 mmHg; n = 5, p < 0.05). Conclusions: DL produces bradycardia and antiarrhythmic activity in rat heart.

Resumo Fundamento: O D-limoneno (DL) é um monoterpeno e o principal componente do óleo essencial de frutas cítricas. Ele apresenta atividades anti-hiperglicêmicas e vasodilatadoras. Objetivos: Este estudo avaliou os efeitos cardiovasculares e antiarrítmicos potenciais do DL em ratos. Métodos: Os parâmetros hemodinâmicos e eletrocardiográficos (ECG) foram mensurados em ratos Wistar machos que, sob anestesia, tiveram a aorta abdominal e a veia cava inferior canuladas e receberam eletrodos implantados subcutaneamente. Na abordagem in vitro, o coração foi removido e perfundido utilizando a técnica de Langendorff. O nível de significância adotado foi de 5% (p < 0,05). Resultados: DL, nas doses de 10, 20 e 40 mg/kg (i.v), produziu bradicardia intensa e persistente associada à hipotensão. A bradicardia com QTc prolongado foi observada no registro in vivo do ECG. No modelo in vivo de arritmia induzida por Bay K8644, DL (10 mg / kg) houve diminuição do escore da arritmia de 15,33 ± 3,52 para 4,0 ± 2,64 u.a (p < 0,05, n = 4). Em corações perfundidos isolados, o DL (10-3 M) promoveu reduções significativas na frequência cardíaca (de 228,6 ± 8,5 ms para 196,0 ± 9,3 bpm; p < 0,05) e na pressão desenvolvida do ventrículo esquerdo (de 25,2 ± 3,4 para 5,9 ± 1,8 mmHg; n = 5, p < 0,05). Conclusões: O DL produz bradicardia e atividade antiarrítmica no coração de ratos.

Importancia de las arritmias cardiacas inducidas por tioridazina en las edades geriátricas / Importance of the heart arrhythmias induced by thioridazine in geriatric ages

RESUMEN Introducción: la discapacidad mental, íntimamente relacionada con el incremento de la expectativa de vida, se considera uno de los problemas más graves que hay que enfrentar en la centuria recién iniciada. Esto trae consigo el aumento de la prescripción de agentes anti psicóticos, como la tioridazina, lo que tiende a convertirse en un problema de salud al causar arritmias y en ocasiones fatales. Aún no se conoce en qué grado estas alteraciones son responsables de algunas muertes súbitas ocurridas en personas que tomaban estos medicamentos. Objetivo: identificar cuáles son las alteraciones clínicas y electrocardiográficas en los pacientes que usan la tioridazina, como droga de elección en los trastornos psiquiátricos. Materiales y métodos: se realizó un estudio descriptivo, a los ancianos atendidos en el Servicio de Geriatría que ingieran tioridazina, en cualquier dosis. Durante al período de marzo del año 2017 hasta marzo del 2018. Resultados: predominaron los ancianos del sexo femenino y comprendido en las edades 60 y 74 años, con nivel de escolaridad secundario, lo que se correlacionó con la doble función de la mujer en la sociedad actual, y el elevado nivel de escolaridad de la ciudadanía cubana. Predominaron antecedentes de hipertensión arterial y diabetes, al igual las palpitaciones en relación a un aumento de los bloqueos del has de his, observados en los electrocardiogramas. No se presentaron fallecidos. Conclusiones: deben utilizarse dosis bajas del medicamento, por corto tiempo y bajo supervisión electrocardiográfica (AU).

ABSTRACT Introduction: mental incapacity, tightly related to the life expectancy increase, is considered one of the most serious problems to afford in the current century. It brings about the increase of the prescription of anti-psychotic agents, like thioridazine, tending to become a health problem because of causing arrhythmias that are occasionally life-threatening. It is still unknown in what level these alterations are responsible for several sudden deaths in persons who took these drugs. Objective: to identify which are the clinical and electrocardiographic alterations in patients using thioridazine as drug of choice in psychiatric disorders. Materials and methods: a descriptive study was carried out in all patients who attended the Geriatric Service taking thioridazine in any doses during the period from March 2017 to March 2018. Results: female elder people aged 60-74 years predominated, with secondary school scholarship, finding a relationship with the double function of women in the current society, and the high level of scholarship among Cuban citizen. Arterial hypertension and diabetes antecedents predominated, and also palpitations related to the increase of His bundle blockade observed in electrocardiograms. There were no deaths. Conclusions: low doses of the drug should be used for a short time and under electrocardiographic supervision (AU).

Registro unicéntrico de ablaciones de taquiarritmias cardíacas en pacientes pediátricos. Seguridad y eficacia / Single-center registry of ablations of arrhythmogenic substrates in pediatric patients. Safety and efficacy

Introducción: Las taquiarritmias en pediatría son uno de las principales motivos cardiológicos de consulta a la guardia. Durante el primer año de vida presentan una significativa morbi-mortalidad, por lo que el tratamiento farmacológico inmediato es fundamental para reducir la misma. Hasta los 3 años existe la posibilidad de curación espontánea en un porcentaje de éstos pacientes. La indicación de procedimientos de ablación durante los primero 4 años de vida se limita a casos refractarios al tratamiento antiarrítmico, dado que cuanto menor peso presenta el paciente, más pequeño es el corazón y más riesgoso es el mismo. Las taquicardias en pacientes con cardiopatía empeora el pronóstico de la misma. A pesar que el tratamiento farmacológico ha permitido el control de la gran mayoría de ellas, en muchos casos se requieren más de una droga antiarrítmica, con mayor exposición a efectos adversos, y en muchos otros se vuelven refractarias. En las últimas 3 décadas se ha desarrollado en forma exponencial el tratamiento de las taquiarritmias por medio de la ablación por radiofrecuencia o por frío (crioablación). Estos procedimientos han permitido obtener la curación de la mayor parte de las taquiarritmias en pediatría. En nuestro trabajo se evaluaron las indicaciones de dichos procedimientos en una población pediátrica, como así también la tasa de éxito, recurrencia, y la morbimortalidad tanto globalmente, como en cada arritmia (AU)

In children, tachyarrhythmias are one of the main reasons for cardiological consultation at the Department of Emergency. In the first year of life, they are associated with significant morbiditymortality and therefore, immediate drug treatment is essential up to 3 years of age. The indication of ablation procedures during the first 4 years of life is limited to patients refractory to antiarrhythmic treatment, since the lower weight of the patient, the smaller the heart and the riskier the intervention. In patients with heart disease, tachycardia worsens the prognosis. Although pharmacological treatment controls the vast majority of tachyarrhythmias, more than one antiarrhythmic drug is often required, leading to greater exposure to adverse effects, and many become refractory. Over the past three decades, treatment of tachyarrhythmias has developed exponentially with the advent of radiofrequency or cold ablation (cryoablation). These procedures have led to the cure of most tachyarrhythmias in children. Our study assessed the indications for these procedures in a pediatric population, as well as the success and recurrence rates, and morbidity both overall and of each arrhythmia episode (AU)

Evaluación de registros Holter durante 19 horas en el contexto de la teoría de la probabilidad / Evaluation of 19-hour Holter recordings in the context of probability theory

Resumen Introducción: Previamente se desarrolló una nueva metodología de ayuda diagnóstica para los registros Holter fundamentada en los sistemas dinámicos y la teoría de probabilidad, a partir de la información registrada en 21 horas. Objetivo: Evaluar la capacidad diagnóstica de esta metodología durante 19 horas, comparándola con los resultados convencionales del Holter y con los resultados del método matemático aplicado en 21 horas. Materiales y Métodos: fueron evaluados 80 casos de pacientes mayores a 20 años, 10 con registro Holter normal y 70 diagnosticados de forma convencional con diferentes patologías cardíacas. Se establecieron los rangos para las frecuencias cardíacas y de número de latidos por hora en 21 y 19 horas; luego, se calculó la probabilidad de ocurrencia de estos, lo que permitió diferenciar estados de normalidad y enfermedad aguda a partir de tres parámetros. Se comparó el diagnóstico físico-matemático con el diagnóstico convencional, tomado como Gold Standard. Resultados: De los casos normales, dos presentaron probabilidad menor o igual a 0,217 y ocho probabilidades mayores o igual a 0,304; ningún caso de enfermedad aguda presentó valores con probabilidad menor o igual a 0,217, mientras que todos presentaron valores mayores o iguales a 0,304, tanto para los registros Holter evaluados en 21 como en 19 horas. Conclusiones: Se confirmó la utilidad clínica de la metodología ante una reducción del tiempo de evaluación a 19 horas, obteniendo diagnósticos objetivos con base en la auto-organización matemática del fenómeno.

Abstract Background: a new method to help evaluate 21-hour holter recordings based on dynamic systems and the theory of probability was previously developed Aim: to evaluate the diagnostic value of this methodology in the analysis of 19 hr compared to conventional holter analysis over a 21-hr recording. Methods: the holter recordings of 80 subjects aged over 20 years old were analyzed. Ten subjects had a normal holter and 70 conventionally diagnosed as abnormal. Ranges for heart rate and number of beats in 21 or 19 hours were determined. The probability of their occurrence was calculated using 3 parameters. The mathematically derived diagnosis was compared to the clinical diagnosis, considered a gold standard. Results: Among normal cases the calculated probability was ≤ 0.217 in 2 cases and ≥0.304 in 8. No case with acute disease presented probability values ≤0.217; all had probability values ≥0.304, both in 21 and 19 hour recordings. Conclusion: the mathematical methodology described was clinically useful allowing a reduction in recording time from 21 to 19 hr. Clinical diagnosis may be inferred from the mathematical organization of a holter recording.

Evaluation of Galectin-3 and myocardial fibrosis in patients with hypertrophic cardiomyopathy / Avaliação de Galectina-3 e fibrose miocárdica em pacientes com cardiomiopatia hipertrófica

Background: Galectin-3 is the designation given to the protein that binds to ß-galactosides, expressed by activated macrophages and described as a cardiac fibrosis mediator. In hypertrophic cardiomyopathy (HCM), myocardial fibrosis is an independent predictor of adverse outcome; however, the association between Galectin-3 and myocardial fibrosis has not been studied in this cardiopathy. Objective: To evaluate the association of Galectin-3 and the presence of myocardial fibrosis in a patient with hypertrophic cardiomyopathy. Methods: Galectin-3 was measured in automated equipment using the Elisa technique in 100 participants divided into two groups: 50 patients with hypertrophic cardiomyopathy and 50 healthy control subjects. All patients with hypertrophic cardiomyopathy underwent magnetic nuclear resonance with the late enhancement technique to investigate myocardial fibrosis. For the statistical analysis, p values < 0.05 were considered statistically significant. Results: Galectin-3 levels were low and did not show significant differences between patients with hypertrophic cardiomyopathy and the control group,10.3 ± 3.1 ng/dL and 11.3 ± 2.6 ng/dL (p = 0.12) respectively. Myocardial fibrosis was a common finding and was identified in 84% (42/50) of patients with HCM, but no differences were observed between Galectin-3 levels when comparing patients with and without fibrosis, 10.3 ± 2.4 ng/dL and 10.1 ± 2.1 ng/dL (p = 0.59). Conclusion: The results did not show an association between Galectin-3 and myocardial fibrosis in patients with hypertrophic cardiomyopathy, suggesting that non-inflammatory mechanisms of myocardial fibrosis formation and cardiac remodeling are involved in this cardiopathy

Arritmias e alterações cardíacas no paciente cirrótico / Arrhythmias and cardiac alterations in the cirrhotic patient

No Brasil, a cirrose é um problema de saúde pública, que afeta aproximadamente 2 milhões de pessoas. As causas mais comuns são a doença hepática alcoólica, as hepatites virais e a doença hepática não alcoólica. A relação entre desordens cardíacas e hepatopatias é descrita na literatura, e a mais importante delas é o prolongamento do intervalo QT. A cirrose, independente de sua causa, é uma patologia frequentemente encontrada na população brasileira. Por este motivo, elucidar dados referentes às arritmias cardíacas em pacientes cirróticos é de grande importância dentro do estudo desta subpopulação. O objetivo deste artigo é fazer uma revisão de literatura com as informações referentes a epidemiologia, fisiopatologia, fatores de risco e prognóstico para as arritmias cardíacas em portadores de cirrose. (AU)

In Brazil, cirrhosis is a public health problem affecting approximately 2 million people. The most common causes are alcoholic liver disease, viral hepatitis, and non-alcoholic liver disease. The relationship between cardiac disorders and liver diseases is described in the literature, and the most important one is the QT interval prolongation. Cirrhosis, regardless of its causes, is a pathology that is frequently found in the Brazilian population. For this reason, elucidating data regarding cardiac arrhythmias in cirrhotic patients is of great importance within the study of this subpopulation. The aim of this article is to review the literature with information on the epidemiology, pathophysiology, risk factors, and prognosis for cardiac arrhythmias in patients with cirrhosis. (AU)