Estudio de cohortes para evaluar la prevalencia de QT prolongado y arritmias en pacientes críticos durante la primera fase de la pandemia por COVID-19 / Cohort study to assess the prevalence of prolonged QT and arrhythmias in critically ill patients during the early phase of the COVID-19 pandemic

Antecedentes y objetivo: Los pacientes con infección por SARS-CoV-2 pueden presentar afectación cardiovascular, incluyendo miocarditis, arritmias y prolongación del intervalo QT. Nuestro objetivo fue evaluar el impacto de la COVID-19 y su tratamiento en la repolarización ventricular y el desarrollo de arritmias en pacientes críticos. Material y métodos: Estudio de cohortes retrospectivo de pacientes críticos con infección confirmada por SARS-CoV-2 durante un periodo de 3meses. Se registraron los datos clínicos relevantes y el tratamiento específico administrado para la COVID-19. Se consideró QTc prolongado cuando medía ≥460ms en mujeres y ≥450ms en hombres. Se registró la incidencia y el tipo de arritmias durante el mismo periodo. Resultados: Se evaluaron 77 pacientes con una edad media de 62±13años: 20 mujeres y 57 hombres. El 60% de los pacientes eran hipertensos, el 52% presentaban un IMC>30 y el 70% desarrollaron fracaso renal agudo durante el ingreso. El 56% de los pacientes presentaron prolongación del QTc. El 44% presentaron algún tipo de arritmia durante su estancia en la UCI, siendo en el 21% arritmias auriculares. La mortalidad global fue del 53%, sin diferencias entre los pacientes con o sin QTc prolongado. Conclusiones: En nuestra serie, una elevada proporción de pacientes críticos con COVID-19 han presentado QTc prolongado y arritmias. Los factores implicados se han relacionado con la elevación de biomarcadores cardiacos, la propia afectación miocárdica del virus y la medicación concomitante recibida en la UCI.(AU)

Introduction and objective: Patients with SARS-CoV-2 infection may present cardiovascular involvement including myocarditis, arrhythmias and QT interval prolongation. Our objective was to evaluate the impact of COVID-19 and its treatment on ventricular repolarization and development of arrhythmias in critically ill patients. Material and methods: Retrospective cohort study of critically ill COVID-19 patients during a 3-month period in whom at least one ECG was available. Relevant clinical data and specific treatment administered for COVID-19 were recorded. Prolonged QTc was considered prolonged when it measured ≥460ms in women and ≥450ms in men. The incidence and type of arrhythmias during the same period were recorded. Results: A total of 77 patients with a mean age of 62±13years, 20 women and 57 men, were evaluated. Sixty percent of the patients were hypertensive, 52% had a BMI>30, and 70% developed acute renal failure during admission. Some 56% of the patients presented QTc prolongation. Forty-four percent presented some type of arrhythmia during their stay in the ICU, 21% of which were atrial arrhythmias. Overall mortality was 53%, with no differences between patients with or without prolonged QTc. Conclusions: In our series, a high proportion of critical patients with COVID-19 presented prolonged QTc and arrhythmias. The factors involved have been related to the elevation of cardiac biomarkers, the myocardial involvement of the virus and concomitant medication received in the ICU.(AU)

Cohort study to assess the prevalence of prolonged QT and arrhythmias in critically ill patients during the early phase of the COVID-19 pandemic.

INTRODUCTION: Patients with SARS-CoV-2 infection may present cardiovascular involvement including myocarditis, arrhythmias and QT interval prolongation. Our objective was to evaluate the impact of COVID-19 and its treatment on ventricular repolarization and development of arrhythmias in critically ill patients. METHODS: Retrospective cohort study of critically ill COVID-19 patients during a 3-month period in whom at least one ECG was available. Relevant clinical data and specific treatment administered for COVID-19 were recorded. Prolonged QTc was considered prolonged when it measured ≥ 460 ms in women and ≥450 ms in men. The incidence and type of arrhythmias during the same period were recorded. RESULTS: A total of 77 patients with a mean age of 62 ±â€¯13 years, 20 women and 57 men, were evaluated. Sixty percent of the patients were hypertensive, 52% had a BMI > 30, and 70% developed acute renal failure during admission. Some 56% of the patients presented QTc prolongation. Forty-four percent presented some type of arrhythmia during their stay in the ICU, 21% of which were atrial arrhythmias. Overall mortality was 53%, with no differences between patients with or without prolonged QTc. CONCLUSIONS: In our series, a high proportion of critical patients with COVID-19 presented prolonged QTc and arrhythmias. The factors involved have been related to the elevation of cardiac biomarkers, the myocardial involvement of the virus and concomitant medication received in the ICU.

QTc interval prolongation in liver cirrhosis with upper gastrointestinal bleeding

QTc interval prolongation is common in patients with liver cirrhosis. Cirrhotic patients suffering from complications could also prolong QT interval. We aimed to explore the role of QTc interval prolongation in cirrhotic patients with upper gastrointestinal bleeding (UGIB). Overall, 167 patients were analyzed. QTc interval prolongation presented in 111 patients (66.5%). One hundred and seven patients (64.1%) suffered from acute UGIB. Results showed that RBC, Hb, ALB and calcium (Ca) were significantly lower, and DBIL, GGT, APTT, Child–Pugh score, MELD score and ALBI score were significantly higher in the prolongation group than those without QTc prolongation. AUROC of QTc was .699 (95%CI: .623–.768). In the acute UGIB subgroup, AUROC of QTc was .478 (95%CI: .347–.611). In the HBV subgroup, AUROC of QTc was .722 (95%CI: .616–.812). QTc interval prolongation was prevalent in cirrhotic patients with UGIB and correlated with liver dysfunction. QTc might not be a valid predictor of in-hospital mortality. (AU)

La prolongación del intervalo QTc es común en pacientes con cirrosis hepática. Los pacientes cirróticos que sufrieron complicaciones también podrían prolongar el intervalo QT. Nuestro objetivo fue explorar el papel de la prolongación del intervalo QTc en pacientes cirróticos con hemorragia digestiva alta (UGIB). En total, se analizaron 167 pacientes. La prolongación del intervalo QTc se presentó en 111 pacientes (66,5%). 107 pacientes (64,1%) padecían UGIB aguda. Los resultados mostraron que RBC, Hb, ALB y calcio (Ca) fueron significativamente más bajos, y DBIL, GGT, APTT, Child-Pugh score, MELD score y ALBI score fueron significativamente más altos en el grupo de prolongación que aquellos sin prolongación QTc. El AUROC de QTc fue de 0,699 (IC 95%: 0,623-0,768). En el subgrupo UGIB agudo, el AUROC de QTc fue 0,478 (IC 95%: 0,347-0,611). En el subgrupo de VHB, el AUROC de QTc fue 0,722 (IC 95%: 0,616-0,812). La prolongación del intervalo QTc fue prevalente en pacientes cirróticos con UGIB y se correlacionó con disfunción hepática. QTc podría no ser un predictor válido de mortalidad hospitalaria. (AU)

QTc interval prolongation in liver cirrhosis with upper gastrointestinal bleeding.

QTc interval prolongation is common in patients with liver cirrhosis. Cirrhotic patients suffering from complications could also prolong QT interval. We aimed to explore the role of QTc interval prolongation in cirrhotic patients with upper gastrointestinal bleeding (UGIB). Overall, 167 patients were analyzed. QTc interval prolongation presented in 111 patients (66.5%). One hundred and seven patients (64.1%) suffered from acute UGIB. Results showed that RBC, Hb, ALB and calcium (Ca) were significantly lower, and DBIL, GGT, APTT, Child-Pugh score, MELD score and ALBI score were significantly higher in the prolongation group than those without QTc prolongation. AUROC of QTc was .699 (95%CI: .623-.768). In the acute UGIB subgroup, AUROC of QTc was .478 (95%CI: .347-.611). In the HBV subgroup, AUROC of QTc was .722 (95%CI: .616-.812). QTc interval prolongation was prevalent in cirrhotic patients with UGIB and correlated with liver dysfunction. QTc might not be a valid predictor of in-hospital mortality.

Análisis de parámetros en señales electrocardiográficas de pacientes con Chagas y de variables del dominio del tiempo de la HRV usando polígrafo de alta resolución / Analysis of parameters in electrocardiographic signals of patients with Chagas and time domain variables of the HRV using high resolution polygraph / Análise de parâmetros em sinais eletrocardiográficos de pacientes com variáveis Chagas e de domínio do tempo da VFC utilizando polígrafo de alta resolução

Resumen Este trabajo presenta los resultados obtenidos de un estudio sobre el análisis de parámetros electrocardiográficos en registros de pacientes seropositivos a la enfermedad de Chagas del Departamento del Meta y medición de las variables en el dominio de tiempo de la variabilidad de la frecuencia cardiaca (HRV) y su comparación con registros de población de control. Se obtuvieron un total de 38 registros de 10 minutos en su gran mayoría (57,9%) con un polígrafo de alta resolución entre ambas poblaciones, creándose una base de datos anotada de éstos registros. El presente estudio, permitió encontrar diferencias significativas de parámetros electrocardiográficos para el intervalo QTc entre los grupos, que podría ser consecuencia de alteración de la condución cardiaca que se traduce en un mayor incremento del QTc, así como de afectación de las variables del dominio de tiempo de la Variabilidad de la Frecuencia Cardiaca (HRV), como la SDRR y SEHR, que resultan en valores más bajos para los pacientes seropositivos a enfermedad de Chagas. Se concluye que variables de los registros ECG y de la HRV, presentan alteración en pacientes con enfermedad de Chagas , que podrían ser utilizados como alertas tempranas de la enfermedad no diagnosticada serológicamente.

Abstract This paper presents the results obtained from a study on the analysis of electrocardiographic parameters in records of patients seropositive to Chagas disease of the Department of Meta and measurement of the variables in the time domain of heart rate variability (HRV) and its comparison with population control records. A total of 38 10-minute records were obtained in the vast majority (57,9%) with a high resolution polygraph between both populations, creating an annotated database of these records. The present study allowed us to find significant differences in electrocardiographic parameters for the QTc interval between the groups, which could be a consequence of an alteration of the cardiac conduction that translates into a greater increase in the QTc, as well as the affectation of the time domain variables of Heart Rate Variability (HRV), such as the SDRR and SEHR, which result in lower values ​​for HRV-positive patients with Chagas disease. It is concluded that variables from the ECG and HRV registries present an alteration in patients with Chagas disease, which could be used as early warnings of the serologically undiagnosed disease.

Resumo Este artigo apresenta os resultados obtidos em um estudo sobre a análise de parâmetros eletrocardiográficos em prontuários de pacientes soropositivos para a doença de Chagas do Departamento de Meta e mensuração das variáveis ​​no domínio do tempo da variabilidade da freqüência cardíaca (VFC) e sua comparação com os registros de controle populacional. Um total de 38 registros de 10 minutos foi obtido na grande maioria (57,9%) com um polígrafo de alta resolução entre as duas populações, criando um banco de dados anotado desses registros. O presente estudo permitiu encontrar diferenças significativas nos parâmetros eletrocardiográficos para o intervalo QTc entre os grupos, o que pode ser consequência de uma alteração da condução cardíaca que se traduz em maior aumento no QTc, bem como no comprometimento das variáveis ​​no domínio do tempo Variabilidade da Frequência Cardíaca (VFC), como o SDRR e o SEHR, que resultam em valores mais baixos para pacientes HIV positivos com doença de Chagas. Concluise que as variáveis ​​dos registros de ECG e HRV apresentam alteração nos pacientes com doença de Chagas, que pode ser utilizada como alerta precoce da doença sorologicamente não diagnosticada.

[QTc interval in the neonatal period in a Mexican population. A pilot study]. / Situación del intervalo QTc en el período neonatal en un hospital del occidente de México, estudio piloto.

INTRODUCTION: QT interval prolongation is associated with ventricular arrhythmias and sudden death syndrome. OBJECTIVE: To determine the value of QTc interval in healthy newborns in a general hospital in Jalisco, Mexico, and their outcome during their first months of life. METHODS: The study included healthy newborns from March to November 2016, in the Hospital General of Occidente in Jalisco, Mexico. A 12-lead electrocardiogram was performed at a speed of 25mm/s during the first 48h of life. The QT interval was measured in lead DII, and the QTc interval was calculated using the Bazett formula. Patients detected with QTc prolongation were assessed monthly with an ECG and echocardiogram. If they persisted with prolonged QTc interval, they were re-evaluated at 6 months with an ECG, 24h Holter, and electrocardiography study on parents and siblings. Those who persisted with prolonged QTc interval were evaluated with an ECG at 9 months. RESULTS: The study included 548 patients. The mean QTc interval at birth was 459 ms; during this period 33 patients has a QTc greated that 470 ms; which were evaluated monthly with a new electrocardiographic study, obtaining a mean QTc interal of 446 ms. At 6 months 16 patients were evaluated, with a mean QTc interval of 434ms. At 9 months, 6 patients were found to have a mean QTc interval of 438ms, and only 4 patients persisted with a prolonged QTc interval. CONCLUSIONS: The QTc interval in our population is prolonged compared to other populations and with a gradual return to normal.

Situación del intervalo QTc en el período neonatal en un hospital del occidente de México, estudio piloto / QTc interval in the neonatal period in a Mexican population. A pilot study

Resumen Introducción: La prolongación del intervalo QT se asocia con arritmias ventriculares y muerte súbita. Objetivo: Determinar el valor del intervalo QTc en recién nacidos sanos y evaluar su comportamiento durante los primeros meses de vida. Métodos: Recién nacidos sanos a término de marzo-noviembre 2016 en el Hospital General de Occidente del Estado de Jalisco, México. Se les practicó un electrocardiograma de 12 derivaciones a una velocidad de 25 mm/s durante las primeras 48 h. Se midió el intervalo QT en DII y se calculó el QTc mediante la fórmula de Bazett. Los pacientes a los que se detectó prolongación del QTc en sus primeras 48 h se valoraron al mes con ECG y ecocardiograma. Si persistieron con QTc alargado se revaloraron a los 6 meses con ECG, Holter de 24 h y estudio electrocardiográfico a padres y hermanos. Los que persistieron con QTc alargado se revaloraron a los 9 meses con ECG. Resultados: Se incluyeron 548 pacientes. La media del intervalo QTc al nacimiento fue de 459 ms; durante este período 33 pacientes presentaron un QTc mayor de 470 ms, los cuales fueron evaluados al mes mediante un nuevo estudio electrocardiográfico, obteniendo una media del intervalo QTc de 446 ms. A los 6 meses se evaluaron 16 pacientes, con una media del intervalo QTc de 434 ms. A los 9 meses se evaluaron 6 pacientes, con una media del intervalo QTc de 438 ms, y solo 4 pacientes persistieron con QTc prolongado. Conclusiones: El intervalo QTc en nuestros pacientes es más prolongado en comparación con otras poblaciones y muestra una normalización paulatina.

Abstract Introduction: QT interval prolongation is associated with ventricular arrhythmias and sudden death syndrome. Objective: To determine the value of QTc interval in healthy newborns in a general hospital in Jalisco, Mexico, and their outcome during their first months of life. Methods: The study included healthy newborns from March to November 2016, in the Hospital General of Occidente in Jalisco, Mexico. A 12-lead electrocardiogram was performed at a speed of 25 mm/s during the first 48 h of life. The QT interval was measured in lead DII, and the QTc interval was calculated using the Bazett formula. Patients detected with QTc prolongation were assessed monthly with an ECG and echocardiogram. If they persisted with prolonged QTc interval, they were re-evaluated at 6 months with an ECG, 24 h Holter, and electrocardiography study on parents and siblings. Those who persisted with prolonged QTc interval were evaluated with an ECG at 9 months. Results: The study included 548 patients. The mean QTc interval at birth was 459 ms; during this period 33 patients has a QTc greated that 470 ms; which were evaluated monthly with a new electrocardiographic study, obtaining a mean QTc interal of 446 ms. At 6 months 16 patients were evaluated, with a mean QTc interval of 434 ms. At 9 months, 6 patients were found to have a mean QTc interval of 438 ms, and only 4 patients persisted with a prolonged QTc interval. Conclusions: The QTc interval in our population is prolonged compared to other populations and with a gradual return to normal.

El análisis del intervalo QT corregido incrementa la capacidad de la ergometría para diagnosticar enfermedad arterial coronaria significativa / The Analysis of the Corrected QT-Interval Increases Exercise Stress Test Capability to Detect Significant Coronary Artery Disease

Introducción: La utilidad clínica de la capacidad de la ergometría para indicar la presencia y gravedad funcional de las obstrucciones coronarias se ve limitada por las relativamente bajas sensibilidad y especificidad del infradesnivel del segmento ST (infra-ST), lo cual hace necesaria la investigación de las modificaciones de otras variables electrocardiográficas durante el esfuerzo que puedan aportar información adicional y complementaria a la del infra-ST. Se ha demostrado que el evento más temprano en la primera fase de la lesión transmural es la prolongación del intervalo QT corregido (QTc). Objetivos: Investigar si las modificaciones del intervalo QTc inducidas por el esfuerzo máximo (QTc máx) sumadas al infra-ST ≥ 1 mm permiten incrementar la capacidad de la ergometría para diagnosticar la presencia de enfermedad arterial coronaria significativa y si otros signos pueden aportar también información útil para identificar a estos pacientes. Material y métodos: Ciento sesenta y seis pacientes con infra-ST ≥ 1 mm durante la fase de ejercicio y/o recuperación de una ergometría a los que posteriormente se les realizó una coronariografía se distribuyeron en dos grupos: Grupo I (GI): 118 pacientes que mostraron prolongación del intervalo QTc máx y Grupo II (GII): 48 pacientes que acortaron normalmente el QTc máx. Se analizaron parámetros clínicos, ergométricos y electrocardiográficos y la angiografía coronaria para comprobar la presencia de enfermedad arterial coronaria significativa. Resultados: En 102 de los 166 pacientes incluidos (61,4%) se diagnosticó enfermedad arterial coronaria significativa, todos ellos pertenecientes al GI. El GI mostró alta prevalencia de pacientes con enfermedad arterial coronaria significativa (86,4% vs. 0%; p < 0,001), bajo umbral isquémico, recuperación tardía del infra-ST, mayor ensanchamiento del complejo QRSmáx, incompetencia cronotrópica y baja tolerancia al ejercicio. Durante la prueba ergométrica graduada los pacientes del GII presentaron mayor prevalencia de hipertensión arterial grave y el infra-ST < 1 mm en el segundo minuto del posesfuerzo. El incremento del intervalo QTc máx resultó un predictor independiente de enfermedad coronaria (p < 0,001). Conclusiones: La prolongación del intervalo QTc máx sumado al infra-ST ≥ 1 mm incrementó notoriamente la capacidad de la prueba ergométrica graduada para diagnosticar la presencia de enfermedad arterial coronaria significativa, patología que estuvo ausente en todos los pacientes con infra-ST que acortaron normalmente el QTc máx.

Background: The clinical usefulness of exercise stress testing to indicate the presence and functional severity of coronary artery stenoses is limited by the relatively low sensitivity and specificity of ST-segment depression. Therefore, the modifications of other electrocardiographic variables during exercise, which may provide additional and complementary information to ST-segment depression, should be investigated. It has been demonstrated that the corrected QT interval (QTc) prolongation is the earliest event during the first stage of transmural ischemia. Objectives: The aim of this study was to investigate whether modifications of the QTc interval induced by maximal exercise (QTcmax) together with ST-segment depression ≥ 1 mm can increase the capability of the stress test to detect significant coronary artery disease and if other signs may also provide useful information to identify these patients. Methods: One hundred and sixty six patients with ST-segment depression ≥ 1 mm during exercise or during the recovery stage of a stress test underwent coronary angiography. They were divided into two groups: Goup I (GI): 118 patients with QTcmax interval prolongation and Group II (GII): 48 patients with normal QTcmax shortening. Clinical, stress test-related and electrocardiographic parameters and coronary angiography were analyzed to identify the presence of significant coronary artery disease. Results: Significant coronary artery disease was detected in 102 of the 166 patients included in the study (61.4%), all from GI. Group I showed high prevalence of patients with significant coronary artery disease (86.4% vs. 0%; p < 0.001), low ischemic threshold, late recovery of ST-segment depression, wider QRSmax complex, chronotropic incompetence and low exercise capacity. During graded exercise stress testing, GII patients presented greater prevalence of severe hypertension and ST-segment depression < 1 mm two minutes after exercise. Increased QTcmax interval resulted as an independent predictor of coronary artery disease (p < 0.001). Conclusions: QTcmax interval prolongation plus ST-segment depression ≥ 1 mm produced a considerable increase in the capability of exercise stress testing to detect significant coronary artery disease, which was absent in all the patients with ST-segment depression and normal QTcmax shortening.