Characterization of cardiac arrhythmias and maternal-fetal outcomes in pregnant women: A prospective cohort study.

INTRODUCTION AND OBJECTIVES: Cardiovascular disease is a common cause of morbidity and mortality in pregnant women. Arrhythmias are common complications during pregnancy; however, the data are limited. Our goal was to characterize the epidemiology, clinical presentation, and impact of cardiac arrhythmias on maternal-fetal outcomes. METHODS: A prospective cohort study from the Colombian Registry of Pregnancy and Cardiovascular Disease was carried out from 2016 to 2019. All patients with tachyarrhythmia or bradyarrhythmia and a minimum follow-up of six months after delivery were included. The primary outcome was a composite of cardiac events defined as pulmonary edema, symptomatic sustained arrhythmia requiring specific therapy, stroke, cardiac arrest, or maternal death. Secondary outcomes were other cardiac, neonatal, and obstetric events. RESULTS: Arrhythmias were the most common cause of referral to our dedicated cardio-obstetric clinic. A total of 92 patients were included, mean age 27±6 years; 8.7% had previous structural heart disease, and cardiology consultation was delayed in 79.4%. The most common arrhythmias were premature ventricular contractions (33%) and paroxysmal reentrant supraventricular tachycardias (15%); 11 patients (12%) had cardiac implantable electronic devices. Cardiac events occurred in 18.4% of patients, obstetric events occurred in 6.5%, and one caesarean was indicated in the context of symptomatic severe mitral stenosis. Adverse neonatal outcomes were observed in 24.3% of newborns. CONCLUSIONS: Arrhythmias were the most common cause of referral to a dedicated cardio-obstetric clinic; most had a benign course. Adverse maternal cardiovascular outcomes were significant and there was a high rate of obstetric and neonatal adverse events, underlining the importance of multidisciplinary care.

Coumel tachycardia in children.

BACKGROUND: Coumel tachycardia is an infrequent form of supraventricular tachycardia (SVT) that usually occurs in infants and children. It is a tachycardia mediated by an accessory pathway with retrograde slow conduction that explains the classic ECG pattern with long RP' interval and negative P waves in leads II, III, and aVF. In this study, we describe the clinical course and management of Coumel tachycardia in children. CASE REPORT: We conducted a retrospective review of five consecutive pediatric patients, mean age 11 ± 3 years (range 6 to 14). The first episode of SVT was at a mean age of 10.4 ± 4.8 years (range 2 to 14) with a mean evolution of 7.4 ± 9.4 months (range 1 to 24). Pharmacological therapy was unsuccessful despite the combination of antiarrhythmic drugs. The tachycardia was incessant with a density > 85% by 24-hour Holter monitoring; one patient developed tachycardia-induced cardiomyopathy. All children underwent successful radiofrequency catheter ablation, mean 5 ± 3 applications (range 1 to 8) with a single session and with no complications. After a mean follow-up of 24 ± 16 months, all patients were asymptomatic and recurrence-free without antiarrhythmic treatment. CONCLUSIONS: Coumel tachycardia is clinically persistent and usually refractory to antiarrhythmic treatment with substantial risk of tachycardia-mediated cardiomyopathy. Catheter ablation is effective and safe in children; thus, it should be indicated promptly and based on individual selection.

INTRODUCCIÓN: La taquicardia de Coumel es una forma poco frecuente de taquicardia supraventricular que suele presentarse en lactantes. Es una taquicardia mediada por una vía accesoria de conducción lenta retrógrada que explica el patrón ECG clásico con intervalo RP' largo y ondas P negativas en las derivaciones II, III y aVF. En este trabajo se describe el curso clínico y el manejo de la taquicardia de Coumel en niños. CASO CLÍNICO: Se llevó a cabo una revisión retrospectiva de cinco pacientes pediátricos consecutivos, con una media de edad de 11 ± 3 años (intervalos 6 a 14). El primer episodio de taquicardia 10.4 ± 4.8 años con evolución de 7.4 ± 9.4 meses. El tratamiento farmacológico fue ineficaz a pesar de la combinación de antiarrítmicos. La taquicardia era incesante con una densidad > 85% por Holter-24h; un paciente desarrolló miocardiopatía inducida por taquicardia. Todos los niños fueron sometidos a ablación con catéter y radiofrecuencia con éxito, y un promedio de 5 ± 3 aplicaciones en una sola sesión y sin complicaciones. Después de un seguimiento de 24 ± 16 meses, todos los pacientes fueron asintomáticos y libres de recurrencia sin tratamiento antiarrítmico. CONCLUSIONES: La taquicardia de Coumel es clínicamente persistente y generalmente refractaria al tratamiento antiarrítmico con un riesgo sustancial de miocardiopatía mediada por taquicardia. La ablación con catéter es eficaz y segura en niños, por lo que debe indicarse de forma temprana y en lactantes de una selección individual.

Utilidad del Holter insertable con detección remota en el diagnóstico etiológico del ictus criptogénico: análisis de 73 pacientes / Use of the insertable Holter with remote detection in the etiological diagnosis of cryptogenic stroke: Analysis of 73 patients

Introducción El ictus criptogénico constituye el 25% del total de ictus isquémicos, de los cuales un 20-30% son debidos a fibrilación auricular (FA). Con el objetivo de aumentar la tasa de detección, surgen los dispositivos de monitorización prolongada implantables. El estudio del perfil del candidato ideal subsidiario de dicha monitorización otorgaría un mejor entendimiento de los mecanismos que subyacen en este subtipo de ictus. Objetivo Determinar qué variables están relacionadas y pueden predecir la detección de FA silente en pacientes con ictus criptogénico. Pacientes y métodos Se trata de una cohorte longitudinal con selección desde marzo de 2017 hasta mayo de 2022. Son pacientes portadores de dispositivo de monitorización implantable e ictus criptogénico con monitorización mínima de un año. Resultados El total de pacientes incluidos fue de 73, con edad media de 58,8 años, siendo el 56,2% varones. Se detectó FA en 21 pacientes (28,8%). Los factores de riesgo cardiovascular más frecuentes fueron hipertensión (47,9%) y dislipidemia (45,2%). La topografía más frecuente fue cortical (52%). En cuanto a los parámetros ecocardiográficos, un 22% tenían la aurícula izquierda dilatada, un 19% tenían foramen oval permeable y un 22% presentaron taquicardia supraventricular de alta densidad (>1%) en el Holter. En el análisis multivariante, la única variable predictora de FA es la presencia taquicardia supraventricular de alta densidad, con un área bajo la curva de 0,726 (IC 0,57-0,87, p=0,04), una sensibilidad del 47,6%, una especificidad del 97,5%, un valor predictivo positivo del 90,9%, un valor predictivo negativo del 78,8% y una exactitud del 80,9%. Conclusiones La presencia de taquicardia supraventricular de alta densidad puede ser orientativa para predecir FA silente. No se han observado otras variables que nos permitan predecir la detección de FA en estos pacientes (AU)

Introduction Cryptogenic stroke constitutes 25% of all ischemic strokes, of which 20–30% are due to atrial fibrillation (AF). With the aim of increasing the detection rate, implantable long-term monitoring devices have emerged. The study of the profile of the ideal candidate subsidiary to such monitoring would provide a better understanding of the mechanisms underlying this subtype of stroke. Objective To determine which variables are related and can predict the detection of silent AF in patients with cryptogenic stroke. Patients and methods This is a longitudinal cohort with recruitment from March 2017 to May 2022. They are patients with an implantable monitoring device and cryptogenic stroke with a minimum monitoring of one year. Result The total number of patients included was 73, with a mean age of 58.8 years, 56.2% were male. AF was detected in 21 patients (28.8%). The most frequent cardiovascular risk factors were hypertension (47.9%) and dyslipidemia (45.2%). The most frequent topography was cortical (52%). Regarding the echocardiographic parameters, 22% had a dilated left atrium, 19% had a patent foramen ovale, and 22% had high-density supraventricular tachycardia (>1%) on Holter monitoring. In the multivariate analysis, the only variable that predicts AF is the presence of high-density supraventricular tachycardia, with an area under the curve of 0.726 (CI 0.57–0.87, p=0.04), sensitivity of 47.6%, specificity of 97.5%, positive predictive value of 90.9%, negative predictive value of 78.8%, and accuracy of 80.9%. Conclusions The presence of high-density supraventricular tachycardia can be indicative for predicting silent AF. No other variables have been observed that allow us to predict detection of AF in these patients (AU)

Comportamiento del tiempo de conducción retrógrada al momento de la inducción de las taquicardias supraventriculares y su rol en el diagnóstico diferencial / Behavior of Retrograde Conduction Time at Supraventricular Tachycardia Induction and its Role in Differential Diagnosis

RESUMEN Antecedentes : El diagnóstico diferencial entre la taquicardia reentrante ortodrómica (TRO) y la taquicardia por reentrada nodal atípica (TRNa) puede ser dificultoso. Nuestra hipótesis es que las TRNa tienen más variabilidad en el tiempo de con ducción retrógrada al comienzo de la taquicardia que las TRO. Nuestros objetivos fueron evaluar la variabilidad en el tiempo de conducción retrógrada al inicio de la taquicardia en TRNa y TRO, y proponer una nueva herramienta diagnóstica para diferenciar estas dos arritmias. Métodos : Se midió el intervalo ventrículo-auricular (VA) de los primeros latidos tras la inducción de la taquicardia, hasta su estabilización. La diferencia entre el intervalo VA máximo y el mínimo se definió como delta VA (ΔVA). También contamos el número de latidos necesarios para que se estabilice el intervalo VA. Se excluyeron las taquicardias auriculares. Resultados : Se incluyeron 101 pacientes. Se diagnosticó TRO en 64 pacientes y TRNa en 37. El ΔVA fue 0 (rango intercuartílico, RIC, 0-5) milisegundos (ms) en la TRO frente a 40 (21-55) ms en la TRNa (p < 0,001). El intervalo VA se estabilizó significativamente antes en la TRO (1,5 [1-3] latidos) que en la TRNa (5 [4-7] latidos; p < 0,001). Un ΔVA < 10 ms diagnosticó TRO con 100% de sensibilidad, especificidad y valores predictivos positivo y negativo. La estabilización del intervalo VA en menos de 3 latidos predijo TRO con buena precisión diagnóstica. Los resultados fueron similares considerando sólo vías accesorias septales. Las TRN típicas tuvieron una variación intermedia. Conclusión : Un ΔVA < 10 ms es un criterio simple, que distingue con precisión la TRO de la TRNa, independientemente de la localización de la vía accesoria.

ABSTRACT Background : Differential diagnosis between orthodromic reentrant tachycardia (ORT) and atypical nodal reentrant tachy cardia (ANRT) can be challenging. Our hypothesis was that ANRT presents more variability in retrograde conduction time at tachycardia onset than ORT. Objectives : The objectives of this study were to assess retrograde conduction time variability at the start of tachycardia in ANRT and ORT, and postulate a new diagnostic tool to differentiate these two types of arrhythmias. Methods : The ventriculoatrial (VA) interval of the first beats after tachycardia induction was measured until stabilization. The difference between the maximum and minimum VA interval was defined as delta VA (ΔVA), and the number of beats needed for VA interval stabilization was also assessed. Atrial tachycardias were excluded. Results : In a total of 101 patients included in the study, ORT was diagnosed in 64 patients and ANRT in 37. ΔVA interval was 0 (interquartile range [IQR] 0-5) milliseconds (ms) in ORT vs. 40 (21-55) ms in ANRT (p <0.001). The VA interval significantly stabilized earlier in ORT (1.5 [1-3] beats) than in ANRT (5 [4-7] beats) (p<0.001). A ΔVA <10 ms diagnosed ORT with 100% sensitivity, specificity, and positive and negative predictive values. Ventriculoatrial interval stabilization in less than 3 beats predicted ORT with good diagnostic accuracy. The results were similar considering only accessory septal pathways. Typical NRTs presented an intermediate variation. Conclusion : Presence of DVA <10 ms is a simple criterion that accurately differentiates ORT from ANRT, independently of the accessory pathway localization.

[Use of the insertable Holter with remote detection in the etiological diagnosis of cryptogenic stroke: Analysis of 73 patients]. / Utilidad del Holter insertable con detección remota en el diagnóstico etiológico del ictus criptogénico: análisis de 73 pacientes.

INTRODUCTION: Cryptogenic stroke constitutes 25% of all ischemic strokes, of which 20-30% are due to atrial fibrillation (AF). With the aim of increasing the detection rate, implantable long-term monitoring devices have emerged. The study of the profile of the ideal candidate subsidiary to such monitoring would provide a better understanding of the mechanisms underlying this subtype of stroke. OBJECTIVE: To determine which variables are related and can predict the detection of silent AF in patients with cryptogenic stroke. PATIENTS AND METHODS: This is a longitudinal cohort with recruitment from March 2017 to May 2022. They are patients with an implantable monitoring device and cryptogenic stroke with a minimum monitoring of one year. RESULTS: The total number of patients included was 73, with a mean age of 58.8 years, 56.2% were male. AF was detected in 21 patients (28.8%). The most frequent cardiovascular risk factors were hypertension (47.9%) and dyslipidemia (45.2%). The most frequent topography was cortical (52%). Regarding the echocardiographic parameters, 22% had a dilated left atrium, 19% had a patent foramen ovale, and 22% had high-density supraventricular tachycardia (>1%) on Holter monitoring. In the multivariate analysis, the only variable that predicts AF is the presence of high-density supraventricular tachycardia, with an area under the curve of 0.726 (CI 0.57-0.87, p=0.04), sensitivity of 47.6%, specificity of 97.5%, positive predictive value of 90.9%, negative predictive value of 78.8%, and accuracy of 80.9%. CONCLUSIONS: The presence of high-density supraventricular tachycardia can be indicative for predicting silent AF. No other variables have been observed that allow us to predict detection of AF in these patients.

Coumel tachycardia in children / Taquicardia de Coumel en niños

Abstract Background: Coumel tachycardia is an infrequent form of supraventricular tachycardia (SVT) that usually occurs in infants and children. It is a tachycardia mediated by an accessory pathway with retrograde slow conduction that explains the classic ECG pattern with long RP' interval and negative P waves in leads II, III, and aVF. In this study, we describe the clinical course and management of Coumel tachycardia in children. Case report: We conducted a retrospective review of five consecutive pediatric patients, mean age 11 ± 3 years (range 6 to 14). The first episode of SVT was at a mean age of 10.4 ± 4.8 years (range 2 to 14) with a mean evolution of 7.4 ± 9.4 months (range 1 to 24). Pharmacological therapy was unsuccessful despite the combination of antiarrhythmic drugs. The tachycardia was incessant with a density > 85% by 24-hour Holter monitoring; one patient developed tachycardia-induced cardiomyopathy. All children underwent successful radiofrequency catheter ablation, mean 5 ± 3 applications (range 1 to 8) with a single session and with no complications. After a mean follow-up of 24 ± 16 months, all patients were asymptomatic and recurrence-free without antiarrhythmic treatment. Conclusions: Coumel tachycardia is clinically persistent and usually refractory to antiarrhythmic treatment with substantial risk of tachycardia-mediated cardiomyopathy. Catheter ablation is effective and safe in children; thus, it should be indicated promptly and based on individual selection.

Resumen Introducción: La taquicardia de Coumel es una forma poco frecuente de taquicardia supraventricular que suele presentarse en lactantes. Es una taquicardia mediada por una vía accesoria de conducción lenta retrógrada que explica el patrón ECG clásico con intervalo RP' largo y ondas P negativas en las derivaciones II, III y aVF. En este trabajo se describe el curso clínico y el manejo de la taquicardia de Coumel en niños. Caso clínico: Se llevó a cabo una revisión retrospectiva de cinco pacientes pediátricos consecutivos, con una media de edad de 11 ± 3 años (intervalos 6 a 14). El primer episodio de taquicardia 10.4 ± 4.8 años con evolución de 7.4 ± 9.4 meses. El tratamiento farmacológico fue ineficaz a pesar de la combinación de antiarrítmicos. La taquicardia era incesante con una densidad > 85% por Holter-24h; un paciente desarrolló miocardiopatía inducida por taquicardia. Todos los niños fueron sometidos a ablación con catéter y radiofrecuencia con éxito, y un promedio de 5 ± 3 aplicaciones en una sola sesión y sin complicaciones. Después de un seguimiento de 24 ± 16 meses, todos los pacientes fueron asintomáticos y libres de recurrencia sin tratamiento antiarrítmico. Conclusiones: La taquicardia de Coumel es clínicamente persistente y generalmente refractaria al tratamiento antiarrítmico con un riesgo sustancial de miocardiopatía mediada por taquicardia. La ablación con catéter es eficaz y segura en niños, por lo que debe indicarse de forma temprana y en lactantes de una selección individual.

Enterocolitis necrosante posterior a evento aislado de taquicardia supraventricular: reporte de un caso de presentación neonatal atípica / Necrotizing enterocolitis after an isolated event of supraventricular tachycardia. Case report of atypical neonatal presentation

La taquicardia supraventricular (TSV) es la principal taquiarritmia en el recién nacido (RN) que requiere una resolución urgente. Por su parte, la enterocolitis necrosante (ECN) es la emergencia gastrointestinal más común que afecta principalmente a RN prematuros. Aunque estas se reconocen como patologías distintas, la bibliografía sugiere que los episodios de TSV pueden predisponer a los pacientes a la ECN a través de alteraciones en el flujo sanguíneo mesentérico y una disminución de la perfusión tisular. Se presenta aquí el caso clínico de un neonato prematuro que desarrolló un cuadro de ECN luego de un evento aislado de TSV con bajo gasto cardíaco

Supraventricular tachycardia (SVT) is the main tachyarrhythmia in the newborn (NB) that requires urgent resolution. Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency that mainly affects premature infants. Although these conditions are recognized as distinct pathologies, literature reports suggest that episodes of SVT may predispose patients to NEC secondary to disturbances in mesenteric blood flow and a decrease in tissue perfusion. We present here the clinical case of a premature neonate who developed NEC after an isolated SVT event with low cardiac output

Taquicardia auricular macro-reentrante del tipo flutter auricular en paciente de dos meses infectado con SARS-CoV-2

Introducción: El 11 de marzo de 2020 se confirmaron los primeros casos de la enfermedad en Cuba. Objeto: Examinar una complicación de la infección por SARS-CoV-2 infrecuente en edad pediátrica y su tratamiento. Presentación del caso: Lactante de 2 meses de edad producto de un parto distócico por cesárea a las 41,5 semanas, procedente de la provincia de Guantánamo. Por condiciones maternas permaneció con su madre en el hospital durante 45 días. Egresa y a los 15 días en casa, consultan por fiebre de 38 ℃ durante tres días consecutivos. Se constata frecuencia cardiaca muy elevada y estado eutérmico. El test de antígeno y las pruebas de reacción en cadena de la polimerasa con transcriptasa inversa y PCR para SARS-CoV-2 fueron positivas, por lo que se ingresa en terapia intensiva pediátrica con impresión diagnóstica de taquicardia supraventricular que se define finalmente como flutter auricular. El tratamiento aplicado controló la arritmia cardiaca y contribuyó a su favorable evolución posterior. Conclusiones: Los hallazgos del examen físico y los datos en la anamnesis permiten realizar el diagnóstico del paciente en su etapa temprana. La fisiopatología de las complicaciones en niños está en la regulación local de la expresión de los receptores ACE2, aumento de la producción de catecolaminas y una mayor incidencia de toxicidad por medicamentos que producen lesión cardíaca aguda y arritmia, síntomas que pueden estar asociados con disfunción del sistema respiratorio y cambios hematológicos o no en la edad pediátrica.

Introduction: On March 11, 2020, the first cases of COVID-19 were confirmed in Cuba. Purpose: To examine a complication of SARS-CoV-2 infection uncommon in pediatric ages and its treatment. Case presentation: A 2-month-old infant from Guantánamo province was delivered by cesarean section at 41.5 weeks. Due to maternal conditions, the newborn remained with the mother in the hospital for 45 days. Then the newborn was discharged and after 15 days at home was evaluated due to fever of 38 ° C during three consecutive days. A very high heart rate and euthermic state were observed. The antigen test and reverse transcriptase polymerase chain reaction and PCR tests for SARS-CoV-2 were positive, so the newborn was admitted to the pediatric intensive care unit with diagnostic impression of supraventricular tachycardia that is finally defined as atrial flutter. The treatment applied controlled the cardiac arrhythmia and contributed to its subsequent favorable evolution. Conclusions: The findings of the physical examination and the data in the anamnesis allow the diagnosis of the patient in its early stage. The pathophysiology of complications in children is in the local regulation of ACE2 receptor expression, increased catecholamine production and an increased incidence of toxicity by drugs that produce acute cardiac injury and arrhythmia, symptoms that may be associated with dysfunction of the respiratory system and hematological changes or not in pediatric age.

Chiari network diagnosis intraoperative based on echocardiography.

We report a case of a Chiari network as a possible cause of intraoperative supraventricular tachycardia with potential cardiac flow obstruction and hemodynamic collapse. The intraoperative diagnostic analysis considered detects cardiac abnormalities associated to this congenital remnant and discard common intraoperative causes of hemodynamic alterations.

Chiari network diagnosis intraoperative based on echocardiography. / Diagnóstico intraoperatorio de red de Chiari basado en ecocardiografía.

We report a case of a Chiari network as a possible cause of intraoperative supraventricular tachycardia with potential cardiac flow obstruction and hemodynamic collapse. The intraoperative diagnostic analysis considered detects cardiac abnormalities associated to this congenital remnant and discard common intraoperative causes of hemodynamic alterations.

Validação de um Algoritmo Simples para Detecção de Taquicardia Ventricular no Eletrocardiograma / Validation of a Simple Electrocardiographic Algorithm for Detection of Ventricular Tachycardia

Resumo Fundamento O diagnóstico diferencial de taquicardia de QRS largo, entre taquicardia ventricular (TV) ou taquicardia supraventricular com condução aberrante (TSV-A) é algumas vezes difícil de ser feito na sala de emergência. Objetivo Avaliar a acurácia de um algoritmo novo e simples para a detecção de TV no eletrocardiograma (ECG) em pacientes com taquicardia de QRS largo. Métodos ECGs de 12 derivações para detecção de taquicardia de QRS largo foram obtidos prospectivamente de 120 pacientes durante estudo eletrofisiológico. Seis médicos com diferentes experiências analisaram os ECGs, e fizeram o diagnóstico com base no algoritmo D12V16, que envolve a análise da polaridade predominante do complexo QRS nas derivações I, II, V1 e V6. O diagnóstico foi comparado com os obtidos pelo algoritmo tradicional de Brugada e pelo estudo eletrofisiológico, o qual é considerado padrão ouro. Adotou-se um nível de significância de 5% (p<0,05) nas análises estatísticas. Resultados De acordo com o estudo eletrofisiológico, 82 ECGs eram de TV e 38 de TSV-A. Doenças cardíacas estruturais estavam presentes em 71 (86,6%) dos pacientes com TV e em oito (21,1%) com TSV-A. O algoritmo de Brugada teve uma maior sensibilidade global (87,2%), enquanto o algoritmo D12V16 apresentou maior especificidade global (85,1%) para TV. Tanto o algoritmo D12V16 como o de Brugada apresentou um alto valor preditivo positivo (90,9% vs. 85,8%, respectivamente) e acurácia similar (73,8% vs. 81,4%, respectivamente) para o diagnóstico de TV. Nos avaliadores experientes, a acurácia foi maior utilizando o algoritmo de Brugada que o algoritmo D12V16, mas a acurácia dos dois algoritmos foi similar segundo os avaliadores menos experientes. Conclusão O algoritmo simplificado pode ser um método útil para reconhecer TV no ECG, principalmente para médicos menos experientes. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0)

Abstract Background The differential diagnosis of wide QRS complex tachycardia (WCT) between ventricular tachycardia (VT) or supraventricular tachycardia with aberrant conduction (SVT-A) is sometimes difficult in the emergency room. Objective The aim of this study was to evaluate the accuracy of a new simple electrocardiographic algorithm to recognize VT in patients with wide complex tachycardia. Methods The 12-lead electrocardiograms (ECG) for WCT were prospectively obtained from 120 patients during electrophysiological study. Six physicians with different expertise analyzed the electrocardiographic recordings, and made the diagnosis based on the D12V16 algorithm, that involves the analysis of the predominant polarity of QRS in leads I, II, V1 and V6. The diagnosis was compared with that made using the traditional Brugada algorithm and the "gold-standard" electrophysiological study. Statistical analyses were performed with a significance level of 5% (p<0.05). Results According to the EPS study, 82 ECG recordings were VT and 38 SVT-A. Structural heart diseases were present in 71 (86.6%) patients with VT and in 8 (21.1%) with SVT-A. The Brugada algorithm had higher global sensitivity (87.2%), and the D12V16 algorithm had higher global specificity (85.1%) for VT. Both D12V16 and Brugada's algorithms presented a high positive predictive value (90.9% vs 85.8%, respectively) and similar accuracy (73.8% vs 81.4%, respectively) for the diagnosis of VT. Experienced evaluators were more accurate using Brugada algorithm than the D12V16 algorithm, but the accuracy of both algorithms was similar according to less experienced examiners. Conclusion The simplified algorithm may be a useful method to recognize VT in the ECG, especially for less experienced doctors. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0)

Disincronía ventricular inducida por fármacos y taquicardiomiopatía en un neonate / Drug-induced ventricular dissynchrony and tachycardiomyopathy in a newborn

Resumen La disfunción ventricular secundaria a disincronía eléctrica y mecánica es una complicación de la estimulación ventricular desde el ápex del ventrículo derecho. No existen informes de disincronía secundaria a los efectos de fármacos antiarrítmicos. Se presenta el caso de una niña de 10 días de vida con taquicardia supraventricular incesante que se internó en terapia intensiva neonatal. Se inició tratamiento con propranolol por vía oral y ante la persistencia de la taquicardia se agregó amiodarona endovenosa. La paciente estuvo predominantemente en taquicardia con frecuencias cardíacas entre 200 y 290 latidos por minuto durante una semana a pesar del tratamiento instaurado. La función ventricular fue normal en los ecocardiogramas realizados. Se agregó flecainida por vía oral al esquema de tratamiento y luego de 24 horas presentó una taquicardia más lenta con QRS ancho e imagen de bloqueo completo de rama izquierda. Un nuevo ecocardiograma evidenció deterioro de la función ventricular izquierda e insuficiencia mitral moderada lo que motivó la suspensión de la flecainida y el propranolol. A las 24 horas de la suspensión se observó la normalización de la función ventricular a pesar de la persistencia de episodios intermitentes de taquicardia. Se reinició el propranolol logrando el control de la taquicardia. La presencia de disincronía ventricular generada por el bloqueo de rama izquierda secundario al tratamiento farmacológico con flecainida constituye una novedosa explicación posible para el desarrollo de disfunción ventricular.

Abstract Ventricular dysfunction secondary to electrical and mechanical dyssynchrony in chronic right ventricular apical pacing is a well-recognized complication. There are no previous reports of pharmacologically induced dyssynchrony. A 10-day old infant with incessant supraventricular tachycardia was admitted to the neonatal intensive care unit. Therapy with oral propranolol was initiated and due to persistence of tachycardia intravenous amiodarone was administered. The patient remained predominantly in tachycardia with heart rates between 200-290 beats per minute for a week with serial echocardiograms showing preserved ventricular function. Oral flecainide was started. After 24 hours of treatment the patient developed a slower incessant wide QRS with a left bundle branch block pattern. The echocardiogram showed deterioration of left ventricular systolic function and moderate mitral regurgitation. Flecainide and propranolol were discontinued. The QRS complex narrowed and despite intermittent breakthroughs of supraventricular tachycardia, ventricular function normalized. Propranolol was restarted to achieve definitive control of the tachycardia. The presence of ventricular dyssynchrony generated by the left bundle branch block pattern secondary to pharmacological treatment with flecainide is a novel possible explanation for the development of ventricular dysfunction.

Assessment of the hemogram parameters in patients with paroxysmal supraventricular tachycardia: a retrospective study

SUMMARY OBJECTIVE: Inflammation has been suggested as a potential mechanism in the pathogenesis of arrhythmia. Hemogram parameters such as monocyte count to high-density lipoprotein cholesterol ratio (MHR), neutrophil/lymphocyte ratio (NLR), and monocyte/lymphocyte ratio (MLR) have been considered to be markers of inflammation and new cardiovascular risk predictors. This retrospective study aimed to investigate the relationship between MHR, NLR, and MLR in patients with paroxysmal supraventricular tachycardia (PSVT). METHODS: A retrospective study conducted at a university hospital in Bolu, Turkey, between 2017 and 2019. Our study included 196 patients who underwent electrophysiological study (EPS) due to palpitation or documented PSVT on electrocardiography (ECG). Patients having documented atrioventricular nodal re-entrant tachycardia (AVNRT) on ECG or inducible AVNRT on EPS were included in the PSVT group (n=130), and patients with palpitation but without inducible arrhythmia on EPS (n=66) were included in the control group. Routine biochemical and hemogram tests were performed before the EPS procedure. RESULTS: When hemogram parameters were compared, there was no statistically significant difference in MHR values [0.010 (0.001-0.030) vs 0.010 (0.001-0.020) p =0.67]. Additionally, both NLR [2.21(0.74-11.36) vs 1.98(0.72-24.87) p=0.13] and MLR [0.25 (0.03-1.05) vs 0.24(0.07-1.39) p=0.41] were not statistically significant between the two groups. CONCLUSION: There is no significant difference in PSVT patients regarding hemogram parameters including white blood cell subtypes, MLR, NLR, and MHR. Therefore the evaluation of hemogram parameters may not be clinically relevant for PSVT patients.

RESUMO OBJETIVO: A inflamação tem sido sugerida como um mecanismo potencial na patogênese da arritmia. Parâmetros do hemograma, como contagem de monócitos e razão de colesterol lipoproteína de alta densidade (MHP), proporção de neutrófilos / linfócitos (NLP) e proporção de monócitos / linfócitos (MLR), foram considerados marcadores de inflamação e novos preditores de risco cardiovascular. Este estudo retrospectivo teve como objetivo investigar a relação entre MHP, NLP e MLP em pacientes com taquicardia paroxística supraventricular (PSVT). MÉTODOS: Estudo retrospectivo realizado em um hospital universitário em Bolu, Turquia, entre 2017 e 2019. Nosso estudo incluiu 196 pacientes submetidos a estudo eletrofisiológico (EPS) devido a palpitações ou PSVT documentada na eletrocardiografia (ECG). Os pacientes com taquicardia nodal atrioventricular reentrante (AVNRT) no ECG ou AVNRT indutível no EPS foram incluídos no grupo PSVT (n = 130) e os pacientes com palpitações sem arritmia induzível no EPS (n = 66) foram incluídos no grupo controle. Testes bioquímicos e de hemograma de rotina foram realizados antes do procedimento de EPS. RESULTADOS: Quando os parâmetros do hemograma foram comparados, não houve diferença estatisticamente significante nos valores de MHP (0,010 (0,001-0,030) vs 0,010 (0,001-0,020) p = 0,67). Além disso, tanto o NLP (2,21 (0,74-11,36) vs 1,98 (0,72-24,87) p = 0,13) quanto o MLP (0,25 (0,03-1,05) vs 0,24 (0,07-1,39) p = 0,41) não foram estatisticamente significantes entre os dois grupos. CONCLUSÃO: Não há diferença significativa nos pacientes com PSVT em relação aos parâmetros do hemograma, incluindo os subtipos de glóbulos brancos, MHP, NLP e MHP. Portanto, a avaliação dos parâmetros do hemograma pode não ser clinicamente relevante para pacientes com PSVT.

Experiencia en el uso de propranolol para el tratamiento de la taquicardia supraventricular en pacientes menores de un año / Experience using propranolol for the management of supraventricular tachycardia in patients younger than 1 year

Objetivo. Evaluar los resultados y efectos adversos de la terapia con propranolol en menores de un año con taquicardia supraventricular. Población y métodos. Menores de 1 año con taquicardia supraventricular documentada, que recibieron tratamiento y prevención con propranolol por vía oral. Se analizaron sexo y edad, cardiopatía congénita asociada, pre excitación ventricular en el electrocardiograma basal, recurrencia intratratamiento y efectos adversos. Resultados. Se identificaron 107 pacientes. El primer episodio de taquicardia supraventricular ocurrió a una edad mediana de 190 días. En 10 pacientes, se observó cardiopatía congénita asociada. El 23,3 % presentó pre excitación ventricular en el electrocardiograma basal. El rango de la dosis de propranolol fue de 2 a 5 mg/kg/día. En el 30,8 %, se observó recurrencia intratratamiento. En 2 pacientes, se suspendió la medicación por efectos adversos graves. Conclusión. El propranolol evitó la recurrencia en el 70 % de los casos. En 2 pacientes, fue necesario suspenderlo por efectos adversos graves

Objective. To assess the results and adverse events of propranolol therapy in infants younger than 1 year with supraventricular tachycardia. Population and methods. Infants younger than 1 year with documented supraventricular tachycardia who received oral treatment and prophylaxis with propranolol. Sex and age, associated congenital heart disease, ventricular preexcitation in the base line electrocardiogram, on-treatment recurrence, and adverse events were analyzed. Results. A total of 107 patients were identified. The first supraventricular tachycardia event occurred at a median age of 190 days. Associated congenital heart disease was observed in 10 patients. Ventricular preexcitation in the baseline electrocardiogram was detected in 23.3 %. Propranolol dose ranged from 2 to 5 mg/kg/day. On-treatment recurrence was observed in 30.8 %. Medication was discontinued in 2 patients due to severe adverse events. Conclusion. Propranolol prevented recurrence in 70 % of cases. It was discontinued in 2 patients due to severe adverse events.

Resultado del tratamiento en pacientes sometidos a ablación percutánea por arritmias supraventriculares en la ciudad de Cuenca, periodo abril 2013- julio 2018 / Treatment outcome of percutaneous ablation in patients with supraventricular arrhythmias in Cuenca, April 2013- July 2018

INTRODUCCIÓN: Las taquicardias supraventriculares son comunes en la práctica clínica, a pesar de tener buen pronóstico, puede afectar significativamente la calidad de vida de los pacientes. El tratamiento médico no da como resultado la ausencia total de la arritmia, por lo que la terapia por ablación se ha convertido en el tratamiento de elección en muchos de los casos por su alto índice de éxito brindando una solución definitiva. El objetivo de este estudio es determinar la frecuencia de presentación de las principales taquicardias supraventriculares, distribuidas por edad y sexo, la frecuencia de éxito de la ablación percutánea y los factores relacionados con el mismo y la frecuencia de las complicaciones presentadas. MATERIALES Y MÉTODOS: Se realizó un estudio descriptivo transversal y de correlación, que incluyó 156 con diagnóstico de taquicardia supraventricular y ablacionados en los cinco centros hospitalarios en donde se realizó el procedimiento, basándonos en los registros clínicos de los mismos. RESULTADOS: De los 156 pacientes, 51.9% fueron mujeres y 48.1% hombres, con edades comprendidas entre los 10 y 80 años de edad. Las arritmias reportadas fueron taquicardia de reentrada nodal, taquicardia reentrante auriculoventricular y flutter auricular, de estas la más frecuente fue la taquicardia por reentrada auriculoventricular. El éxito global del tratamiento fue del 93.5%, sin reportar complicaciones, los factores relacionados estudiados no presentaron asociación estadísticamente significativa. CONCLUSIÓN: El tratamiento por ablación tuvo un alto porcentaje de éxito y una tasa nula de complicaciones, esto es un indicador tanto de eficacia como seguridad de este procedimiento.(au)

BACKGROUND: Supraventricular tachycardia is commonly diagnosed in clinical practice, despite having a good prognosis, it can significantly affect the patient's life quality. Pharmacological treatment does not result in the total absence of the arrhythmia, which is why ablation therapy has become the treatment of choice, due to its high success rate, and for offering a definitive solution. The aim of this study was to determine the frequency of each supraventricular tachycardia type, according to age and sex, the rate of success of percutaneous ablation and its related factors, and the frequency of complications due to the procedure. METHODS: A cross-sectional, descriptive, correlational study was conducted, including 156 patients diagnosed with supraventricular tachycardia and ablated, from five hospitals where the procedure was performed, based on their clinical records. RESULTS: From the 156 patients in this study, 51.9% were women and 48.1% men, the age ranged between 10 and 80 years. The most commonly reported arrhythmias were nodal reentrant tachycardia, atrioventricular reentrant tachycardia and atrial flutter, being the atrioventricular reentrant tachycardia the most frequent of all. The global success rate was 93.5%, no complications were reported, and none of the studied factors had significant statistical association with the success rate. CONCLUSION: Ablation treatment had a high success rate, with cero complications in this study, demonstrating the efficacy and safety of the procedure.(au)

Bloqueo de rama alternante en una taquicardia supraventricular: ¿Cuál es el mecanismo subyacente? / Alternating bundle branch block in a supraventricular tachycardia: Which is the mechanism ?

El bloqueo de rama funcional durante una taquicardia supraventricular puede ser observado con longitudes de ciclo cortas y representa una respuesta fisiológica del sistema de conducción intraventricular por la existencia de conducción nodal auriculo ventricular acelerada. Presentamos el caso de un paciente joven con taquicardia reentrante aurículo-ventricular ortodrómica y bloqueo de rama alternante. Esta respuesta infrecuente se explica por el hallazgo obtenido durante el estudio electrofisiológico. Una conducción nodal aurículo-ventricular acelerada produce un frente de onda que despolariza las ramas durante sus períodos refractarios. Una vez que ocurrió el bloqueo en una de las ramas, dicho bloqueo persistió debido al fenómeno de linking, que es por conducción oculta retrógrada repetitiva de la rama contralateral. Después de la ablación transcatéter de una vía accesoria oculta lateral izquierda, el marcapaseo auricular rápido a la misma longitud de ciclo de la taquicardia, reprodujo la misma aberrancia observada durante la taquicardia. Este procedimiento demostró que el bloqueo de rama funcional fue debido a la longitud de ciclo corto y no a la presencia de una vía accesoria aurículo-ventricular.

Functional bundle branch block during a supraventricular tachycardia can be observed with shorter cycle lengths and represent a physiologic response by the specialized intraventricular conduction system to accelerated AV nodal conduction. The present case corresponds to a young patient with exercise induced orthodromic A-V reentrant tachycardia and alternating bundle branch block. This unusual response is explained by the finding obtained during the electrophysiology study. An accelerated AV nodal conduction made the depolarizing wave front reach the bundle branches during their refractory period. Once block in one bundle was stablished, block persisted due to the linking phenomenon that is repetitive retrograde concealed conduction from the contralateral bundle. After catheter ablation of a concealed left-sided accessory A-V pathway, rapid atrial pacing at the same cycle length of the tachycardia reproduced the same aberrancies observed during tachycardia. This response proved that functional bundle branch block is due to the short cycle length and not the presence of an accessory A-V pathway.

Atrioventricular node reentrant tachycardia: Remote magnetic navigation ablation versus manual ablation - impact on operator fluoroscopy time.

INTRODUCTION AND AIMS: Remote magnetic navigation systems have demonstrated benefits in the ablation of difficult substrates. Their role in the ablation of atrioventricular nodal reentrant tachycardia (AVNRT), however, has only been studied in small patient series. The aim of this study was to compare the results of AVNRT ablation using magnetic navigation, in a center where every procedure is performed with this system, with manual ablation. METHODS: We selected 139 consecutive patients undergoing AVNRT ablation with magnetic navigation by a single operator between January 2009 and June 2016 and compared them to a group of 101 consecutive patients undergoing manual ablation in the same period by the same operator in another hospital. The methodology was the same in both groups. Success rates, complications, procedure time, radiofrequency time, total and operator fluoroscopy time, and recurrence rates were compared. RESULTS: There were no differences in success and complication rates. Procedure and total fluoroscopy times were not significantly different, but operator fluoroscopy time was significantly shorter with the magnetic navigation system (2.4±1.5 min vs. 7.2±4 min; p<0.001). The recurrence rate was higher in the manual group, although without statistical significance. CONCLUSIONS: The ablation of AVNRT with magnetic navigation is feasible using the same methodology as for manual ablation. Success and complication rates were similar. Operator fluoroscopy time was significantly less with the magnetic navigation system.