Doble tormenta tiroidea y arrítmica en una gestante con múltiples taquicardias refractarias mediadas por un haz de kent intermitente ablacionado exitosamente

La tormenta tiroidea es un estado crítico y poco frecuente que condiciona la disfunción de múltiples órganos por el efecto del exceso de las hormonas tiroideas, esta disfunción endócrina tiene una elevada mortalidad y genera manifestaciones típicas como la taquicardia, fiebre, alteraciones gastrointestinales, cardiovasculares y del sistema nervioso central. El embarazo se ha asociado con un incremento en la incidencia de arritmias. Necesitan un tratamiento inmediato con drogas antiarrítmicas, cardioversión eléctrica o cesárea de urgencia. El WPW es una anormalidad cardiaca congénita que consiste en la presencia de un haz anómalo (Haz de Kent) que evita el sistema normal de conducción uniendo directamente aurículas y ventrículos. Veremos el caso de una gestante de 32 semanas que presenta un cuadro de tormenta tiroidea y múltiples episodios de taquicardia paroxística supraventricular (TPS), de tórpida y sombría evolución clínica mediada por un haz anómalo de Kent intermitente. Es evidente que la tormenta tiroidea en el contexto de la gestación produjo cambios en las propiedades electrofisiológicas del haz anómalo de Kent intermitente lo cual propició el desarrollo de múltiples taquicardias paroxísticas supraventriculares refractarias a la cardioversión eléctrica y farmacológica. Tampoco mejoró con la tiroidectomía total, solamente cedió por completo con la ablación por catéter de radiofrecuencia del haz anómalo de Kent.

Thyroid storm is a critical and infrequent state that conditions the dysfunction of multiple organs due to the effect of excess thyroid hormones. This endocrine dysfunction has a high mortality and generates typical manifestations such as tachycardia, fever, gastrointestinal, cardiovascular and heart disorders, and the central nervous system. Pregnancy has been associated with an increased incidence of arrhythmias. They need immediate treatment with antiarrhythmic drugs, electrical cardioversion, or emergency caesarean section. WPW is a congenital cardiac abnormality that consists of the presence of an abnormal bundle (Kent bundle) that prevents the normal conduction system, directly joining the atria and ventricles. We will see the case of a 32-week pregnant woman who presented symptoms of thyroid storm and multiple episodes of paroxysmal supraventricular tachycardia (PST), with a torpid clinical course mediated by an abnormal intermittent Kent bundle. It is evident that the thyroid storm in the context of pregnancy produced changes in the electrophysiological properties of the intermittent Kent bundle, which led to the development of multiple PST refractory to electrical and pharmacological cardioversion. Moreover, it also did not improve with total thyroidectomy, only resolved completely with radiofrequency catheter ablation of the Kent bundle.

Drug therapy and efficacy of heart failure caused by supraventricular tachycardia in infants / 中国小儿急救医学

Objective:To investigate the effect of drug therapy on heart failure caused by supraventricular tachycardia(SVT) in infants.Methods:Fifty-five infants with heart failure caused by SVT, including 24 boys and 31 girls, were treated at Beijing Children′s Hospital of Capital Medical University from January 2014 to December 2021.The drug treatment effects of heart failure caused by SVT were analyzed.Results:The average age of 55 infants at the first diagnosis was 5.8 months(1-11 months). All of them had heart failure, including three cases of atrial flutter, 23 cases of atrial tachycardia(13 cases of disordered atrial tachycardia and ten cases of monomorphic atrial tachycardia), and 29 cases of paroxysmal supraventricular tachycardia.Ultrasonic cardiogram showed that the left ventricular diameter increased and/or left ventricular systolic function decreased.Anti-heart failure therapy was effective in 55 cases(100.0%). Anti-arrhythmic drug therapy: atrial flutter and atrial tachycardia were mainly treated by controlling ventricular rate, digitalis combined with metoprolol was effective in 21 cases(80.8%, 21/26), digitalis alone was effective in four cases(15.4%, 4/26), and sotalol was effective in one case(3.8%, 1/26); paroxysmal supraventricular tachycardia was mainly treated with sinus rhythm conversion.The success rates of conversion were: ATP 20.7%(6/29), ATP combined with digitalis 26.1%(6/23), propafenone combined with digitalis 42.9%(3/7), amiodarone combined with digitalis 60.0%(3/5), and sotalol 92.9%(12/13). During follow-up period for 1 to 12 months, heart failure symptoms of all 55 cases(100.0%) improved, and ultrasonic cardiogram of 53 cases(96.3%)returned to normal.Conclusion:Anti-heart failure and anti-arrhythmic drugs for infants with heart failure caused by SVT need to be selected individually.Atrial tachycardia, especially disordered atrial tachycardia, is sensitive to digitalis.Sotalol can be used to treat refractory SVT.

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

Clinical profile of patients diagnosed with supraventricular tachycardia: a descriptive study at a tertiary care hospital

Background: Supraventricular tachycardia is a clinical syndrome characterized by a rapid tachycardia with an abrupt onset and termination.The objective ofour study was to determine andassess the clinical profile, electrocardiographic and echocardiographic of patients diagnosed with supraventricular tachycardia.Methods: This cross-sectional study was conducted in the department of general medicine, Dr DY Patil medical college and hospital, Navi Mumbai from April 2020 till October 2021, in which we included patients diagnosed with any type of supra-ventricular tachycardia and excluded hemodynamically unstable patients. Results:In the present study, of the 45 cases, atrial fibrillation was the most common mechanism of SVT, diagnosed in 47% of the patients. Next most common was AVNRT (22%) and AVRT (18%). In addition, atrial tachycardia was diagnosed in 9% of the patients and atrial flutter was diagnosed in 4%. Mean age of the patients was 34.5 years, ranging from 13 to 68 years and 56% were males. It was observed that palpitation was the most common symptoms (91%). On ECG, no abnormalities were detected in 64%, while left ventricular hypertrophy (18%) and prolonged corrected QT (18%) were the most common abnormalities.On echocardiography, no abnormality was detected in 78% of the patients. Furthermore, 49% of the patients achieved normal sinus rhythm with a single dose of adenosine infusion and 33% of the patients required another dose of adenosine infusion.Conclusions:Palpitation is common presentation symptom. Most of patients had good response to medication treatment especially adenosine therapy, additional treatment was required in few patients.

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.

Efficacy and influencing factors of Propafenone in acute treatment of paroxysmal supraventricular tachycardia in children / 中华实用儿科临床杂志

Objective:To explore the safety and efficacy of Propafenone in terminating paroxysmal supraventricular tachycardia (PSVT) in children and analyze the factors influencing the effectiveness.Methods:A retrospective study was conducted on 169 PSVT children treated with Propafenone in the Department of Pediatric Cardiology, Heart Center, the First Hospital of Tsinghua University from September 2014 to October 2021.There were 118 boys and 51 girls with an average age of (2.84±2.91) years (age range: 14 days-13 years). According to age, they were divided into ≤ 1-year-old group, >1-3-year-old group, >3-7-year-old group, and >7-year-old group.Mea-surement data were compared between groups using t-test and Mann- Whitney U test.Counting data were analyzed by χ2 test. Results:Among the 169 children with PSVT, 65 cases (38.5%) were below 1 year old, 47 cases (27.8%) were >1-3 years old, 40 cases (23.7%) were >3-7 years old, 17 cases (10.1%) were above 7 years old.About 24 cases (14.2%) were combined with congenital heart disease.A total of 153 cases (90.5%) had nonspecific symptoms at the first visit.A total of 4.1% (7/169 cases) were complicated with tachycardia-induced cardiomyopathy, and their left ventricular ejection fraction increased from (44.0±4.0)% to (53.7±6.9)% after successful control of PSVT ( t=-4.700, P=0.003). The complete termination of PSVT by intravenous Propafenone was achieved in 125 of 169 cases (74.0%, 125/169 cases). The complete termination rate after multiple times of administration (74.0%) was significantly higher than that after the first intravenous injection (53.3%, 90/169 cases) ( χ2=15.657, P<0.001). There was a significant difference regarding the complete termination rate between children ≤1 year old (60.0%, 39/65 cases) and those >1 year old (82.7%, 86/104 cases) ( χ2=10.696, P=0.001). For children ≤1 year old, 1.5 mg/kg Propafenone (51.1%, 23/45 cases) showed better efficacy for PSVT termination than 1.0 mg/kg Propafenone (20.0%, 4/20 cases) ( χ2=5.519, P=0.019). For children >1 year old, there was no significant diffe-rence between 1.5 mg/kg and 1.0 mg/kg Propafenone groups (57.9% vs.62.1%) ( χ2=0.180, P=0.671). The adverse reaction rate of intravenous Propafenone was 9.5% (16/169 cases). One case presented with severe hypotension, which occurred in a child with right cardiac insufficiency with tricuspid valve depression; 15 cases showed abnormal cardiac conduction and recovered spontaneously in a short time.There was no deterioration of cardiac function in children with mildly to moderately reduced cardiac function. Conclusions:It is relatively safe and effective to terminate PSVT in children with intravenous Propafenone.The complete termination rate is 74.0%, which is related to age, dose and times of administration.Despite of low incidence of side effects, Propafenone should not be used to treat PSVT with cardiac function which is significantly impaired or unclear secondary to persistent tachycardia.Special attention should be paid to cardiac function deterioration in these patients.

Catheter Ablation in Neonate with Heart Failure Due to Incessant Atrioventricular Reentrant Tachycardia

Abstract The atrioventricular (AV) reentrant tachycardia (AVRT) is the most common cause of supraventricular tachycardia (SVT) in the young pediatric population. Some newborns might present with congestive heart failure and require interventional treatment. Catheter ablation in small infants (<6 months and <5 kg) is still poorly performed and controversial due to high complications rate in this group of patients.1 We report a case of a 28 days old infant (3,5 kg) with a drug-refractory left accessory pathway mediated tachycardia and severe hemodynamic compromise, who underwent catheter ablation. Radiofrequency ablation should be part of the therapeutic arsenal in a context of drug-resistant supraventricular tachycardia with hemodynamic compromise, despite the greater risks of complications in this special population.

Evaluation of adenosine triphosphate in emergency cardioversion of paroxysmal supraventricular tachycardia in children / 中华实用儿科临床杂志

Objective:To explore the safety and efficacy of adenosine triphosphate (ATP) in terminating paro-xysmal supraventricular tachycardia (PSVT) in children and the correlation between its efficacy, age and dose.Methods:A retrospective analysis was performed on the clinical data, efficacy and adverse effects of intravenous ATP in 120 children who had received ATP emergency cardioversion among 1 488 children with PSVT hospitalized in the Department of Pediatric Cardiology, Heart Center, First Hospital of Tsinghua University from September 2014 to November 2019.There were 80 boys and 40 girls with the age of (3.50±3.66) years (25 d-15 years). As for the group comparison, the measurement data was subject to the independent samples t test and Mann- Whitney U test; the enumeration data was subject to χ2 test. Results:Among the 120 children with PSVT, there were 42 cases (35.0%) <1 year old, and 24 cases(20.0%) combined with congenital heart disease.There were 8.3% of them (10/120 cases) suffering from tachycardiomyopathy (TCM) secondary to PSVT, whose LVEF increased from (32.70±11.69)% to (40.50±11.63)% after successful control of PSVT ( t=-3.647, P=0.005). The complete termination of PSVT by intravenous ATP was achieved in 53 of 120 cases (44.2%). ATP was given at 0.3 mg/kg, 0.2 mg/kg and 0.1 mg/kg in dose, and the significant effective rate was 56.5%(13/23 cases), 36.4%(32/88 cases) and 0, respectively, which showed that there was a significant difference in the therapeutic effect between different dose groups ( χ2=10.058, P=0.007). There was a significant difference regarding the complete termination rate between children <1 year old and those ≥1 year old [31.0%(13/42 cases) vs.51.3%(40/78 cases), χ2=4.575, P=0.032]. For refractory PSVT, the intravenous ATP was performed based on the absence of cardioversion with continuous pumping of other antiarrhythmic drugs, which achieved a significantly complete termination rate of 55.6% (10/18 cases). The rate of ATP adverse reactions was 2.5%(3/120 cases), presented with sinus arrest in children >1 year old with the dose of 0.2-0.3 mg/kg. Conclusions:It was relatively safe and effective to terminate PSVT in children with ATP, which was related to dose and age.For refractory PSVT, ATP can be intravenously pushed on the basis of continuous pumping of other antiarrhythmic drugs, which can achieve a higher complete termination rate.

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.

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)

Diagnóstico diferencial de las taquicardias de complejo ancho: un desafío permanente / Wide QRS tachycardia: a diagnostic challenge

El diagnóstico electrocardiográfico correcto de la causa de una taquicardia de complejo QRS ancho (TCA) es fundamental, ya que tanto el manejo, como el pronóstico del paciente, es diferente según su etiología, y define el estudio que debemos realizar. Numerosos criterios y algoritmos han sido descritos para diferenciar el origen de estas taquicardias. Sin embargo, muchos de estos son complejos y difíciles de aplicar para el médico menos experimentado. Esto es particularmente importante en los servicios de emergencia, donde se necesita una definición rápida que permita un manejo agudo apropiado. En la presente revisión analizamos los diferentes mecanismos de las TCA y los principales criterios diagnósticos en el ECG, reforzando, especialmente, aquellos de aplicación rápida y de alto rendimiento diagnóstico.

The correct electrocardiographic diagnosis of the cause of a wide QRS complex tachycardia (WCT) is essential since both management and prognosis of the patient. The correct electrocardiographic diagnosis of the cause of a wide QRS complex tachycardia (WCT) is essential since both management and prognosis is different according to its etiology and defines the study that we should perform. Numerous criteria and algorithms have been described to differentiate the origin of these tachycardias. However, many of these are complex and difficult to apply to the less experienced doctor. This is particularly important in emergency rooms, where a rapid definition is needed to allow proper therapy. In this review we analyze the different mechanisms of WCT and the main EKG diagnostic criteria, emphasizing those which can be applied rapidly and have high diagnostic value.

Investigations for the assessment of adult patients presenting to the emergency department with supraventricular tachycardia / 世界急诊医学杂志（英文）

BACKGROUND@#Patients with supraventricular tachycardia (SVT) commonly present to the emergency department (ED). Current guidelines do not recommend routine pathology testing and a report on the topic has questioned their role. A systematic review concluded that troponin testing is commonly performed with a high proportion of positive findings, but these results were not associated with major adverse cardiac events. The conclusions of this review were limited by paucity of data and heterogeneity among studies.

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.

Rapid-onset supraventricular tachycardia following clozapine initiation and its management with verapamil: a case report

Clozapine is the drug of choice for treatment-resistant schizophrenia. However, the use of clozapine is limited by its serious adverse effects, which often underlie its discontinuation. The cardiovascular side effects that raise safety concerns include tachycardia, myocarditis and cardiomyopathy. The development of clozapine-induced tachycardia is usually observed on higher dosage especially at early stages of treatment. Here, author presented the case of a patient with treatment-resistant schizophrenia who developed asymptotic supraventricular tachycardia despite low dose of clozapine at the second day of treatment. Additionally, author explored the possibility of clozapine re-challenge in combination with verapamil treatment.

Application of transseptal puncture to radiofrequency catheter ablation in children with left accessory pathway induced paroxysmal supraventricular tachycardia / 中华实用儿科临床杂志

Objective To explore the value of transseptal puncture for left-sided accessory pathway in radio-frequency catheter ablation in children with paroxysmal supraventricular tachycardia(PSVT). Methods Thirty-three patients with PSVT who had underwent radiofrequency catheter ablation in the First Affiliated Hospital,Sun Yat-Sen University from January 2012 to December 2017 were retrospectively analyzed. All the cases were treated by transaortic approach(transaortic group)or transseptal approach(transseptal group). The immediate success rates,total fluoroscopy time and radiation exposure between 2 groups were compared,and the perioperative complications and recurrence rates were observed between 2 groups. Results Thirty-three cases of children were enrolled,22 cases were male and 11 cases were female. Nineteen cases were treated by transaortic approach(transaortic group),while 18 cases were treated by transseptal approach(transseptal group),including 4 recurrent cases in the transaortic group who were switched to transseptal approach because of previous treatment failure. The age was(10. 16 ± 3. 06)years and(10. 67 ± 2. 20) years,and the weight was(37. 68 ± 14. 28)kg and(37. 33 ± 8. 64)kg,respectively. There were no significant diffe-rences in age and weight statistics between 2 groups(all P>0. 05). The total fluoroscopy time was(20. 16 ± 11. 41) minutes and(12. 56 ± 5. 23)minutes,and the median dose of radiation exposure was 67. 0 mGy and 33. 5 mGy,re-spectively. The postoperative recurrence rate was 21%(4/19 cases)and 0(0/18 cases),respectively. There were sig-nificant differences in total fluoroscopy time,radiation exposure and recurrence rate statistics between 2 groups( t ＝2. 627,Z＝ -2. 31,χ2 ＝4. 249,all P<0. 05). No complications were found in both 2 groups. Conclusions It is safe and feasible by transseptal puncture for left-sided accessory pathway in radiofrequency catheter ablation in children with PSVT. Radiofrequency catheter ablation by transseptal approach could significantly reduce the postoperative recu-rrence rate,and should be the first choice for left-side accessory pathway in children.

Ablación de taquicardia supraventricular resistente a terapia médica y a cardioversión eléctrica en una gestante / Ablation of supraventricular tachycardia resistant to medical treatment and electrical cardioversion in a pregnant woman

Resumen Las arritmias cardiacas son complicaciones frecuentes durante el embarazo, y de hecho se ha considerado que este estado incrementa la incidencia de arritmias en pacientes con y sin enfermedad cardiaca estructural. El manejo de las arritmias en la paciente embarazada debe tener en cuenta no solo el bienestar materno sino el fetal, característica que restringe muchas de las terapias usadas en población no embarazada; sin embargo, es poco frecuente la falta de respuesta a terapia médica y cardioversión eléctrica. Se presenta el caso de una paciente gestante con taquicardia supraventricular por reentrada por vía accesoria sin respuesta a diferentes medidas farmacológicas y a varios intentos de cardioversión eléctrica, que requirió estudio electrofisiológico y ablación emergentes. Adicionalmente, se listan algunos aspectos claves sobre el tema.

Abstract Cardiac arrhythmias are common complications during pregnancy, and it appears that the incidence of arrhythmias has been increasing in patients with and without structural cardiac disease. The management of arrhythmias in the pregnant patient must not only take into account the well-being of the mother, but also that of the foetus, a fact that restricts many of the therapies used in the non-pregnant population. However, the lack of response to medical treatment and electrical cardioversion is rare. The case is presented of a pregnant patient with supraventricular re-entry tachycardia with no response to different pharmacological measures and to several attempts of electro-cardioversion that required an electrophysiological work-up and resulting ablation. Some key aspects on the subject are also mentioned.

A retrospective analysis of cardioversion for paroxysmal supraventricular tachycardia in emergency department / 中华急诊医学杂志

Objective To analyze retrospectively the cardioversion for paroxysmal supraventricular tachycardia (PSVT) in emergency department in order to explore rational guidance for the diagnosis and treatment for PSVT.Methods A retrospective analysis of PSVT patients in the emergency department admitted from June 2015 to December 2015 was carried out.First,all the patients were divided into two groups according to the cardioversion achieved by Valsalva's maneuvre or not.Forty patients were enrolled in study.There were 11 patients got cardioversion successfully achieved by the Valsalva's maneuvre and 29 patients failed to get cardioversion.Then,comparisons of demographics,vital sign,serum CTNI,potassium and NTproBNP level were carried out between these groups of patients using statistical analysis.The categorical variable was expressed in percentage and the continuous variable was described by mean±standard deviation and the comparisons of parameters were conducted by group t-test and chi-square test.Results The success rate of PSVT maneuvre cardioversion was 27.5％.In addition,there were no significant differences in demographics vital sign,TNI and NTproBNP between the two groups while there were significant differences in serum potassium level between the two groups [(3.8±0.4)mmol/L vs.(3.5±0.35)mmol/L P＜0.05].There was no significant difference in successful rate of cardioversion between the standard Valsalva's maneuvre(n=6) the modified Valsalva's maneuvre(n=5).The second-line treatment mainly included propafenone,adenosine,electroversion,verapamil and amiodarone.The propafenone was the most common second-line agent used for PSVT cardioversion accounting for 58.6％.Conclusions The success rate of Valsalva's maneuver cardioversion was low.Keeping properly a higher level of serum potassium could increase the success rate of cardioversion by Valsalva's maneuvre.