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.

Validation of qrs-polarity algorithm with special emphasis in parahisian pathways / Validación del algoritmo de la polaridad del qrs con especial énfasis en vías parahisianas

Abstract Background: In 1996 Iturralde et al. published an algorithm based on the QRS polarity to determine the location of the accessory pathways (AP), this algorithm was developed before the massive practice of invasive electrophysiology. Purpose: To validate the QRS-Polarity algorithm in a modern cohort of subjects submitted to radiofrequency catheter ablation (RFCA). Our objective was to determinate its global accuracy and its accuracy for parahisian AP. Methods: We conducted a retrospective analysis of patients with Wolff-Parkinson-White (WPW) syndrome who underwent an electrophysiological study (EPS) and RFCA. We employed the QRS-Polarity algorithm to predict the AP anatomical location and we compared this result with the real anatomic location determined in the EPS. To determine accuracy, the Cohen's kappa coefficient (k) and the Pearson correlation coefficient were used. Results: A total of 364 patients were included (mean age 30 years, 57% male). The global k score was 0.78 and the Pearson's coefficient was 0.90. The accuracy for each zone was also evaluated, the best correlation was for the left lateral AP (k of 0.97). There were 26 patients with a parahisian AP, who showed a great variability in the ECG features. Employing the QRS-Polarity algorithm, 34.6% patients had a correct anatomical location, 42.3% had an adjacent location and only 23% an incorrect location. Conclusion: The QRS-Polarity algorithm has a good global accuracy; its precision is high, especially for left lateral AP. This algorithm is also useful for the parahisian AP.

Resumen Antecedentes: En 1996 Iturralde y colaboradores publicaron un algoritmo basado en la polaridad del QRS para determinar la ubicación de las vías accesorias (VA), este algoritmo fue desarrollado antes de la práctica masiva de la electrofisiología invasiva. Objetivo: Validar el algoritmo de la polaridad del QRS en una cohorte moderna de sujetos sometidos a ablación con catéter por radiofrecuencia (ACRF). Nuestro objetivo fue determinar su precisión global y su precisión para las VA parahisianas. Métodos: Realizamos un análisis retrospectivo de pacientes con síndrome de Wolff-Parkinson-White (WPW) a los que se les realizó estudio electrofisiológico (EEF) y ACRF. Empleamos el algoritmo de la polaridad del QRS para predecir la ubicación anatómica de la VA y comparamos este resultado con la ubicación anatómica real determinada en el EEF. Para determinar la precisión se utilizaron el coeficiente kappa de Cohen (k) y el coeficiente de correlación de Pearson. Resultados: Se incluyeron un total de 364 pacientes (edad media 30 años, 57 % varones). La puntuación k global fue de 0,78 y el coeficiente de Pearson de 0,90. También se evaluó la precisión para cada zona, la mejor correlación fue para las VA laterales izquierdas (k de 0.97). Hubo 26 pacientes con VA parahisianas, que mostraron una gran variabilidad en las características del ECG. Empleando el algoritmo de la polaridad del QRS, el 34,6 % de los pacientes tenía una ubicación anatómica correcta, el 42,3 % tenía una ubicación adyacente y solo el 23 % una ubicación incorrecta. Conclusión: El algoritmo de la polaridad del QRS tiene una buena precisión global; su precisión es alta, especialmente para VA lateral izquierdo. Este algoritmo también es útil para la VA parahisiana.

Wolff-Parkinson-White Apresentado como QRS Alternante e Outros Diagnósticos Diferenciais em uma Grande Coorte de Triagem de ECG Pré-Participação / Wolff-Parkinson-White Presenting as QRS Alternans and Other Differential Diagnoses in a Large Pre-Participation ECG Screening Cohort

Resumo Fundamento A síndrome de Wolff-Parkinson-White (WPW) é uma condição pró-arrítmica que pode exigir restrição de atividades extenuantes e é caracterizada por sinais de ECG, incluindo ondas delta. Observamos casos de padrões intermitentes de WPW apresentando-se como QRS alternante ('WPW alternante') em uma grande coorte de triagem de ECG pré-participação de homens jovens que se candidataram ao recrutamento militar. Objetivos Nosso objetivo foi determinar o padrão de WPW alternante, as características do caso e a prevalência de outros diagnósticos diferenciais relevantes apresentando-se como alternância de QRS em um ambiente de pré-participação. Métodos Cento e vinte e cinco mil cento e cinquenta e oito recrutas militares do sexo masculino prospectivos foram revisados de janeiro de 2016 a dezembro de 2019. Uma revisão de prontuários médicos eletrônicos identificou casos de WPW alternante e padrões ou síndrome de WPW. A revisão de prontuários médicos eletrônicos identificou casos de diagnósticos diferenciais relevantes que podem causar alternância de QRS. Resultados Quatro indivíduos (2,2%) apresentaram WPW alternante em 184 indivíduos com diagnóstico final de padrão ou síndrome de WPW. Dois desses indivíduos manifestaram sintomas ou achados eletrocardiográficos compatíveis com taquicardia supraventricular. A prevalência geral de WPW alternante foi de 0,003%, e a prevalência de WPW foi de 0,147%. As WPW alternantes representaram 8,7% dos indivíduos com QRS alternantes, e QRS alternantes tiveram prevalência de 0,037% em toda a população. Conclusões A WPW alternante é uma variante da WPW intermitente, que compreendeu 2,2% dos casos de WPW em nossa coorte de triagem pré-participação. Não indica necessariamente um baixo risco de taquicardia supraventricular. Deve ser reconhecido na triagem de ECG e distinguido de outras patologias que também apresentam QRS alternantes.

Abstract Background Wolff-Parkinson-White (WPW) syndrome is a proarrhythmic condition that may require restriction from strenuous activities and is characterized by ECG signs, including delta waves. We observed cases of intermittent WPW patterns presenting as QRS alternans ('WPW alternans') in a large pre-participation ECG screening cohort of young men reporting for military conscription. Objectives We aimed to determine the WPW alternans pattern, case characteristics, and the prevalence of other relevant differential diagnoses presenting as QRS alternans in a pre-participation setting. Methods One hundred twenty-five thousand one hundred fifty-eight prospective male military recruits were reviewed from January 2016 to December 2019. A review of electronic medical records identified cases of WPW alternans and WPW patterns or syndrome. Reviewing electronic medical records identified cases of relevant differential diagnoses that might cause QRS alternans. Results Four individuals (2.2%) had WPW alternans out of 184 individuals with a final diagnosis of WPW pattern or syndrome. Two of these individuals manifested symptoms or ECG findings consistent with supraventricular tachycardia. The overall prevalence of WPW alternans was 0.003%, and the prevalence of WPW was 0.147%. WPW alternans represented 8.7% of individuals presenting with QRS alternans, and QRS alternans had a prevalence of 0.037% in the entire population. Conclusions WPW alternans is a variant of intermittent WPW, which comprised 2.2% of WPW cases in our pre-participation screening cohort. It does not necessarily indicate a low risk for supraventricular tachycardia. It must be recognized at ECG screening and distinguished from other pathologies that also present with QRS alternans.

Neonatal Ebstein's anomaly with type B Wolff-Parkinson-White syndrome: a case report / 中华围产医学杂志

This paper reported a male newborn with Ebstein's anomaly complicated by type B Wolff-Parkinson-White syndrome. The baby was delivered at 39 weeks of gestation and diagnosed as Ebstein's anomaly complicated by type B Wolff-Parkinson-White syndrome 2 d after birth. He was improved and discharged after conservative management in the Department of Internal Medicine. No abnormality was found by fetal echocardiography at 20 weeks of gestation, while supraventricular tachycardia was diagnosed by M-mode ultrasonography at 38 weeks of gestation due to rapid fetal heart rate. In addition to hemodynamic changes,the abnormal cardiac structure in patients with Ebstein's anomaly may also lead to tachyarrhythmia. Therefore, in fetuses diagnosed with supraventricular tachycardia by prenatal ultrasound or children with type B Wolff-Parkinson-White syndrome detected by electrocardiogram after birth, tricuspid valve should be carefully scanned under echocardiography to avoid the missed diagnosis of Ebstein's anomaly.

Orthodromic Atrioventricular Tachycardia in Wolff-Parkinson-White Syndrome with Two Accessory Pathways Participation during the Same AVT

Case report of a 49-year-old patient with Wolff-Parkinson-White syndrome, very symptomatic, with apparent parahisian pathway who, during an electrophysiological study, presented orthodromic atrioventricular tachycardia, featuring two accessory pathways, retrogradely, the parahisian pathway and a hidden left posterolateral pathway, during the same tachycardia, alternating the retrograde pathway of tachycardia without interruption.

Pathogenic Vibrio spp. identified for white syndrome coral disease in Tioman Island Marine Park, Malaysia

Aims@#Coral diseases have emerged over the last several decades, causing a loss of live coral cover in the Caribbean and Indo-Pacific reefs. Hence, microbiological and disease cultural techniques are commonly used to investigate their causative microbial agents. This is the first study to identify the potential of pathogenic Vibrio spp. isolated from apparently white syndrome (WS) coral disease in Tioman Island Marine Park using biochemical and molecular techniques. @*Methodology and results@#The Vibrio colonies were isolated from 108 samples of WS infected corals (Acropora cytherea and Montipora aequituberculata) including seawater, sediment and algae found adjacent to infected coral colonies. A total of one hundred representative Vibrio isolates were characterized and most of them (n=50) were identified as V. vulnificus, V. alginolyticus and Photobacterium damselae following biochemical analysis. The molecular analysis revealed six Vibrio spp. (V. coralliilyticus, V. hepatarius, V. brasiliensis, V. tubiashi, V. campbellii, V. ishigakensis) and one Photobacterium rosenbergii. Vibrio coralliilyticus isolated from all infected coral samples may be highly responsible for the sign of WS disease.@*Conclusion, significance and impact of study@#The findings of this study provide baseline data and information on potential coral pathogens identified in the coastal waters of Tioman Island. Etiological disease study is suggested to validate their severity and virulence factors in the future.

Patrón de Wolff-Parkinson-White en joven atleta de élite: Algoritmo a seguir / Wolff-Parkinson-White pattern in a young elite athlete: Algorithm to follow

RESUMEN El síndrome de Wolff-Parkinson-White es una cardiopatía no estructural poco frecuente que pertenece a los denominados síndromes de preexcitación ventricular. Está asociada al desarrollo de muerte súbita, pues puede inducir a la aparición de arritmias malignas y su diagnóstico puede establecerse a través de la realización de un electrocardiograma. En caso de presentarse en personas vinculadas a la práctica deportiva, con el desarrollo de ejercicio físico intenso, puede incrementar el riesgo de muerte súbita. Se describe el caso de un atleta de alto rendimiento con diagnóstico de síndrome de Wolf Parkinson White y se presentan las pautas a seguir, según los criterios internacionales para la interpretación del electrocardiograma en deportistas.

ABSTRACT Wolff-Parkinson-White syndrome is a rare and non-structural heart disease, which belongs to the ventricular preexcitation syndromes. It is associated with the development of sudden death, as it can induce the appearance of malignant arrhythmias in the patient and its diagnosis can be established through electrocardiogram. If it takes place in people linked to sport, with the development of intense physical exercise, it can increase the risk of sudden death. The case of a high-performance athlete with a diagnosis of Wolff-Parkinson-White syndrome is described, and the guidelines to be followed according to international criteria for the interpretation of the electrocardiogram in sportsmen and women are presented.

Analysis of clinical and electrophysiological characteristics of children with Wolff-Parkinson-White syndrome or ventricular pre-excitation / 中华实用儿科临床杂志

Objective@#To summarize the clinical and electrophysiological characteristics of children with Wolff-Parkinson-White syndrome or ventricular pre-excitation.@*Methods@#One hundred and seventy-nine consecutive children with Wolff-Parkinson-White syndrome or ventricular pre-excitation who were hospitalized at Beijing Anzhen Hospital Affiliated to Capital Medical University and planned to accept radiofrequency ablations were selected.Electrocardiogram and echocardiography were completed and detailed clinical data were collected before ablations.Anterograde refractory period of accessory pathways (ERPAPA) and retrograde ventriculoatrial conduction were measured during electrophysiology studies.The clinical and electrophysiological characteristics of these children were analyzed.@*Results@#The ratio of left-sided to right-sided accessory pathways was 1.001.93(61 cases vs.118 cases). Six out of 61 patients with left-sided accessory pathways were verified by electrophysiology study.There was no statistical difference of P-R interval and QRS duration between patients with right-sided and left-sided accessory pathways(all P>0.05). Twelve patients were combined with congenital heart diseases.Fourteen patients with right-sided accessory pathways were of ventricular pre-excitation induced dilated cardiomyopathy.ERPAPA was measured successfully in 110 patients, ERPAPA less than 250 ms accounted for 32.7%(36/110 cases). Six children with two pathways were recognized.Antidromic atrioventricular reentrant tachycardia was induced in 3 children.One child had slow conduction pathway localized in right-sided septum.@*Conclusions@#Right-sided overt accessory pathways are more common in children with Wolff-Parkinson-White syndrome or ventricular pre-excitation.Organic heart diseases are not uncommon.Besides congenital heart disease, a small proportion of patients with right overt accessory pathways may develop ventricular pre-excitatory induced dilated cardiomyopathy resulting from ventricular wall dyskinesia.Most of the decremental retrograde ventriculoatrial conduction is the characteristic of ventricular muscles rather than the accessory pathways in nature.Two pathways are not uncommon in children with Wolff-Parkinson-White syndrome or ventricular pre-excitation.Before finishing radiofrequency ablation, the anterograde and retrograde function of the accessory pathway should be evaluated in detail again because it is easy to neglect the existence of another accessory pathway.

Left ventricular noncompaction and pre-excitation: an unusual finding in adults

Left ventricular noncompaction (LVNC) is a rare form of cardiomyopathy characterized by prominent left ventricular (LV) trabeculae, deep intertrabecular recesses, and the thin compacted layer. The disease is potentially associated with sudden cardiac death due to LV dysfunction and ventricular arrhythmias. The presence of accessory pathway and Wolff-Parkinson-White syndrome is particularly rare in adults. Here we describe the rare association of LVNC and ventricular pre-excitation in an 18-year-old female with neonatal hypoxic brain injury (AU)

A Case of Multiple Cardiovascular and Tracheal Anomalies Presented with Wolff-Parkinson-White Syndrome in a Middle-aged Adult

Congenital cardiovascular anomalies, such as dextrocardia, persistent left superior vena cava (SVC), and pulmonary artery (PA) sling, are rare disorders. These congenital anomalies can occur alone, or coincide with other congenital malformations. In the majority of cases, congenital anomalies are detected early in life by certain signs and symptoms. A 56-year-old man with no previous medical history was admitted due to recurrent wide QRS complex tachycardia with hemodynamic collapse. A chest radiograph showed dextrocardia. After synchronized cardioversion, an electrocardiogram revealed Wolff-Parkinson-White (WPW) syndrome. Persistent left SVC, PA sling, and right tracheal bronchus were also detected by a chest computed tomography (CT) scan. He was diagnosed with paroxysmal supraventricular tachycardia (PSVT) associated with WPW syndrome, and underwent radiofrequency ablation. We reported the first case of situs solitus dextrocardia coexisting with persistent left SVC, PA sling and right tracheal bronchus presented with WPW and PSVT in a middle-aged adult. In patients with a cardiovascular anomaly, clinicians should consider thorough evaluation of possibly combined cardiovascular and airway malformations and cardiac dysrhythmia.

Where We Can Find Bypass Tract in Ebstein's Anomaly?; a Case of Successful Ablation of Bypass Tract in Ebstein's Anomaly

In patients with Ebstein's anomaly, the localization of accessory pathways may be impeded by abnormal local electrograms recorded along the atrialized right ventricle and by the presence of multiple accessory pathways. We report a case of 50-year-old man diagnosed with Ebstein's anomaly with Wolff-Parkinson-White syndrome who presented with recurrent palpitations. He was referred to our institution for radiofrequency catheter ablation of paroxysmal supraventricular tachycardia. Transthoracic echocardiography revealed the tricuspid valve displaced into the right ventricle, consistent with Ebstein's anomaly. The electrophysiology study showed a right posterolateral accessory pathway. The optimal ablation site was located not in the atrioventricular line of the atrialized ventricular portion, but in the original atrioventricular line.

Accuracy of the Electrocardiogram in Localizing the Accessory Pathway in Patients with Wolff-Parkinson-White Pattern / Acurácia do Eletrocardiograma na Localização da Via Acessória em Pacientes com Padrão de Wolff-Parkinson-White

Abstract Background: There are currently several electrocardiographic algorithms to locate the accessory pathway (AP) in patients with Wolff-Parkinson-White (WPW) syndrome. Objective: To compare the ability of electrocardiographic algorithms in identifying the location of the AP in patients with WPW pattern referred for ablation. Methods: Observational, cross-sectional, retrospective study with 111 patients with WPW syndrome referred for AP ablation. The electrocardiogram (ECG) obtained prior to the ablation was analyzed by an experienced observer who consecutively applied seven algorithms to identify non-invasively the AP. We then compared the location estimated with this assessment with that obtained in the electrophysiological study and calculated the agreement rates. Results: Among the APs, 59 (53.15%) were distributed around the mitral annulus and the remaining 52 (46.85%) were located around the tricuspid annulus. The overall absolute accuracy of the algorithms evaluated varied between 27% and 47%, increasing to between 40% and 76% when we included adjacent locations. The absolute agreement rate by AP location was 2.00-52.20% for septal APs (n = 51), increasing to 5.90-90.20% when considering adjacent locations; 7.70-69.20% for right APs (n = 13), increasing to 42.90-100% when considering adjacent locations; and 21.70-54.50% for left APs (n = 47), increasing to 50-87% when considering adjacent locations. Conclusion: The agreement rates observed for the analyzed scores indicated a low discriminative ability of the ECG in locating the AP in patients with WPW.

Resumo Fundamento: Existem atualmente vários algoritmos eletrocardiográficos para localizar a via acessória (VA) em pacientes com síndrome de Wolff-Parkinson-White (WPW). Objetivo: Comparar a capacidade discriminativa dos algoritmos eletrocardiográficos na localização da VA no padrão de WPW em pacientes encaminhados para ablação. Métodos: Estudo observacional, transversal e retrospectivo, incluindo 111 pacientes com síndrome de WPW encaminhados para ablação da VA. O eletrocardiograma (ECG) prévio à ablação foi analisado por um observador experiente que aplicou consecutivamente sete algoritmos para identificar a VA de forma não invasiva. A localização estimada com esta avaliação foi comparada à obtida no estudo eletrofisiológico e as taxas de acerto foram calculadas. Resultados: Entre as VAs, 59 (53,15%) estavam distribuídas ao redor do anel mitral e as restantes 52 (46,85%) em torno do anel tricúspide. O acerto global absoluto dos algoritmos em estudo variou entre 27% e 47%, aumentando para 40% a 76% quando incluímos localizações adjacentes. O acerto absoluto em função da localização da VA foi o seguinte: para as VAs septais (n = 51) variou entre 2% e 52,20% (5,90% e 90,20% incluindo localizações adjacentes), para as VAs direitas (n = 13) variou entre 7,70% e 69,20% (42,90% e 100%, incluindo localizações adjacentes), para as VAs esquerdas (n = 47) variou entre 21,70% e 54,50% (50% a 87%, incluindo as localizações adjacentes). Conclusões: Os índices de acerto observados para os escores analisados indicaram uma reduzida capacidade discriminativa do ECG na localização da VA em pacientes com WPW.

Spontaneous Transition of Double Tachycardias with Atrial Fusion in a Patient with Wolff-Parkinson-White Syndrome

Among patients with Wolff-Parkinson-White syndrome, atrioventricular reciprocating tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) can coexist in a single patient. Direct transition of both tachycardias is rare; however, it can occur after premature atrial or ventricular activity if the cycle lengths of the two tachycardias are similar. Furthermore, persistent atrial activation by an accessory pathway (AP) located outside of the AV node during ongoing AVNRT is also rare. This article describes a case of uncommon atrial activation by an AP during AVNRT and gradual transition of the two supraventricular tachycardias without any preceding atrial or ventricular activity in a patient with preexcitation syndrome.

A Case of MELAS Syndrome Presenting with Type 1 Diabetes Mellitus / 대한내과학회지

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome presents with various clinical features, including seizures, stroke-like episodes, encephalopathy, myopathy, cardiac involvement, and diabetes. However, due to its clinical heterogeneity, the diagnosis of MELAS syndrome is complex and difficult. The present report describes an 18-year-old male who was diagnosed with MELAS syndrome following the onset of type 1 diabetes. The patient had suffered from ataxia, mental retardation, and recurrent headaches for several years; following hospitalization for loss of consciousness, he was treated for cerebellar atrophy and Wolf-Parkinson-White (WPW) syndrome. Although the patient had no history of lactic acidosis, the recent onset of type 1 diabetes and his medical history of encephalopathy and WPW syndrome suggested MELAS syndrome. The diagnosis of MELAS syndrome was confirmed by molecular genetic testing, which revealed a point mutation (A3243G) in the patient's mitochondrial DNA.

Seguimiento de 134 pacientes pediátricos con patrón de Wolff-Parkinson-White: evolución natural e intervención médica* / Follow-up of 134 Pediatric Patients with Wolff-Parkinson-White Pattern: Natural Outcome and Medical Treatment

Objetivos Evaluar la evolución de una población pediátrica con patrón de preexcitación ventricular, presencia de taquicardia supraventricular, fibrilación auricular, cardiopatías, mortalidad e intervención médica. Material y métodos Estudio descriptivo observacional. Se registraron pacientes con preexcitación ventricular en el electrocardiograma desde 1976 a 2011. Todos tenían ecocardiograma, 101 pacientes Holter (75,3%) y 69 (51,5%) ergometría. En pacientes seleccionados se realizó ablación por radiofrecuencia. Los datos se expresaron como media y desviación estándar. Resultados Se incluyeron en el estudio 134 pacientes, 80 varones (59,7%). Edad al diagnóstico: 2 días a 18 años, media 6,5 ± 5 años. Seguimiento clínico: 1 mes a 20 años, media 3,6 ± 3,9 años. Consultaron por taquicardia supraventricular 35 pacientes (26,1%), por preexcitación ventricular 16 pacientes (11,9%) y por otras causas 83 pacientes (61,9%); 76 pacientes (56,7%) evidenciaron vía izquierda, 3 pacientes doble vía; 16 pacientes (11,9%) presentaron taquicardia supraventricular durante el seguimiento. En total, 51 pacientes (38%) tuvieron taquicardia ortodrómica a los 6,3 ± 5,8 años, 10 pacientes en el período neonatal; 38 pacientes (28,3%) recibieron antiarrítmicos. No se observó fibrilación auricular. Veintiocho pacientes (20,9%) presentaron cardiopatía, 9 con taquicardia supraventricular. No hubo variables vinculadas con taquicardia supraventricular. En 43 pacientes (32,1%) se realizó ablación por radiofrecuencia. Un paciente murió súbitamente. Otro paciente falleció en el posoperatorio de cardiopatía. Conclusiones 1) Más del 60% de los pacientes permanecieron asintomáticos. 2) No se registró fibrilación auricular. 3) La tasa de muerte súbita fue del 0,75%. 4) Los pacientes con taquicardia supraventricular no sometidos a ablación evolucionaron bien. 5) No se asociaron variables con taquicardia supraventricular. 6) Las vías múltiples siempre desarrollaron taquicardia supraventricular.

Objectives The aim of the study was to evaluate the outcome of a pediatric population with ventricular preexcitation pattern, supraventricular tachycardia, atrial fibrillation, cardiomyopathies, mortality and medical treatment. Methods From 1976 to 2011, a descriptive observational study was conducted on patients with ventricular preexcitation in the electrocardiogram. All patients underwent an echocardiogram, 101 (75.3%) Holter monitoring, and 69 (51.5%) an ergometric test. Radiofrequency ablation was performed in selected patients. Data were expressed as mean and standard deviation. Results The study population consisted of 134 patients, 80 (59.7%) of whom were male. Age at diagnosis ranged from 2 days to 18 years, with a mean of 6.5±5 years. Clinical follow-up lasted 1 month to 20 years, with a mean of 3.6±3.9 years. Thirty five patients (26.1%) consulted for supraventricular tachycardia, 16 (11.9%) for ventricular preexcitation, and the remaining 83 patients (61.9%) for other abnormalities. Seventy-six patients (56.7%) evidenced left conduction pathway and 3 patients a double conduction pathway. Sixteen patients (11.9%) presented supraventricular tachycardia during follow-up. Overall, 51 patients (38%) had orthodromic tachycardia at 6.3±5.8 years, 10 patients during the neonatal period. Thirty-eight patients (28.3%) received antiarrhythmic drugs. No atrial fibrillation was observed. Twenty-eight patients (20.9%) presented cardiomyopathy, 9 with supraventricular tachycardia. No association was found between supraventricular tachycardia and another variable. Forty-three patients (32.1%) underwent radiofrequency ablation. A patient suffered sudden death and another patient died during the postoperative period of corrective surgery. Conclusions 1) More than 60% of patients remained asymptomatic. 2) No atrial fibrillation was recorded. 3) Sudden death rate was 0.75%. 4) Patients with supraventricular tachycardia not submitted to ablation had a favorable outcome. 5) Supraventricular fibrillation was not associated with any variable. 6) Multiple conduction pathways always developed supraventricular tachycardia.

Amiodarone and Catheter Ablation as Cardiac Resynchronization Therapy for Children with Dilated Cardiomyopathy and Wolff-Parkinson-White Syndrome

Preexcitation by accessory pathways (APs) is known to cause dyssynchrony of the ventricle, related to ventricular dysfunction. Correction of ventricular dyssynchrony can improve heart failure in cases of dilated cardiomyopathy (DCMP) with preexcitation. Here, we report the first case of a child with DCMP and Wolff-Parkinson-White (WPW) syndrome treated with amiodarone and radiofrequency catheter ablation (RFCA) in Korea. A 7-year-old boy, who suffered from DCMP and WPW syndrome, showed improved left ventricular function and clinical functional class after treatment with amiodarone to eliminate preexcitation. QRS duration and left ventricular ejection fraction (LVEF) were inversely correlated with amiodarone dosage. After confirming the reduction of preexcitation effects in DCMP, successful RFCA of the right anterior AP resulted in LVEF improvement, along with the disappearance of preexcitation. Our findings suggest that ventricular dyssynchrony, caused by preexcitation in DCMP with WPW syndrome, can worsen ventricular function and amiodarone, as well as RFCA, which should be considered as a treatment option, even in young children.