Asymptomatic Wolff-Parkinson-White Syndrome: An Ounce of Prevention Is Worth the Risk of Cure.

PURPOSE OF REVIEW: With increased electrocardiogram screening, asymptomatic preexcitation has become more prevalent. Historically, the asymptomatic-symptomatic dichotomy has directed management. This approach warrants scrutiny, as asymptomatic Wolff-Parkinson-White (WPW) syndrome is not without risk. Children may be unreliable symptom reporters, have atypical arrhythmia symptoms, yet have years to become symptomatic. RECENT FINDINGS: In a large WPW study, symptomatic patients were more likely to undergo ablation than asymptomatic patients, yet, except for symptoms, there were no differences in clinical or electrophysiology study (EPS) characteristics. Present data confirm real risk in asymptomatic WPW-sudden death can be the first symptom. Although malignant arrhythmias correlate better with EPS risk stratification than with symptoms, EPS data are imperfect predictors. Unlike adults with WPW, children have yet to prove survivorship. Asymptomatic children must be treated differently than adults. Sudden death risk is low but front-loaded in the young. An aggressive approach to asymptomatic WPW is warranted in this era of highly successful, low-risk catheter ablations.

Reentry Tachycardia in Children: Adenosine Can Make It Worse.

OBJECTIVES: We report on a rare but severe complication of adenosine use in a child with reentry tachycardia. METHODS AND RESULTS: Treatment with adenosine, which is the standard medical therapy of atrioventricular reentry tachycardia, led to the development of an irregular wide complex tachycardia, caused by rapid ventricular response to atrial fibrillation. The girl was finally stabilized with electrical cardioversion. We analyze the pathomechanism and discuss possible treatment options. CONCLUSIONS: Atrial fibrillation, as well as its conduction to the ventricles, can be caused by adenosine. Rapid ventricular response in children with Wolff-Parkinson-White syndrome is more frequent than previously believed. A patient history of atrial fibrillation is a contraindication for cardioversion with adenosine and needs to be assessed in children with reentry tachycardia. High-risk patients may potentially profit from prophylactic comedication with antiarrhythmic agents, such as flecainide, ibutilide, or vernakalant, before adenosine administration.

Papillary Muscle Rupture in an Adolescent with No Coronary Lesions.

A 21-year-old man with Wolff-Parkinson-White syndrome presented to the authors' hospital with ventricular fibrillation. Coronary angiography failed to demonstrate coronary stenosis, but temporary mechanical circulatory support resolved the ventricular fibrillation and the patient was extubated eight days later. On the next day, however, he had to be re-intubated with symptoms of congestive heart failure. Echocardiography revealed new severe mitral regurgitation and a mobile mass, while emergency surgery revealed a posteromedial papillary muscle rupture (PMR). The mitral regurgitation was repaired with ruptured papillary muscle relocation, artificial chordae implantation, and ring annuloplasty. Postoperative examinations suggested that an arrhythmia-induced coronary circulation hypoperfusion and septic embolization had caused the PMR.

Genome editing with CRISPR/Cas9 in postnatal mice corrects PRKAG2 cardiac syndrome.

PRKAG2 cardiac syndrome is an autosomal dominant inherited disease resulted from mutations in the PRKAG2 gene that encodes γ2 regulatory subunit of AMP-activated protein kinase. Affected patients usually develop ventricular tachyarrhythmia and experience progressive heart failure that is refractory to medical treatment and requires cardiac transplantation. In this study, we identify a H530R mutation in PRKAG2 from patients with familial Wolff-Parkinson-White syndrome. By generating H530R PRKAG2 transgenic and knock-in mice, we show that both models recapitulate human symptoms including cardiac hypertrophy and glycogen storage, confirming that the H530R mutation is causally related to PRKAG2 cardiac syndrome. We further combine adeno-associated virus-9 (AAV9) and the CRISPR/Cas9 gene-editing system to disrupt the mutant PRKAG2 allele encoding H530R while leaving the wild-type allele intact. A single systemic injection of AAV9-Cas9/sgRNA at postnatal day 4 or day 42 substantially restores the morphology and function of the heart in H530R PRKAG2 transgenic and knock-in mice. Together, our work suggests that in vivo CRISPR/Cas9 genome editing is an effective tool in the treatment of PRKAG2 cardiac syndrome and other dominant inherited cardiac diseases by selectively disrupting disease-causing mutations.

Risk factors for maternal and fetal outcome in pregnancy complicated by Ebstein anomaly.

OBJECTIVE: The goal of the study was to examine risks in pregnancy in patients with Ebstein anomaly. STUDY DESIGN: Data were examined retrospectively for 13 patients (27 pregnancies, 21 live births) with Ebstein anomaly during pregnancy who were treated at our institution from 1985 to 2011. The associated anomalies in these patients were atrial septal defect (ASD) (n = 4) and the Wolff-Parkinson-White syndrome (n = 6). RESULTS: Before pregnancy, 2 patients underwent ASD closure and 1 received tricuspid valve replacement (TVR). In all patients, the cardiothoracic ratio increased from 55.1 at conception to 57.0 during pregnancy and 58.0 postpartum (P < .05). Cesarean sections were performed in 3 cases: 1 with ventricular tachycardia and orthopnea (New York Heart Association [NYHA] III) preterm; at full term, and the third in a patient with a mechanical tricuspid valve who developed maternal cerebellum hemorrhage at 27 weeks. The baby died of prematurity in the third case. In all other cases (20 of 21), neonatal prognoses were good without congenital heart diseases. There were 6 spontaneous abortions. Recurrent paroxysmal supraventricular tachycardia occurred during pregnancy in 2 cases and was treated with adenosine triphosphate or verapamil. In 17 pregnancies, NYHA remained in class I and all had full-term vaginal delivery. CONCLUSION: Maternal and fetal outcomes are good in patients with Ebstein anomaly and NYHA class I. However, pregnancy in Ebstein anomaly can be complicated with tachyarrhythmia or cardiac failure. In post-TVR cases, meticulous care is required for these complications during pregnancy and delivery.

Malignant arrhythmia as the first manifestation of Wolff-Parkinson-White syndrome: a case with minimal preexcitation on electrocardiography.

Wolff-Parkinson-White (WPW) syndrome is defined as the presence of an accessory atrioventricular pathway which is manifested as delta waves and short PR interval on electrocardiography (ECG). However, some WPW cases do not have typical findings on ECG and may remain undiagnosed unless palpitations occur. Sudden cardiac death may be the first manifestation of WPW and develops mostly secondary to degeneration of atrial fibrillation into ventricular fibrillation. In this report, we present a case of undiagnosed WPW with minimal preexcitation on ECG and who suffered an episode of malignant arrhythmia as the first manifestation of the disease.

Acute supraventricular tachycardia in children.

This article describes the management in emergency departments of supraventricular tachycardia (SVT) in children. Of all forms of symptomatic arrhythmia in infants, children and adolescents, SVT is the most common. Its clinical presentation varies with the child's age, and it can be difficult to diagnose in infants and young children. It is important that the nurses in the emergency department consider a diagnosis of SVT in young children with histories of poor feeding, lethargy, irritability, excessive sweating or pallor (Zeigler 1994) and in older children with histories of palpitations, dizziness, chest pain, syncope or shortness of breath (Uzun 2010). If SVT is suspected, a 12-lead electrocardiogram should be recorded. Vagal manoeuvre may be successful but in some cases intravenous adenosine is necessary. Children with Wolff-Parkinson-White syndrome are at risk of sudden cardiac death associated with SVT, and should not be treated with calcium channel blockers or digoxin.

Contributions of the Instituto Nacional de Cardiología in the diagnosis and treatment of the Wolff-Parkinson-White syndrome / Contribuciones del Instituto Nacional de Cardiología al diagnóstico y tratamiento del síndrome de Wolff-Parkinson-White

Since the first description of the disease now known as Wolff-Parkinson-White syndrome, much knowledge has been gained through several experimental and clinical studies all over the world. The Instituto Nacional de Cardiología Ignacio Chávez in Mexco City has not been the exception. In this report, we describe the clinical, electrocardiographic and electrophysiologic contributions of past and present researchers at the Institute, as well as the experience in the diagnosis and treatment of the W-P-W syndrome at this Instituto Nacional de Cardiología Ignacio Chávez.

Desde la primera descripción de la enfermedad que ahora conocemos como Wolff-Parkinson-White, se ha acumulado una fuente importante de conocimientos a través de múltiples estudios clínicos y experimentales realizados en todo el mundo. El Instituto Nacional de Cardiología Ignacio Chávez no ha sido la excepción, en esta revisión se describen las contribuciones de los investigadores de dicho Instituto, tanto en los aspectos clínicos, electrocardiográficos y electrofisiológicos. Asimismo se presenta la experiencia del Instituto en el diagnóstico y tratamiento de esta entidad.

O dilema da taquicardia de QRS largo

Trata-se de um caso de taquicardia de QRS largo que é confundida com taquicardia ventricular. O ECG, após a reversão ao ritmo sinusal, mostra sinais de pré-excitação. A comparação permite concluir que o paciente apresenta síndrome de Wolff-Parkinson-White em que a TSV paroxística tem reentrada antidrômica.A importância clínica do diagnóstico correto da taquicardia é que TV e TSV têm tratamentos distintos durante a crise. Além do mais, o portador da síndrome de Wolff-Parkinson-White pode ser encaminhado para terapêutica curativa por ablação da via acessória por radiofrequência através de cateterismo cardíaco.

Ablación transcatéter con radiofrecuencia y tratamiento definitivo del síndrome de Wolff-Parkinson-White: Reporte de una experiencia inicial en el Perú / Ablation transcateter with radio frequency and definitive treatment of Wolff-Parkinson-White's syndrome: Report of an initial experience in the Peru

Antecedentes: El síndrome de Wolff-Parkinson-White (WPW) fue descrito originalmente en 1930 y tuvo un tratamiento farmacológico inicial limitado. Con el advenimeinto de nuevas drogas antiarrítmicas muchos pacientes (pts) se hicieron refractarios a las mismas, por lo que nuevas estrategias de manejo resultaron necesarias. La ablación quirúrgica pudo curar de manera efectiva a estos pts. sin embargo, requería de cirugía cardiaca a tórax abierto con la consiguiente morbimortalidad inherente a dicho procedimiento. La ablación por catéter con radiofrecuencia es una técnica mas reciente que ha demostrado ser útil y efectiva en el tratamiento curativo de este síndrome, sin embargo, poco es conocido en nuestro medio acerca de esta estrategia de manejo en este particular grupo de pacientes. Objetivo: Presentar una experiencia inicial en nuestros medio usando esta técnica, así como mostrar su efectividad y seguridad en el tratamiento definitivo de estos pts. Material y métodos: Ochenta pts. con diagnóstico de síndrome de WPW (Onda delta y crisis de taquiarritmias), en edades comprendidas entre 06 y 65 años, correspondiendo 55 al sexo masculino, experimentaron ablación transcatéter usando radiofrecuencia debido a refractoriedad a medicación, efectos colaterales o no deseo de tomar las mismas de manera prolongada. El procedimiento fue realizado por punción vascular con anestesia local y la energía fue aplicada a través de la punta del catéter de ablación a nivel del endocardio de los anillos mitral y tricuspídeo. Los pts. fueron dados de alta al día siguiente sin medicación antiarrítmica y seguidos a largo plazo para la evaluación de recurrencia. Resultados: Un total de 84 vías accesorias fueron identificadas, correspondiendo 59 a nivel del anillo mitral (44 lateral, 06 anterolateral, 05 posterolateral, 04 posterior), 25 en el anillo tricuspídeo (posteroseptal 15, posterior 01, lateral 02, anterior 02, medioseptal 03) y 03 en posición subepicárdica. El éxito inicial fue...

Supraventricular tachycardia in children.

Several different mechanisms are responsible for paroxysmal supraventricular tachycardia in children. Different forms of tachycardia occur at different age. Atrio-ventricular reentry tachycardia results from the presence of congenital atrio-ventricular bypass tracts and is frequently encountered at all ages. Infants may present with ectopic atrial tachycardia or atrial flutter. Atrio-ventricular node reentry tachycardia becomes more frequent in adolescence. Atrial scarring resulting from open heart surgery predisposes to complex intra-atrial reentry. Certain forms of congenital and acquired heart disease are associated with specific types of arrhythmia. Many children with paroxysmal supraventricular tachycardia do not require any therapy. The decision to proceed with treatment should be based on the frequency and severity of symptoms and on the effect of arrhythmia on the quality of life. Infants require medical treatment because of the difficulty to recognize symptoms of tachycardia and a risk of heart failure. Patients with Wolff-Parkinson-White syndrome as well as those with significant heart disease are at risk of sudden death. Syncope in children with paroxysmal tachycardia may indicate a severe fall in cardiac output from extremely rapid heart rate. Patients with potentially life-threatening arrhythmia should not participate in competitive physical activities. Treatment options have undergone significant evolution over the past decade. Indications for the use of specific antiarrhythmic medications have been refined. Contemporary catheter ablation procedures employ different forms of energy allowing for safe and effective procedures. Catheter ablation is the treatment of choice for symptomatic paroxysmal tachycardia in school children and in some infants who failed medical treatment. Surgery is the preferred treatment in few selected cases. The goal of this review is to present the state of the art approach to the diagnosis and management of paroxysmal supraventricular tachycardia in infants, children and adolescents.

Adenosine monophosphate-activated protein kinase disease mimicks hypertrophic cardiomyopathy and Wolff-Parkinson-White syndrome: natural history.

OBJECTIVES: The aim of this study was to investigate the clinical expression of adenosine monophosphate-activated protein kinase (AMPK) gene mutations (PRKAG2) in adenosine monophosphate (AMP) kinase disease based on 12 years follow-up of known mutation carriers and to define the prevalence of PRKAG2 mutations in hypertrophic cardiomyopathy (HCM). BACKGROUND: Adenosine monophosphate-activated protein kinase gene mutations cause HCM with Wolff-Parkinson-White syndrome and conduction disease. METHODS: Clinical evaluation of 44 patients with known AMP kinase disease was analyzed. Mutation analysis of PRKAG2 was performed by fluorescent single-strand confirmation polymorphism analysis and direct sequencing of abnormal conformers in 200 patients with HCM. RESULTS: Only one additional mutation was identified. The mean age at clinical diagnosis in the 45 gene carriers was 24 years (median 20 years, range 9 to 55 years). Symptoms of palpitation, dypspnea, chest pain, or syncope were present in 31 (69%) gene carriers; 7 (15%) complained of myalgia and had clinical evidence of proximal myopathy. Skeletal muscle biopsy showed excess mitochondria and ragged red fibers with minimal glycogen accumulation. Disease penetrance defined by typical electrocardiogram abnormalities was 100% by age 18 years. Thirty-two of 41 adults (78%) had left ventricular hypertrophy (LVH) on echocardiography, and progressive LVH was documented during follow-up. Survival was 91% at a mean follow-up of 12.2 years. Progressive conduction disease required pacemaker implantation in 17 of 45 (38%) at a mean age of 38 years. CONCLUSIONS: The AMP kinase disease is uncommon in HCM and is characterized by progressive conduction disease and cardiac hypertrophy and includes extracardiac manifestations such as a skeletal myopathy, consistent with a systemic metabolic storage disease. Defects in adenosine triphosphate utilization or in specific cellular substrates, rather than mere passive deposition of amylopectin, may account for these clinical features.