Catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disorder that causes syncopal episodes related with stress or emotion and even sudden cardiac deaths. Signs and symptoms usually begin in childhood. A suspicion of CPVT should be kept in mind when a child or an adolescent suddenly loses consciousness, particularly if this happens upon physical exercise or sudden mental stress. During the past decade, the knowledge of CPVT genetics and physiology has increased. Exercise testing is essential when suspecting arrhythmogenic origin of syncope, and in the case of CPVT, it may be even more sensitive than Holter monitoring. Beta-antiadrenergic medication can substantially decrease the mortality associated with CPVT. Asymptomatic patients with known CPVT gene defects should also be treated because sudden cardiac death may be the first manifestation of the disease. An implantable cardioverter-defibrillator may also be required in the most severe CPVT cases. In this review, we summarise the current knowledge on the clinical characteristics, diagnostic, genetic and prognostic features of CPVT in children. In all, 133 publications covering 60 years were checked, and those written in English and containing ten or more, mainly paediatric CPVT cases, were included. In addition, a CPVT family with three members and delayed diagnoses until late childhood and adulthood is presented.     

Deadly proposal: a case of catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare adrenergically mediated arrhythmogenic disorder classically induced by exercise or emotional stress and found in structurally normal hearts. It is an important cause of cardiac syncope and sudden death in childhood. Catecholaminergic polymorphic ventricular tachycardia is a genetic cardiac channelopathy with known mutations involving genes affecting intracellular calcium regulation. We present a case of a 14-year-old boy who had cardiopulmonary arrest after an emotionally induced episode of CPVT while attempting to invite a girl to the school dance. Review of his presenting cardiac rhythm, induction of concerning ventricular arrhythmias during an exercise stress test, and genetic testing confirmed the diagnosis of CPVT. He recovered fully and was treated with β-blocker therapy and placement of an implantable cardioverter-defibrillator. In this report, we discuss this rare but important entity, including its molecular foundation, clinical presentation, basics of diagnosis, therapeutic options, and implications of genetic testing for family members. We also compare CPVT to other notable cardiomyopathic and channelopathic causes of sudden death in youth including hypertrophic cardiomyopathy, arrhythmogenic right ventricular dysplasia, long QT syndrome, short QT syndrome, and Brugada syndrome.     

Inherited catecholaminergic polymorphic ventricular tachycardia due to RYR2 mutation

We report the case of an 11‐year‐old boy who was diagnosed with catecholaminergic polymorphic ventricular tachycardia (CPVT). The patient had a medical history of three episodes of syncope. The last episode was cardiac arrest while swimming. After resuscitation using automated external defibrillator, he was placed under cerebral hypothermia, examined for long QT syndrome, and underwent insertion of implantable cardioverter defibrillator. He was subsequently discharged from hospital without any adverse sequelae. The patient was diagnosed with CPVT after detection of ryanodine receptor 2 mutation. His father also carried the same mutation, although he did not have any symptoms nor did he have a history of syncope. We propose that CPVT should be included in the differential diagnosis in children with recurrent episodes of syncope.     

儿茶酚胺敏感性多形性室性心动过速患者的长期预后及室性心律失常的预测

目的：目前对儿茶酚胺敏感性多形性室性心动过速（CPVT）的临床特征的认识相对不足,并缺少完善的评估疗效、预测室性心律失常的方法,本研究对CPVT的治疗及预后进行长期随访,评估室性心律失常的预测指标。方法：6例CPVT患者给予β受体阻滞剂,部分患者给予普罗帕酮,1例患者给予导管消融肾动脉去交感神经术治疗。观察心电图、心律失常特点及长期随访预后。结果：6例患者经治疗后1例未再发生晕厥,3例因停β受体阻滞剂一次而发生晕厥,1例因停服β受体阻滞剂猝死,1例仍反复晕厥后猝死。所有患者于胸导联出现ST段抬高、T波双峰或倒置,4例患者出现T电交替,部分患者可见明显的U波,β受体阻滞剂治疗后这些心电异常消失或减轻。所有患者室性心动过速发作前均有窦性心动过速及频发室性早搏。结论：T波双峰或倒置、T波电交替、U波增高可能是CPVT的心电图特点,观察这些心电异常及有无窦性心动过速、频发室性早搏有助于评估β受体阻滞剂的疗效及预测致死性室性心律失常。β受体阻滞剂的依从性是预测预后的强烈指标。     

Catecholaminergic polymorphic ventricular tachycardia in a child: a case report

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare arrythmogenic disease characterized by exercise--or stress--induced ventricular tachyarrythmias, syncope, or sudden death, usually in the pediatric age group. Familial occurrence has been noted in about 30% of cases. Inheritance may be autosomal dominant or recessive, usually with high penetrance. The causative genes have been mapped to chromosome 1. Mutations of the cardiac ryanodine receptor gene (RyR2) have been identified in autosomal dominant pedigrees, while calsequestrin gene (CASQ2) mutations are seen in recessive cases. CONCLUSION: Due to its potential lethal outcome, exclusion or confirmation of catecholaminergic polymorphic ventricular tachycardia in children with physical and emotional syncope is mandatory. We report a case of catecholaminergic polymorphic ventricular tachycardia in a three-year-old child only diagnosed by genetic mapping.     

Catecholaminergic polymorphic ventricular tachycardia: successful emergency treatment with intravenous propranolol

Catecholaminergic polymorphic ventricular tachycardia (VT) is a rare arrhythmogenic disorder, which may cause sudden death and whose relationships with mutations in cardiac ryanodine receptor gene have been recently established. The present article reports a catecholaminergic polymorphic VT case of a 9-year-old girl, without any previous history of syncope, who has been found unconscious while playing and referred comatose to pediatric intensive care unit. The electrocardiogram pattern showed runs of bidirectional and polymorphic VT degenerating into ventricular fibrillation, without QT interval abnormalities. Various attempts of cardioversion, lidocaine, and magnesium sulfate intravenous infusions were only partially effective. Owing to catecholaminergic polymorphic VT highly suggesting electrocardiogram pattern, intravenous propranolol was administered, achieving immediate VT interruption. Long-term nadolol therapy effectively prevented further arrhythmias, with no relapses up to 10 months later; a good neurologic recovery was also obtained. Genetic evaluation revealed in this patient-but not in relatives-a mutation in ryanodine receptor gene on chromosome 1.     

Catecholaminergic polymorphic ventricular tachycardia in a child: an often unrecognized diagnosis]

Catecholaminergic polymorphic ventricular tachycardia is important to be diagnosed as an underlying disease in children with syncope and normal heart, because of its poor prognosis. CASE REPORT: A 3-year-old boy was referred for stress and emotion induced syncope. Primary ventricular arrhythmia, consisting of salvos of bidirectional ventricular tachycardia, was reproducibly induced by physical exertion. The syncopal events and severe arrhythmia disappeared with beta-blocking therapy. CONCLUSION: Despite its rare occurrence, catecholaminergic polymorphic ventricular tachycardia is an important cause of stress and emotion induced syncope and sudden death in children.     

Novel ryanodine receptor 2 mutation associated with a severe phenotype of catecholaminergic polymorphic ventricular tachycardia

An adolescent girl with a history of anxiety associated seizure-like episodes was ultimately diagnosed with catecholaminergic polymorphic ventricular tachycardia. She tested positive for a novel mutation of the ryanodine receptor. The report underscores how genetic arrhythmia syndromes may be mistaken for neurologic disorders.     

Iatrogenic ventricular tachycardia

Cardiac arrhythmias may complicate the clinical course in infants and children following cardiac surgery. Here, we report on a 6-week-old neonate who developed life-threatening ventricular tachycardia with cardio-circulatory compromise after the removal of a substernal catheter that surrounded the heart. The treating physician should be prepared for device-related ventricular tachycardia when temporary devices are removed, and adequate treatment must be initiated immediately.     

普罗帕酮联合普萘洛尔治疗儿茶酚胺敏感性多形性室性心动过速1 例报告并文献复习

目的探讨儿茶酚胺敏感性多形性室性心动过速(CPVT)的诊断和治疗。方法回顾分析1例CPVT患儿的临床资料,并复习相关文献。结果男性患儿,5岁2个月,间歇性心前区不适8月余,运动时晕厥发作2次。24小时动态心电图以及运动试验,窦性心率110 次/min即出现室性心律失常,随着心率增加室性心律失常频数增加,可见双向及多形性室速。基因检测示RYR2基因变异c.6886GA(p.E2296K)。予大剂量普萘洛尔治疗,症状未缓解且心电检查无明显改善,后加用普罗帕酮获得改善。随访1年,患儿未再有运动胸闷不适,动态心电图及运动试验显示无室性心律失常。结论 CPVT以运动或情绪激动诱发双向型和/或多形性室性心动过速为主要临床特征,晕厥、猝死为主要临床表现,普罗帕酮可能可以替代或联合用药治疗CPVT。     

Exercise-induced ventricular tachycardia in children

Two children with exercise-induced tachycardia, one with idiopathic long-QT syndrome, are presented. The patients were evaluated by exercise testing and electrophysiologic study. From the onset of treatment with the beta-blocking agent, pindolol, the patients have been symptom-free. These findings emphasize that children with syncope must be evaluated by ECG, exercise testing, 24-h Holter-monitoring, and finally, electrophysiological study.     

Incessant ventricular tachycardia in infancy

Two infants with incessant tachycardia uncontrolled by multiple drug treatment were thought initially to have supraventricular tachycardia. Careful examination of the 12-lead electrocardiogram suggested ventricular tachycardia, which was confirmed by electrophysiological studies. Intra-operative mapping showed that the arrhythmia arose from the posterior left ventricular free wall in one infant and at the left ventricular apex in the other. Cryoablation of these foci led to cessation of ventricular tachycardia. Myocardial biopsy showed hamartomatous involvement in the first infant and normal tissue in the other. In the first infant the incessant arrhythmia was cured but in the other it recurred 4 months later. The origin of the recurrent tachycardia was adjacent to the previously cryoablated arrhythmogenic area. This area was also cryoablated, leading to disappearance of the ventricular tachycardia. Both patients are free of arrhythmia 10 months and 3 months after their surgery. Surgically ablatable lesions are common in infants with incessant ventricular tachycardia. Early diagnosis and prompt surgical treatment usually can effect 'cure' of this potentially fatal problem in childhood.     

Adenosine-sensitive right ventricular tachycardia in children

Right ventricular outflow tachycardia is a distinct subgroup of idiopathic ventricular tachycardia (VT) with characteristic clinical and electrophysiologic properties. This study was planned to evaluate the effects of adenosine on idiopathic right ventricular tachycardia in children, and to assess the long-term efficacy of verapamil treatment. Diagnostic tests including electrocardiogram, chest roentgenogram, echocardiogram, exercise stress test and 24-hour ambulatory electrocardiographic monitoring were performed in each patient. Adenosine was administered in increasing amounts until an effective dose or a maximal dose of 300 micrograms/kg was reached. In adenosine-sensitive patients verapamil was given orally (3-10 mg/kg/day) for long-term suppression of arrhythmia. Seven patients with a mean age of 10.2 +/- 4.7 years were enrolled in the study. There were five male and two female patients. Six patients had VT, and one patient had frequent ventricular ectopic bests. Arrhythmia originated from the right ventricle in all patients. Adenosine was effective in terminating the arrhythmia in all patients, with a mean effective dose of 183 +/- 75 micrograms/kg. Favorable long-term results (mean follow-up period 17 +/- 8 months) were obtained with verapamil treatment at an average dose of 6.3 +/- 2.2 mg/kg. In conclusion, adenosine can be used effectively for termination of VT originating from the right ventricular outflow tract in children. In these patients verapamil may be considered as the drug of choice for long-term therapy.