Ashraf Muddasir, Collier Sara A.
Trinity Medical Center, Rock Island IL
Oklahoma Dept of Corrections
Junctional ectopic tachycardia (JET) is a rare but clinically significant arrhythmia typically occurring in infants and children. This arrhythmia originates in the atrioventricular (AV) node or AV junction, including the bundle of His (BH), and is classified into 2 distinct forms: congenital junctional ectopic tachycardia (CJET) and postoperative junctional ectopic tachycardia (POJET). JET is characterized by abnormal automaticity rather than reentrant mechanisms, a distinction that has important implications for diagnosis and treatment. CJET may present without prior cardiac surgery and can be evident even at birth. This type is associated with substantial morbidity and mortality—reaching as high as 35% in untreated or refractory cases—owing to its often aggressive course and resistance to standard medical therapies. POJET, in contrast, typically develops within the first 72 hours following surgical repair of congenital heart defects. POJET has been attributed to ischemia, mechanical stretching, and direct trauma to the AV conduction system during surgical intervention. Unlike AV nodal reentrant tachycardia (AVNRT) or AV reentrant tachycardia (AVRT), POJET is not driven by a reentry circuit. Clinically, it may present with either a regular or irregular rhythm, with findings such as 1:1 retrograde atrial conduction or AV dissociation with variable ventricular responses. JET often leads to significant hemodynamic compromise due to its rapid ventricular rates, loss of AV synchrony, and resulting reduction in cardiac output. If not promptly recognized and appropriately managed, JET can rapidly progress to low cardiac output syndrome or cardiovascular collapse. Treatment remains challenging, often requiring a combination of supportive measures, antiarrhythmic medications, and sometimes advanced interventions such as temporary pacing or extracorporeal support. Given its complex pathophysiology, variable clinical presentations, and the evolving landscape of therapeutic options, this review aims to provide a comprehensive overview of junctional ectopic tachycardia. This activity discusses its epidemiology, pathophysiology, clinical features, diagnostic approach, and management strategies, with particular attention to both congenital and postoperative forms, and highlights recent advances that may improve outcomes in this vulnerable population.
交界性异位性心动过速（JET）是一种罕见但具有临床意义的心律失常，通常发生于婴幼儿和儿童。这种心律失常起源于房室（AV）结或房室交界区，包括希氏束（BH），并分为两种不同形式：先天性交界性异位性心动过速（CJET）和术后交界性异位性心动过速（POJET）。JET的特征是异常自律性而非折返机制，这一区别对诊断和治疗具有重要意义。CJET可能在没有先前心脏手术的情况下出现，甚至在出生时就很明显。由于其病程通常较为凶险且对标准药物治疗耐药，这种类型与相当高的发病率和死亡率相关——在未经治疗或难治性病例中高达35%。相比之下，POJET通常在先天性心脏缺陷手术修复后的头72小时内发生。POJET被认为是由于手术干预期间对房室传导系统的缺血、机械拉伸和直接创伤所致。与房室结折返性心动过速（AVNRT）或房室折返性心动过速（AVRT）不同，POJET不是由折返环路驱动的。临床上，它可能表现为规则或不规则节律，伴有诸如1:1逆行心房传导或房室分离伴心室反应多变等表现。由于其快速的心室率、房室同步性丧失以及心输出量降低，JET常导致显著的血流动力学损害。如果不能及时识别并妥善处理，JET可迅速进展为低心输出量综合征或心血管崩溃。治疗仍然具有挑战性，通常需要综合支持措施、抗心律失常药物，有时还需要诸如临时起搏或体外支持等高级干预措施。鉴于其复杂的病理生理学、多变的临床表现以及不断发展的治疗选择格局，本综述旨在全面概述交界性异位性心动过速。本活动讨论其流行病学、病理生理学、临床特征、诊断方法和管理策略，特别关注先天性和术后形式，并强调可能改善这一脆弱人群预后的最新进展。
