Lowenstein S R, Halperin B D, Reiter M J
Division of Emergency Medicine, Colorado Emergency Medicine Research Center, University of Colorado Health Sciences Center, Denver 80262, USA.
J Emerg Med. 1996 Jan-Feb;14(1):39-51. doi: 10.1016/0736-4679(95)02061-6.
Paroxysmal supraventricular tachycardia (PSVT) is a distinct clinical syndrome. Most patients present with the abrupt onset of palpitations, dizziness, dyspnea, or chest pain. The electrocardiogram (ECG) demonstrates a fast heart rate (150-250 beats per min), a regular rhythm, and most often, a narrow QRS complex. The P wave is usually hidden within the QRS complex. PSVT is caused by reentry, and the tachycardias are classified, electrophysiologically, according to the anatomic location of the reentry circuit. Atrioventricular nodal reentry is the most common form of PSVT. In A-V nodal reentry, there are two conducting pathways (alpha and beta) that have different conduction times and refractory periods; both pathways are confined to the A-V nodal and perinodal atrial tissue. The other common form of PSVT, termed atrioventricular reciprocating tachycardia, depends on an anatomically distinct, or "accessory," pathway that may conduct impulses between the atria and the ventricles, while bypassing the AV node. The two forms of PSVT may be distinguished in many cases by examining the 12-lead electrocardiogram. In the majority of cases of A-V nodal reentry, the atria and ventricles are depolarized simultaneously, and the P waves are hidden in the QRS complex. If the reentry circuit includes an accessory pathway, the P wave always follows the QRS, and usually the R-P interval exceeds 70 msec. Several principles should guide the management of PSVT: (a) Unstable patients require emergent electrical cardioversion; (b) A 12-lead ECG should be obtained immediately to confirm that the tachycardia has a narrow complex (ventricular tachycardia may masquerade as PSVT if only a single lead is examined); (c) Vagal maneuvers may be attempted (the Valsalva maneuver is safer and more efficacious, especially in the elderly); and (4) In most patients, adenosine is the first-line agent to treat PSVT. Contraindications to adenosine and drug interactions are noted in this article. In addition, the use of adenosine in wide complex tachycardias and the indications for admission and referral for electrophysiologic evaluation are discussed.
阵发性室上性心动过速（PSVT）是一种独特的临床综合征。大多数患者表现为心悸、头晕、呼吸困难或胸痛突然发作。心电图（ECG）显示心率加快（每分钟150 - 250次）、节律规则，且大多数情况下QRS波群狭窄。P波通常隐藏在QRS波群内。PSVT由折返引起，根据折返环路的解剖位置，从电生理角度对心动过速进行分类。房室结折返是PSVT最常见的形式。在房室结折返中，有两条传导路径（α和β），其传导时间和不应期不同；两条路径均局限于房室结和结周心房组织。PSVT的另一种常见形式称为房室折返性心动过速，它依赖于一条解剖学上不同的或“附加”路径，该路径可在心房和心室之间传导冲动，同时绕过房室结。在许多情况下，通过检查12导联心电图可区分这两种形式的PSVT。在大多数房室结折返病例中，心房和心室同时去极化，P波隐藏在QRS波群中。如果折返环路包括一条附加路径，P波总是跟随QRS波，且通常R - P间期超过70毫秒。有几条原则应指导PSVT的治疗：（a）不稳定患者需要紧急电复律；（b）应立即获取12导联心电图以确认心动过速的QRS波群狭窄（如果仅检查单导联，室性心动过速可能伪装成PSVT）；（c）可尝试迷走神经手法（瓦尔萨尔瓦动作更安全、更有效，尤其在老年人中）；以及（4）在大多数患者中，腺苷是治疗PSVT的一线药物。本文提及了腺苷的禁忌证和药物相互作用。此外，还讨论了腺苷在宽QRS波群心动过速中的应用以及电生理评估的入院和转诊指征。
