Durham D, Worthley L I G
Department of Critical Care Medicine, Flinders Medical Centre, Adelaide, South Australia.
Crit Care Resusc. 2002 Mar;4(1):35-53.
To review the diagnosis and management of cardiac arrhythmias in a two-part presentation.
Articles and published peer-review abstracts on tachycardias and bradycardias.
Normal cardiac rhythm originates from impulses generated within the sinus node. These impulses are conducted to the atrioventricular node where they are delayed before they are distributed to the ventricular myocardium via the His-Purkinje system. Abnormalities in cardiac rhythm are caused by disorders of impulse generation, conduction or a combination of the two and may be life threatening due to a reduction in cardiac output or myocardial oxygenation. Cardiac arrhythmias are commonly classified as tachycardias (supraventricular or ventricular) or bradycardias. The differentiation between supraventricular and ventricular tachycardias usually requires an assessment of atrial and ventricular rhythms and their relationship to each other. In the critically ill patient the commonest tachycardia is sinus tachycardia and treatment generally consist of management of the underlying disorder. Other supraventricular tachycardias (SVTs) include, atrial flutter, atrial fibrillation and paroxysmal supraventricular tachycardia (PSVT) all of which may require cardioversion, although to maintain sinus rhythm, antiarrhythmic therapy is often needed. Adenosine is useful in management and treatment many SVTs although its use in PSVT with Wolff-Parkinson-White syndrome is hazardous. Multifocal atrial tachycardia is a characteristic supraventricular tachycardia found in the critical ill patient. While it usually responds to intravenous magnesium sulphate, its management also requires removal of various precipitating factors. Ventricular tachycardia (VT) and ventricular fibrillation (VF) require urgent cardioversion and defibrillation respectively. Torsade de pointes should be differentiated from these ventricular arrhythmias as antiarrhythmic therapy may be contraindicated.
Supraventricular and ventricular tachycardias in the critically ill patient often have underlying disorders that precipitate their development (e.g. hypokalaemia, hypomagnesaemia, anti-arrhythmic proarrhythmia, myocardial ischaemia, etc). While antiarrhythmic therapy and cardioversion or defibrillation may be required to achieve sinus rhythm, correction of the associated abnormalities is also required.
分两部分介绍心律失常的诊断与处理。
关于心动过速和心动过缓的文章及发表的同行评审摘要。
正常心脏节律起源于窦房结产生的冲动。这些冲动传导至房室结，在此处延迟后通过希氏-浦肯野系统分布到心室肌。心律失常由冲动产生、传导障碍或两者共同作用引起，可能因心输出量减少或心肌氧合作用降低而危及生命。心律失常通常分为心动过速（室上性或室性）或心动过缓。室上性和室性心动过速的鉴别通常需要评估心房和心室节律及其相互关系。在危重症患者中，最常见的心动过速是窦性心动过速，治疗通常包括处理潜在疾病。其他室上性心动过速（SVT）包括心房扑动、心房颤动和阵发性室上性心动过速（PSVT），所有这些都可能需要心脏复律，不过为维持窦性心律，通常需要抗心律失常治疗。腺苷对许多SVT的处理和治疗有用，尽管其在伴有预激综合征的PSVT中使用有风险。多源性房性心动过速是危重症患者中一种特征性的室上性心动过速。虽然它通常对静脉注射硫酸镁有反应，但其处理还需要消除各种诱发因素。室性心动过速（VT）和心室颤动（VF）分别需要紧急心脏复律和除颤。尖端扭转型室速应与这些室性心律失常相鉴别，因为抗心律失常治疗可能禁忌。
危重症患者的室上性和室性心动过速通常有促使其发生的潜在疾病（如低钾血症、低镁血症、抗心律失常药物致心律失常作用、心肌缺血等）。虽然可能需要抗心律失常治疗及心脏复律或除颤来实现窦性心律，但也需要纠正相关异常情况。
