Article Sections

Introduction

Supraventricular tachycardia (SVT) is a broad classification term for tachycardias that originate proximal to the bundle branches and Purkinje fibers in the cardiac conduction system ( Figure 1); these arrhythmias may originate within the sinoatrial node, the atria, the atrioventricular (AV) node, or the His bundle.  In SVT, the ventricles are usually depolarized normally via the His-Purkinje system, typically resulting in narrow QRS complexes (ie, <120 msec) on ECG.

Pathophysiology and types of SVT

The classification of SVT is somewhat confusing and varies in different resources.  In general, tachyarrhythmias reflect a disorder of either impulse generation (eg, ectopic activity) or impulse propagation (eg, abnormal conduction circuit).  Using this framework, this article provides a conceptual approach based on the typical point of origin ( Figure 2

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