Supraventricular tachycardia

Supraventricular tachycardia (SVT) is rarely life-threatening, but can cause troublesome symptoms.

It occurs more frequently in women than men; most commonly in 30-50 year olds.

Atrio-ventricular nodal re-entrant tachycardia (AVNRT) and atrio-ventricular re-entrant tachycardia (AVRT) are the most common forms of SVT.

Appropriate ECG documentation should be sought to aid diagnosis of SVT.

Part 1: Aetiology and epidemiology

Supraventricular tachycardia (SVT) describes a regular narrow complex tachycardia (NCT) (usually > 100bpm) with a QRS duration of 120ms or less.¹ SVT is a relatively common arrhythmia affecting approximately 2-3 per cent of the population; it is usually paroxysmal and rarely life-threatening but can impact on quality of life due to troublesome symptoms.²