Supraventricular tachycardia: defining features and principal types
THE CONTEXT
Supraventricular tachycardia (SVT) describes a group of regular tachycardias with a similar appearance on the electrocardiogram.
Features and mechanisms
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SVTs are usually narrow-complex tachycardias involving an atrial re-entry circuit or automatic focus.
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The three principal types are atrioventricular nodal re-entrant tachycardia (AVNRT), atrioventricular re-entrant tachycardia (AVRT) and atrial tachycardia.
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The term supraventricular is not strictly accurate because the ventricles also participate in the re-entry circuit in many cases.