Paroxysmal Supraventricular Tachycardia

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Contents 1 More Specific Terms 2 Introduction 3 Etiology 4 Clinical-manifestations 5 Diagnostic-procedures 6 Management 7 More General Terms 8 References

More Specific Terms

• AV nodal re-entrant tachycardia (AVNRT)
• orthodromic AV reciprocating tachycardia
• sinus node re-entrant tachycardia
• Wolff-Parkinson-White (WPW) syndrome

Introduction

• Regular narrow-complex tachycardia with an abrupt onset & termination.

Etiology

• AV nodal re-entrant tachycardia (most common in adults)
• orthodromic AV reciprocating tachycardia (most common in children)
• Wolf-Parkinson-White syndrome ( WPW)

Clinical-manifestations

• palpitations
• lightheadedness
• syncope or presyncope
• neck-pounding is associated with AV nodal re-entrant tachycardia

Diagnostic-procedures

• electrocardiogram:

• narrow-complex tachycardia with rate of 130-240/min
• a short R-P or P wave within ST segments suggests re-entry with

• anterograde conduction through AV node
• retrograde conduction through bypass tract

• P wave after T wave: no accessory conduction
• no P wave: re-entry simultaneously activates atria & ventricles [2]

• event recorder better than HOLTER
• electrophysiologic testing

Management

• wide QRS complex: see wide complex tachycardia
• narrow QRS complex

• generally a benign arrhythmia:

• treatment indicated only for symptomatic patients
• exception is patients with WPW

• acute measures

• consider vagal maneuvers

• carotid sinus massage* is most common maneuver

• adenosine 6 mg IV push, if no response in 1-2 min, 12 mg IV, push (may repeat once)
• normal or elevated blood pressure, block AV node

• verapamil 2.5-5 mg IV, then 5-10 mg IV or diltiazem
• beta-blocker
• digoxin

• digoxin, amiodarone, diltiazem if LVEF < 40%
• low or unstable blood pressure - synchronized cardioversion

• electrophysiologic testing with catheter ablation

• significant hemodynamic compromise during tachycardia
• syncope or presyncope
• PSVT with evidence of pre-excitation ( WPW)

• long-term pharmaco-therapy

• beta-blocker
• calcium channel blocker
• short acting agents may be used at onset of tachycardia

• propranolol 20 mg
• verapamil 80 mg

• * Contraindicated in:

• elderly
• patients with carotid bruits
• bilateral carotid sinus massage should never be performed

More General Terms

• supraventricular tachycardia (SVT)

References

1. Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 105,182
2. Medical Knowledge Self Assessment Program (MKSAP) 11, 14, American College of Physicians, Philadelphia 1998, 2006
3. American Heart Association

paroxysmal supraventricular tachycardia (PSVT)