DESCRIPTION

• Supraventricular tachycardia (SVT) is the generic term for paroxysmal, regular supraventricular tachyarrhythmias.
• The tachycardia may be due to atrioventricular nodal reentrant tachycardia (AVNRT), AV reentrant tachycardia (AVRT), junctional tachycardia, or atrial tachycardia.
• The term is not generally used for atrial fibrillation or flutter, even if they are paroxysmal, but rather for other usually regular, narrow QRS arrhythmias that occur paroxysmally.
• Synonym(s): Paroxysmal atrial tachycardia (PAT) (this term is now obsolete)

Pregnancy Considerations

Pregnancy is not contraindicated, but SVTs may be more frequent and precipitated by pregnancy.

EPIDEMIOLOGY

SVT is common. The prevalence depends on the population studied. SVT is more common in younger groups but can present at any age.

RISK FACTORS

None

ETIOLOGY

Dual AV nodal pathways, accessory pathway, junctional automaticity, atrial reentry, or automaticity

COMMONLY ASSOCIATED CONDITIONS

AVNRT and AVRT are usually isolated conditions. Other atrial tachycardias may be associated with structural heart disease.

Outline

• Description
  • Pregnancy Considerations
• Epidemiology
• Risk Factors
• Etiology
• Commonly Associated Conditions

Signs and symptoms:

• Palpitations
• Dyspnea
• Dizziness
• Syncope
• Fatigue (sometimes related to drug therapy)
• Chest pain
• Diaphoresis
• Polyuria (usually after tachycardia)

DIAGNOSTIC TESTS & INTERPRETATION

• EKG: Morphology depends on arrhythmia substrate. See topics addressing specific SVTs.
• Electrophysiologic study: Required if undergoing catheter ablation

Lab

None

DIFFERENTIAL DIAGNOSIS

• AVNRT
• AVRT
• Junctional tachycardia
• Atrial tachycardia
• Atrial flutter with 2:1 atrioventricular (AV) conduction

Outline

• Information
• Diagnostic Tests & Interpretation
  • Lab
• Differential Diagnosis

• Treatment depends on arrhythmia substrate. See the topics addressing specific SVTs.
• Watch for atrial fibrillation if adenosine is used and accessory pathway is present because rapid AV conduction over the accessory pathway can occur and lead to cardiac arrest.
• For patients with structurally normal hearts, "bolus" oral doses of flecainide (300 mg) or propafenone (600 mg) can be used to acutely terminate SVTs on an intermittent basis so that daily drug administration can be avoided.

ADDITIONAL TREATMENT

General Measures

• Recording of 12-lead EKG during tachycardia and during termination of tachycardia is extremely important to help with diagnosis.
• Due to the problems of long-term drug administration (adverse drug reactions, problem of multiple daily doses/noncompliance, and failure at some time over years of treatment), catheter ablation has emerged as one of the treatments of choice for (recurrent) atrial flutter, atrial tachycardia, AVNRT, and AVRT (Wolff-Parkinson-White syndrome), especially the latter if atrial fibrillation is present.
• The procedure can be performed safely with a low risk of complications; over the long term, it improves quality of life compared with drug therapy and is likely cost-effective.
• For a single episode, a conservative approach may be adopted, including observation without drug therapy.
• Patient education about nature of SVT and treatment options is vital.

SURGERY

Although surgery has been undertaken in the past for SVTs, it has been superseded by catheter ablation. Surgical treatment of SVTs is now primarily of historical interest.

IN-PATIENT CONSIDERATIONS

Admission Criteria

• Patients with SVT usually do not need to be admitted.
• Admission is warranted if SVT is incessant, or if there is a life-threatening associated problem, such as atrial fibrillation with rapid conduction over an accessory pathway (shortest preexcited RR interval 250 ms).

Outline

• Additional Treatment
  • General Measures
• Surgery
• In-Patient Considerations
  • Admission Criteria

FOLLOW-UP RECOMMENDATIONS

Patient Monitoring

• General medical care if on drugs
• If cured by catheter ablation, none required; SVTs are rarely associated with hypotension
• Cardiac arrest can occur if there is rapid conduction over the accessory pathway during atrial fibrillation.

PATIENT EDUCATION

• Relates to treatment options, especially opportunity for cure with catheter ablation
• Vagal maneuvers to terminate arrhythmia
• Activity:
  • No specific recommendations regarding activity, although SVTs can occasionally be precipitated by exercise and catecholamine increase

PROGNOSIS

Excellent

Outline

• Follow-Up Recommendations
  • Patient Monitoring
• Patient Education
• Prognosis

CODES

ICD9

427.0Paroxysmal supraventricular tachycardia

SNOMED

• 6456007 supraventricular tachycardia (disorder)
• 67198005 paroxysmal supraventricular tachycardia (disorder)

ADDITIONAL READING

• ACC/AHA/ESC Guidelines for the management of patients with supraventricular arrhythmias–executive summary. J Am Coll Cardiol. 2003;8:1493–1532.
• Ganz LI, Friedman PL. Supraventricular tachycardia. N Engl J Med. 1995;332:162–173.
• Morady F. Radio-frequency ablation as treatment for cardiac arrhythmias. N Engl J Med. 1999;340:534–544.

Peter Ott

Andrew E. Epstein