What is the management of Supraventricular Tachycardia (SVT)?

From the Guidelines

The most effective management strategy for supraventricular tachycardia (SVT) involves a combination of acute treatment with vagal maneuvers and/or adenosine, and long-term prevention with catheter ablation or daily medications such as beta-blockers, calcium channel blockers, or antiarrhythmics. For acute SVT episodes, vagal maneuvers like the Valsalva maneuver or carotid sinus massage should be attempted first, as they can terminate up to 25% of PSVTs 1. If these fail, intravenous adenosine is the first-line medication, typically starting with 6 mg given as a rapid bolus, followed by a 12 mg dose if needed.

Long-term Management Options

• Catheter ablation offers definitive treatment with success rates over 95% for most SVT types, and is considered a first-line therapy for treatment of symptomatic SVT, as it provides the potential for definitive cure without the need for chronic pharmacological therapy 1.
• Daily medications such as beta-blockers (e.g. metoprolol 25-100 mg twice daily), calcium channel blockers (e.g. diltiazem 120-360 mg daily in divided doses), or antiarrhythmics like flecainide (50-200 mg twice daily) can be used for recurrent episodes, and are particularly useful for patients who are not candidates for, or prefer not to undergo, catheter ablation 1.

Key Considerations

• Patient education on how to perform vagal maneuvers is essential for ongoing management of SVT, as it can help to avoid a more prolonged tachycardia episode and reduce the need to seek medical attention 1.
• The choice between ablation and medication depends on frequency of episodes, patient preference, and comorbidities.
• Flecainide or propafenone can be used for ongoing management in patients without structural heart disease or ischemic heart disease who have symptomatic SVT and are not candidates for, or prefer not to undergo, catheter ablation 1.

From the FDA Drug Label

In patients without structural heart disease, flecainide acetate tablets, USP are indicated for the prevention of: •paroxysmal supraventricular tachycardias (PSVT), including atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia and other supraventricular tachycardias of unspecified mechanism associated with disabling symptoms

Flecainide acetate is indicated for the prevention of paroxysmal supraventricular tachycardias (PSVT) in patients without structural heart disease.

• The use of flecainide acetate should be reserved for patients in whom the benefits of treatment outweigh the risks, due to its proarrhythmic effects.
• It is recommended to initiate therapy in a hospital setting for patients with sustained VT.
• The dosage schedule should be followed carefully to minimize the risk of proarrhythmic events 2, 2.

From the Research

SVT Management Overview

• SVT management involves various treatment options, including vagal maneuvers, adenosine, and calcium channel blockers 3, 4, 5, 6, 7
• The choice of treatment depends on the patient's condition, medical history, and the severity of the SVT episode

Vagal Maneuvers

• Vagal maneuvers, such as the Valsalva maneuver and carotid sinus massage, are often used as the first line of treatment for SVT 5, 7
• The modified Valsalva maneuver has been shown to be more effective than the standard Valsalva maneuver and carotid sinus massage in terminating SVT 5
• Vagal maneuvers are successful in terminating SVT in approximately 25% of cases 7

Adenosine and Calcium Channel Blockers

• Adenosine and calcium channel blockers are commonly used to treat SVT, with adenosine being the preferred initial treatment in many cases 3, 4, 6
• Calcium channel blockers, such as verapamil and diltiazem, have been shown to be as effective as adenosine in converting SVT to sinus rhythm, with fewer side effects 4, 6
• The use of slow infusion of calcium channel blockers has been shown to be safe and effective in treating SVT, with minimal risk of hypotension 4

Treatment Comparison

• Studies have compared the efficacy of adenosine and calcium channel blockers in treating SVT, with mixed results 3, 4, 6
• A study found that calcium channel blockers had a higher conversion rate than adenosine, although the difference was not statistically significant 4
• Another study found that adenosine and calcium channel blockers had similar conversion rates, with adenosine having more minor adverse effects 6

Patient Considerations

• Patient factors, such as medical history and hemodynamic stability, should be taken into account when choosing a treatment for SVT 6
• Electrical cardioversion may be necessary for patients who are hemodynamically unstable or have not responded to other treatments 6