What is the treatment for supraventricular tachycardia (SVT)?

Treatment for Supraventricular Tachycardia (SVT)

The modified Valsalva maneuver is the most effective first-line treatment for hemodynamically stable SVT, followed by intravenous adenosine if vagal maneuvers fail, with catheter ablation being the recommended definitive treatment for recurrent SVT. 1, 2, 3

Acute Management Algorithm

For Hemodynamically Stable Patients:

1. First-line: Vagal Maneuvers (Class I, Level B-R)

   • Modified Valsalva maneuver is most effective (43% conversion rate) 2, 3
   • Other options include standard Valsalva or carotid sinus massage
   • Application of ice water to face can be effective (96% success in one study) 4

2. Second-line: Adenosine IV (Class I, Level B-R)

   • Highly effective (91% conversion rate) 3
   • Recommended dosing per FDA label 5
   • Short half-life makes it safer than other options
   • Common side effects: flushing, chest discomfort, dyspnea, headache

3. Third-line: IV Calcium Channel Blockers or Beta Blockers (Class IIa, Level B-R)

   • Verapamil IV (88% conversion rate) 6
   • CAUTION: Verapamil is contraindicated in patients with:
     • Severe left ventricular dysfunction (EF <30%)
     • Moderate to severe heart failure
     • Ventricular dysfunction with concurrent beta-blocker use 7
     • Accessory pathway (Wolff-Parkinson-White syndrome) 7

4. Fourth-line: Synchronized Cardioversion (Class I, Level B-NR)

   • For patients who fail pharmacological therapy

For Hemodynamically Unstable Patients:

1. Immediate Synchronized Cardioversion (Class I, Level B-NR)
   • First-line treatment for patients with hypotension, altered mental status, or signs of shock

Long-term Management

1. Catheter Ablation (Class I, Level B-R)

   • Recommended for recurrent, symptomatic SVT 1
   • Success rates of 94.3-98.5% 3
   • Lower success rates in patients with structural heart disease like Ebstein's anomaly 1

2. Pharmacological Options

   • Beta blockers (metoprolol, propranolol) - first-line for ongoing management 1
   • Calcium channel blockers (verapamil) - alternative for patients without heart failure 1
   • Flecainide - for prevention of PSVT in patients without structural heart disease 1
   • Antiarrhythmic therapy (amiodarone, disopyramide) for supraventricular arrhythmias (Class IIa, Level B) 1

Special Considerations

• Multiple accessory pathways are present in nearly 50% of patients with Ebstein's anomaly 1
• Avoid verapamil in patients with accessory pathways (WPW) due to risk of accelerated conduction and ventricular fibrillation 7
• Adenosine contraindications include second/third-degree AV block, sick sinus syndrome, bronchospastic lung disease, and hypersensitivity 5
• Regular monitoring with ECG and Holter monitoring is necessary for patients with recurrent SVT 1
• Recurrence rates are similar between adenosine and verapamil treatments 6

Common Pitfalls

• Misdiagnosis of rhythm: Administering verapamil for wide-complex tachycardia of ventricular origin can cause cardiovascular collapse 6
• Inadequate vagal maneuver technique: Modified Valsalva is superior to standard techniques 2
• Failure to recognize accessory pathways: Can lead to inappropriate treatment and adverse outcomes 1
• Underestimating hemodynamic impact: Even "stable" patients may deteriorate with certain medications
• Ignoring underlying structural heart disease: Important to evaluate for conditions that may affect treatment choice

Regular follow-up with a cardiologist is essential for patients with recurrent SVT, with catheter ablation being the most effective long-term solution for preventing recurrences.