Understanding Drugs for Supraventricular Tachycardia (SVT)

Introduction

Supraventricular tachycardia (SVT) is a condition characterized by an abnormally fast heart rhythm originating above the ventricles. It can cause palpitations, dizziness, shortness of breath, or even more severe symptoms if left untreated. This lecture explains the different drug options available to control and manage SVT.

Goals of Drug Therapy

The treatment for SVT primarily aims to:
- Slow down the rapid heart rate
- Prevent recurrent episodes
- Improve patient quality of life

Categories of Medications for SVT

1. Adenosine

   • Usually the first-line treatment in emergencies.
   • It works by temporarily blocking the electrical conduction through the atrioventricular (AV) node, effectively stopping the abnormal rhythm.
   • Given as a rapid intravenous (IV) push.

2. Beta-Blockers (e.g., Metoprolol, Atenolol, Propranolol)

   • Reduce heart rate by blocking the effects of adrenaline.
   • Used for long-term prevention of SVT episodes.
   • May not be suitable for patients with asthma or severe heart block.

3. Calcium Channel Blockers (e.g., Verapamil, Diltiazem)

   • Prevent the excessive electrical signals from passing through the AV node.
   • Used both in acute episodes (IV form) and long-term management (oral form).
   • Should be avoided in severe heart failure.

4. Antiarrhythmic Drugs (e.g., Amiodarone, Flecainide, Propafenone, Sotalol)

   • Used in cases resistant to other treatments.
   • Work by stabilizing the electrical activity of the heart.
   • Require careful monitoring due to potential side effects, such as QT prolongation.

Important Considerations

• Medication choice depends on underlying conditions (e.g., structural heart disease, electrolyte imbalances).
• Some medications require ECG and blood tests for monitoring.
• Lifestyle changes (reducing stress, caffeine, and alcohol) can improve treatment outcomes.
• In some cases, catheter ablation may be recommended if drug therapy is insufficient.

Conclusion

SVT can often be well-managed with the appropriate medications. However, choosing the right drug depends on individual patient factors. Always consult with a cardiologist to determine the best treatment plan.

If you experience frequent or severe SVT episodes, seek immediate medical attention.

Source recommendations

1. 2020 European Society of Cardiology (ESC) Guidelines for the Management of Atrial Fibrillation

1. https://www.escardio.org/static-file/Escardio/Guidelines/Documents/ehaa612.pdf
2. https://academic.oup.com/eurheartj/article/42/5/373/5899003
3. https://pubmed.ncbi.nlm.nih.gov/32860505/
4. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Atrial-Fibrillation
5. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193

2. American Heart Association (AHA) Guidelines for Supraventricular Tachycardia Treatment

1. https://www.ahajournals.org/doi/10.1161/cir.0000000000000311
2. https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia/tachycardia--fast-heart-rate
3. https://professional.heart.org/en/science-news/-/media/028ddd505f514ea2b3a4e74bb72e3557.ashx
4. https://pubmed.ncbi.nlm.nih.gov/26409259/
5. https://professional.heart.org/en/science-news/guideline-for-the-management-of-adult-patients-with-supraventricular-tachycardia