Supraventricular Tachycardia (SVT) and Its Impact on the Heart

Introduction

Supraventricular Tachycardia (SVT) is a broad term describing a group of arrhythmias that originate above the ventricles, in the atria or the atrioventricular (AV) node. It leads to a rapid heart rate, which can cause symptoms like palpitations, dizziness, shortness of breath, or even chest pain.

Causes of SVT

SVT occurs due to abnormal electrical circuits in the heart. Some common forms include: - Atrioventricular Nodal Reentrant Tachycardia (AVNRT) – The most common type, caused by a re-entry circuit near the AV node. - Atrioventricular Reentrant Tachycardia (AVRT) – Often associated with Wolff-Parkinson-White (WPW) syndrome, caused by an extra electrical pathway between the atria and ventricles. - Atrial Tachycardia (AT) – Originates from an ectopic focus in the atria, leading to excessive rapid beats.

Symptoms

The symptoms of SVT can range from mild to severe and may include: - Rapid heart rate (often over 150 bpm) - Palpitations - Dizziness or lightheadedness - Shortness of breath - Chest discomfort - Fainting (syncope), in severe cases

Diagnosis

Doctors diagnose SVT using: 1. Electrocardiogram (ECG) – The primary tool in identifying the type of arrhythmia. 2. Holter Monitor – A portable ECG that records heart activity over 24-48 hours. 3. Electrophysiology Study – A specialized test to map abnormal electrical circuits.

Treatment Options

Acute Management

• Vagal Maneuvers (e.g., carotid sinus massage, Valsalva maneuver) can help terminate SVT in many cases.
• Adenosine – A fast-acting medication that can rapidly stop SVT.
• Beta-Blockers or Calcium Channel Blockers – Used if the SVT persists.
• Cardioversion – A synchronized electrical shock used in emergency cases.

Long-Term Management

• Medications (e.g., beta-blockers, antiarrhythmics) to prevent recurrences.
• Catheter Ablation – A minimally invasive procedure to destroy the abnormal electrical pathway, considered a definitive treatment.
• Lifestyle Modifications – Avoiding caffeine, alcohol, and stress, which can act as triggers.

Possible Complications

If untreated, SVT may lead to: - Heart failure (in persistent cases) - Reduced cardiac efficiency - Increased risk of stroke, especially if atrial fibrillation is present

Conclusion

SVT is generally not life-threatening but can cause discomfort and complications if untreated. Early diagnosis and proper management, including lifestyle modifications and possible catheter ablation, can significantly improve a patient’s quality of life. If you experience frequent episodes of rapid heartbeats, consult a cardiologist for evaluation.

Source recommendations

1. American Heart Association Guidelines on Supraventricular Tachycardia

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://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
4. https://professional.heart.org/en/science-news/guideline-for-the-management-of-adult-patients-with-supraventricular-tachycardia
5. https://pubmed.ncbi.nlm.nih.gov/26399662/

2. European Society of Cardiology Guidelines on the Management of Supraventricular Arrhythmias

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Supraventricular-Tachycardia
2. https://www.ahajournals.org/doi/10.1161/cir.0000000000000311
3. https://academic.oup.com/eurheartj/article/41/5/655/5556821
4. https://www.ahajournals.org/doi/10.1161/01.cir.0000091380.04100.84
5. https://pubmed.ncbi.nlm.nih.gov/31504425/