Supraventricular Tachycardia (SVT) and Ventricular Tachycardia (VT)

Introduction

Supraventricular tachycardia (SVT) and ventricular tachycardia (VT) are two forms of tachyarrhythmias, meaning they are conditions characterized by an abnormally fast heart rate. Understanding the differences between these two conditions is crucial, as they have different causes, symptoms, risks, and treatments.

Supraventricular Tachycardia (SVT)

Definition

SVT refers to a group of rapid heart rhythms that originate above the ventricles, typically in the atria or the atrioventricular (AV) node. These arrhythmias cause the heart to beat excessively fast, sometimes over 150 beats per minute.

Causes

• Atrioventricular nodal reentrant tachycardia (AVNRT)
• Atrioventricular reciprocating tachycardia (AVRT), including Wolff-Parkinson-White Syndrome
• Atrial tachycardia
• Excess caffeine, stress, or alcohol
• Structural heart diseases

Symptoms

• Sudden onset of rapid heartbeat
• Palpitations
• Dizziness or lightheadedness
• Shortness of breath
• Chest discomfort

Treatment

• Vagal maneuvers (such as the Valsalva maneuver or carotid sinus massage)
• Adenosine (commonly used to stop an SVT episode in emergencies)
• Beta-blockers or calcium channel blockers (for long-term management)
• Catheter ablation (for recurrent cases)

Ventricular Tachycardia (VT)

Definition

VT is a fast heart rhythm that originates in the ventricles, the lower chambers of the heart. Unlike SVT, VT is potentially life-threatening, particularly if sustained, as it can degenerate into ventricular fibrillation, leading to cardiac arrest.

Causes

• Coronary artery disease (CAD) and heart attacks
• Structural heart disease, including heart failure
• Long QT syndrome
• Electrolyte imbalances (e.g., potassium, magnesium deficiencies)
• Drug toxicity (e.g., certain antiarrhythmics or stimulants)

Symptoms

• Rapid heartbeat
• Severe dizziness or syncope (fainting)
• Chest pain
• Shortness of breath
• Sudden cardiac arrest (in severe cases)

Treatment

• Emergency defibrillation (for unstable VT or cardiac arrest)
• Antiarrhythmic medications (e.g., amiodarone, lidocaine)
• Implantable cardioverter-defibrillator (ICD) (for high-risk patients)
• Catheter ablation (for recurrent VT)

Key Differences Between SVT and VT

Conclusion

Recognizing the difference between SVT and VT is essential for proper diagnosis and treatment. While SVT is often benign and treatable with non-emergency methods, VT requires immediate attention due to its risk of sudden cardiac death. If you experience repeated symptoms of either condition, consult a cardiologist as soon as possible.

Source recommendations

1. 2022 AHA/ACC/HRS Guideline for the Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

1. https://pubmed.ncbi.nlm.nih.gov/29084733/
2. https://www.sciencedirect.com/science/article/pii/S2405500X22010945
3. https://pubmed.ncbi.nlm.nih.gov/36017572/
4. https://www.heartrhythmjournal.com/article/S1547-5271(17)31249-3/fulltext
5. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000548

2. 2020 ESC Guidelines for the Diagnosis and Management of Atrial Fibrillation

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

3. 2019 ACC/AHA/HRS Focused Update of the 2015 Guideline for the Management of Adult Patients with Supraventricular Tachycardia

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000665
2. https://www.jacc.org/doi/10.1016/j.jacc.2019.01.011
3. https://www.ahajournals.org/doi/10.1161/cir.0000000000000311
4. https://www.jacc.org/doi/10.1016/j.jacc.2023.08.017
5. https://www.sciencedirect.com/science/article/abs/pii/S1547527123022464