SVT (Supraventricular Tachycardia): Causes, Symptoms, Diagnosis & Treatment Explained
Introduction
SVT (Supraventricular Tachycardia)
Supraventricular Tachycardia (SVT) is a cardiac arrhythmia characterized by an abnormally rapid heart rate that usually originates in the atria or atrioventricular (AV) node above the ventricles. The heart rate typically ranges from 150-250 beats per minute and starts and stops suddenly.
Definition
SVT is a fast, regular heart rhythm caused by abnormal electrical impulses in the upper chambers of the heart.
Types of SVT(Supraventricular Tachycardia)
- AVNRT (Atrioventricular Nodal Re-entrant Tachycardia) – the most common type
- AVRT (Atrioventricular Re-entrant Tachycardia) – includes Wolff–Parkinson–White (WPW) syndrome.
- Atrial tachycardia
- Atrial flutter (sometimes grouped under SVT)
Causes
- Re-entry of electrical impulses
- Congenital accessory pathways (e.g., WPW)
- Stress, anxiety
- Excess caffeine, alcohol, or smoking
- Electrolyte imbalance
- Heart disease or post–cardiac surgery
Risk Factors
- Young adults and females
- Congenital heart conditions
- Thyroid disorders
- Use of stimulants or certain medications
Diagnosis
- ECG (Electrocardiogram) – confirms rhythm
- Holter monitoring
- Event recorder
- Electrophysiological studies (EPS)
Management and Treatment
Acute Management
- Vagal maneuvers (Valsalva, carotid sinus massage – with caution)
- Adenosine (drug of choice in acute SVT)
- Beta-blockers or calcium channel blockers
Long-Term Management
- Anti-arrhythmic drugs
- Catheter ablation (definitive treatment in recurrent SVT)
Nursing Interventions
- Monitor vital signs and ECG
- Maintain IV access
- Administer medications as prescribed
- Educate patient on vagal maneuvers
- Reduce anxiety and provide reassurance
Prevention
Avoid caffeine, alcohol, and smoking
- Manage stress
- Adhere to prescribed medications
- Regular cardiac follow-up
Prognosis
SVT is usually not life-threatening, and most patients respond well to treatment. Catheter ablation has a high success rate and can be curative.
