Supraventricular Tachycardia
Supraventricular tachycardia (SVT) is a group of rapid heart rhythms starting above the ventricles. Many re-entry episodes begin and stop abruptly, but not every fast pulse is SVT.
Key takeaways
- A rapid regular heartbeat may accompany pounding in the neck, light-headedness, breathlessness or chest discomfort.
- ECG during symptoms is the best way to classify the rhythm and distinguish it from sinus tachycardia, atrial flutter or ventricular rhythm.
- Acute treatment and recurrence prevention depend on rhythm mechanism, stability, heart disease and patient preference.
Catalogue matches do not confirm SVT or indicate that an AV-node medicine is safe during an episode.
What can trigger or mimic SVT?
Episodes may occur without a trigger, while stimulants, thyroid disease, fever, anaemia and dehydration can cause or worsen a fast pulse. The abrupt pattern and rhythm tracing are more informative than a fixed rate threshold.
How can episodes be managed?
Clinician-taught vagal manoeuvres may help selected stable re-entry SVT. Verapamil has specific acute or preventive roles but can be dangerous with low blood pressure, some heart failure or uncertain broad-complex rhythms. Catheter ablation may offer definitive treatment for recurrent symptomatic SVT.
When to seek urgent care
Seek emergency care for a rapid heartbeat with fainting, severe chest pain, marked breathlessness, confusion or ongoing deterioration. A first sustained episode also needs prompt rhythm assessment.