Supraventricular Tachycardia (SVT)
What is supraventricular tachycardia (SVT)?
Supraventricular tachycardia, frequently abbreviated to SVT, is a rapid abnormal heart rhythm that begins in the upper chambers of the heart. The atria are above the ventricles, hence the term supraventricular. The term tachycardia refers to a rapid heartbeat of over 100 beats per minute.
Typically, patients have varying degrees of symptoms from SVT, but occasionally they may have no symptoms at all. Symptoms you may experience during SVT include:
- Chest pain
- Light headedness
- Shortness of breath
- Loss of consciousness (rare)
Although such symptoms may raise concern, in general, the majority of SVTs are not life threatening. Nonetheless, if any of these symptoms develop, you should contact your doctor.
A good description, keeping a diary of events and consulting a doctor who is fully aware of the condition and takes a detailed history, should lead to a correct diagnosis.
The following tests may also be used to help doctors make a diagnosis:
- A heart rhythm monitor, which can monitor the heart for 24 hours
- An event recorder, which can record for 1–2 weeks
Once an SVT is diagnosed your doctor or nurse specialist at your local hospital will discuss your treatment options with you.
Medication is used to treat many patients with SVT. Your doctor will discuss with you the most commonly used medications, including their benefits and side effects.
A special procedure called catheter ablation may also be appropriate as an alternative to medication, depending on your diagnosis. This procedure aims to cure the abnormal heart rhythm by destroying the area of extra cells causing the palpitations.
A sudden-onset, fast heart rhythm can often be stopped with simple procedures called physiological manoeuvres. These are easy and safe to perform in any setting and may stop the fast rhythm and return the heart to normal.
If when the rhythm starts you feel unwell, for example you have bad chest pain, feel very faint or find breathing difficult, call 999 for an ambulance.
It may be useful to keep a record of how frequently your SVT occurs. If you find that your symptoms worsen or the method you use to stop them no longer works, do not worry. Talk to your GP who should be able to recommend a heart rhythm specialist that you can be referred to, to discuss further treatment options.