Supraventricular Tachycardia

What is supraventricular tachycardia?

Supraventricular tachycardia (SVT) is an abnormally fast heart beat that originates from the top chambers of the heart (atria), but unlike atrial fibrillation, the heart rate is often steady and regular. In most cases, episodes of SVT are usually harmless and will often self-terminate without the need for treatment. However, you should seek medical advice if you have prolonged episodes of SVT.

What are the symptoms of supraventricular tachycardia?

The most common symptom of SVT are palpitations described as a rapid heartbeat. In some patients these may be associated with:

• dizziness,
• breathlessness or
• chest tightness.

Even though the heart can beat at very fast rates, SVTs are usually not life threatening. There are a number of different types of SVT which include having either an extra ‘wire’ in your heart which can ‘short circuit’ to cause symptoms or having an area of the upper chambers that triggers independently to the rest of the heart.

What assessment will I need if I have SVT or suspected SVT?

If you have had a previous admission to the hospital with an SVT then your cardiologist will already have the diagnosis and will require only to perform an ECG and scan of your heart (echocardiogram) to ensure that your heart is structurally normal. Your cardiologist will then be able to advise you on the best treatment options for supraventricular tachycardia. If the diagnosis is not clear but SVT is suspected then you will need ambulatory ECG monitoring to try and capture an episode in addition to an echocardiogram.

What are the treatments for Supraventricular Tachycardia?

There are a number of different approaches to the treatment of supraventricular tachycardia which can to be tailored to your individual circumstances.SVTs are potentially curable with a small operation called catheter ablation and for patients who are experiencing frequent symptoms this is the treatment of choice.

The procedure is invasive and involves the insertion of catheters, or fine wires, to the heart through the veins at the top of the leg. There are electrodes at the tip of the wires which detect electrical signals from different parts of the heart. Radio waves are used to create heat which destroys (ablates) the electrical signals that are responsible for triggering the SVT.

The procedure normally only takes a couple of hours and is safe with a high chance of success, usually greater than 95% for most patients. There are rare risks including the risk of needing a pacemaker in less than 1% of cases.

In patients with less frequent symptoms medication can be used to control the heart rhythm. This may be in the form of regular, daily medication to prevent episodes or single doses to take during an attack to try and stop it.

The Cardiologists here at the London Cardiac group are experts in the treatment of SVTs and are highly trained to assess all patients and perform large volumes of ablations for SVTs.