Supraventricular tachycardia is a condition where the heartbeat is abnormally fast.
It can happen to anyone at any age and often occurs for the first time in children or young adults.
In most cases, supraventricular tachycardia is harmless. It doesn’t usually last long and can settle without treatment.
Why it happens
Some people are born with an abnormality of the heart’s natural ‘wiring’ or conduction system. This allows a short circuit to develop. Under certain circumstances, this allows the heart to race very fast.
One example of this is Wolff-Parkinson-White syndrome. This is where there’s an abnormal electrical connection between the:
- atria (upper heart chambers), and
- the ventricles (lower heart chambers)
Some people with this condition can develop supraventricular tachycardias. This is because of this short circuit.
Symptoms of supraventricular tachycardia
If you have supraventricular tachycardia, you’ll usually feel your heart racing in your chest or throat.
The heart rate is usually between 140 to 180 beats per minute but can be as high as 250. A normal heartbeat should be 60 to 100 beats per minute at rest.
During a supraventricular tachycardia, the heart muscle contracts very fast. This means that it cannot relax properly between contractions to fill with blood. This reduces the amount of blood being pumped around the body.
Therefore, you may also feel:
- chest pain
- fatigue (tiredness)
On rare occasions, you may faint because of a drop in blood pressure.
These symptoms vary in length and frequency.
Diagnosing supraventricular tachycardia
If your doctor thinks that you might have supraventricular tachycardia, you’ll be referred for tests. These can include an:
Causes of supraventricular tachycardia
Common causes of supraventricular tachycardia in people at risk of the condition include:
- a change in posture
- some medications
- recreational drugs
Treating supraventricular tachycardia
The treatment for supraventricular tachycardia varies from person to person. It depends on:
- the type of supraventricular tachycardia you have
- your symptoms
- treatment of any underlying cause
- your age
- your overall health
Types of treatment
Supraventricular tachycardia treatments focus on controlling the rate and rhythm of the heart. They include:
- medication, like beta blockers and other anti-arrhythmic drugs
- electric shock treatment (DC cardioversion) in an urgent case
- radiofrequency ablation