What is supraventricular tachycardia?
Supraventricular tachycardia is a heart rhythm disorder. It is characterized by an accelerated heart rate, which occurs in the atrioventricular node.
This heart condition causes the heart to suddenly beat much faster than normal. This type of tachycardia is caused by faulty electrical impulses in the upper part of the heart, instead of the ventricles (the lower chambers of the heart).
Supraventricular tachycardia refers to any non-ventricular tachycardia, such as:
- Sinus tachycardia
- Ectopic atrial tachycardia
- Junctional tachycardia
- Atrial fibrillation
- Atrial flutter
- Atrioventricular nodal reentrant tachycardia (AVNRT)
- Paroxysmal supraventricular tachycardia (PSVT)
Supraventricular tachycardia may affect people who have no other heart disease.
Prognosis of supraventricular tachycardia
For healthy people, supraventricular tachycardia is usually a non-life-threatening condition. Usually, they will not need any treatment, as the episodes will come and go on their own.
Symptoms of supraventricular tachycardia
During an episode the patient may experience the following symptoms:
- Shortness of breath (dyspnea)
- Temporary loss of consciousness
- Chest pain
- A tingling sensation and other types of paresthesia
- Rapid breathing (polypnea)
This type of tachycardia usually causes a regular rapid heartbeat that suddenly changes from 75 to more than 200 bpm. Episodes may last from a few minutes to 48 hours.
Medical tests for supraventricular tachycardia
If you have an episode during an exam, the cardiologist will check the patient’s heartbeat and then order some other tests, such as:
- An electrocardiogram (ECG).
- Holter monitor.
- Episode monitor.
- Implantable cycle recorder.
If the specialist does not detect arrhythmia during the above tests, he may try to provoke it with other tests such as:
- Stress test.
- Tilt table test.
- Electrophysiological analysis and mapping.
What are the causes of supraventricular tachycardia?
Supraventricular tachycardia is mainly caused by a malfunction of the electrical signals between the ventricles and the atria. The atria speed up, causing a faster heartbeat. When the heartbeats are too close to each other, they are less efficient: the amount of blood pumped around the body is less than needed. This ends up lowering blood pressure.
An episode of SVT can arise after a fairly intense exercise session. As a consequence, athletes, especially those at a competitive level, have to keep their heart under control.
Can it be prevented?
It is important to know what the triggers of supraventricular tachycardia episodes are so that you can prevent them and try to avoid them. Some tips are:
- Follow a heart-healthy diet.
- Increase physical activity.
- Avoid smoking.
- Maintain a healthy weight.
- Limit or avoid alcohol consumption.
- Reduce stress.
- Get plenty of rest.
- Avoid the use of stimulant drugs, such as cocaine and methamphetamines.
In the cases of people who have already suffered some episode of this pathology some preventive recommendations are:
- Avoid drinking large amounts of caffeine.
- Keep a diary to identify triggers.
- Monitor cardiac rate, activity and symptoms at the time of a supraventricular tachycardia episode.
Treatments for supraventricular tachycardia
There are several options for treating supraventricular tachycardia:
- Vagal maneuvering: their goal is to activate the vagus nerve, which slows the heart. They are most effective when performed at the beginning of an episode. It is best to do vagal maneuvers under medical supervision, although if the patient suffers frequent episodes of tachycardia, his physician can teach him how to do some of them on his own.
- Electrical cardioversion: A defibrillator delivers small electrical shocks to the chest to restore a normal heartbeat. This may be used if vagal maneuvers do not work.
- Radiofrequency ablation: the heart tissue and heart channels that contribute to supraventricular tachycardia are destroyed by radiofrequency. It may be the best option for people who suffer from frequent episodes.
- Cryoablation: the same principle as radiofrequency ablation, but here an extremely low temperature is used to destroy the tissues. The process is performed in two steps. In the first step, the tissues are brought to -10 ° C. If everything goes as it should, then the second step is to further lower the temperature to -73°C, where the tissue is permanently dead.
What specialist treats it?
The specialist in charge of diagnosing and treating supraventricular tachycardia is a cardiologist.