– Supraventricular tachycardia (SVT), also called paroxysmal supraventricular tachycardia, is defined as an abnormally fast heartbeat. It’s a broad term that includes many forms of heart rhythm problems (heart arrhythmias) that originate above the ventricles (supraventricular) in the atria or AV node.
-Supraventricular tachycardia occurs when faulty electrical connections in the heart or abnormal areas of electrical activity trigger and sustain an abnormal rhythm. When this happens, the heart rate accelerates too quickly and doesn’t allow enough time for the heart to fill before it contracts again. These ineffective contractions of the heart may cause you to feel light-headed or dizzy because the brain isn’t receiving enough blood and oxygen.
-There are three major types of supraventricular tachycardia:
- Atrioventricular nodal reentrant tachycardia (AVNRT). This is the most common type of supraventricular tachycardia in both males and females of any age, although it tends to occur more often in young women.
- Atrioventricular reciprocating tachycardia (AVRT). AVRT is the second most-common type of supraventricular tachycardia. It’s most commonly diagnosed in younger people.
- Atrial tachycardia. This type of supraventricular tachycardia is more commonly diagnosed in people with coexisting heart disease. Unlike AVNRT and AVRT, which always involve the AV node as part of the faulty connection, atrial tachycardia doesn’t involve the AV node.
-Over time, untreated and frequent episodes of supraventricular tachycardia may weaken the heart and lead to heart failure, particularly if you have other coexisting medical conditions.
-Most people with supraventricular tachycardia do not require medical treatment. However, if you experience prolonged or frequent episodes, your doctor may recommend or try:
- Carotid sinus massage.Your doctor may try this type of massage that involves applying gentle pressure on the neck — where the carotid artery splits into two branches — to release certain chemicals that slow the heart rate. Don’t attempt to do this on your own as it may cause blood clots that could lead to a stroke, or heart or lung injury.
- Vagal maneuvers.You may be able to stop an episode of SVT by using particular maneuvers that include holding your breath and straining, dunking your face in ice water, or coughing.
These maneuvers affect the nervous system that controls your heartbeat (vagus nerves), often causing your heart rate to slow.
- If you’re unable to stop an episode of SVT on your own using vagal maneuvers, your doctor may use cardioversion, which can be conducted as a procedure or by using medications.
In the procedure, a shock is delivered to your heart through paddles or patches on your chest. The current affects the electrical impulses in your heart and can restore a normal rhythm.
- If you experience frequent episodes of SVT, your doctor may prescribe medication to control your heart rate or restore a normal heart rhythm. It’s very important to take any anti-arrhythmic medication exactly as directed by your doctor in order to minimize complications.
If maneuvers or medications are not effective to control frequent episodes of SVT catheter ablation is recommended as permanent solution of SVT.
- Catheter ablation.In this procedure, your doctor threads one or more catheters through your blood vessels to your heart. Electrodes at the catheter tips can use heat, extreme cold or radiofrequency energy to damage (ablate) a small spot of heart tissue and create an electrical block along the pathway that’s causing your arrhythmia.