Supaventricular tachycardias (SVT) are common rapid heart rhythms that can occur suddenly, without warning. They can cause the heart to beat up to 200 bpm. These heart rhythm disturbances are caused by duplication of the heart’s electrical circuitry. Although this duplication occurs even before birth, patients may not experience arrhythmias until they reach the age of 20 or 30, or even later in life.
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What Happens During SVT?
During an SVT the heart’s normal electrical signals travel from the upper heart chambers to the lower heart chambers and then utilizing the duplicate electrical circuit, the signals circle around back up to the top of the heart chambers. The reentry loop of heart beats allows the heart to beat rapidly without he body’s ability to regulate it.
Types of SVT
Types of SVT include:
- Atrioventricular nodal reentrant tachycardia (AVNRT) – Electrical signals that travel around the AV node in a circular motion, as if going around a racetrack.
- Atrioventricular reciprocating tachycardia (AVRT) – Electrical signals go down one staircase from the top chamber to the bottom chamber and then takes the second staircase from the bottom chamber and back up to the upper chamber. This condition is sometimes called Wolf-Parkinson-White or WPW syndrome. These arrhythmias are usually genetically acquired and range in seriousness from benign symptoms to even fatal events.
SVT usually has no symptoms and can start and end quickly. Similar to AF and AFL, symptoms can include:
- Heart palpitations
- Fast pulse
- Chest pain
- Lightheadedness and fainting
The common first-line approach to therapy are medications such as beta-blockers and calcium channel blockers. These medications can sometimes suppress and slow the arrhythmia, but they are not curative. The standard approach for symptomatic SVT is a minimally invasive definitively curative catheter –based approach called an ablation procedure. By placing a catheter in the heart experts at the Heart Rhythm Center at Sinai Hospital can locate the extra electrical pathways and melt them away preventing any further events of fast heart rhythms.
For a consultation with one of our Heart Rhythm Specialists and a discussion of the right therapy for your arrhythmia please call 410-601-WELL.