Supraventricular tachycardia (SVT) an abnormal heartbeat, or arrhythmia, that is caused by an abnormal firing of electrical signals in the atria or the AV node. SVTs include several different types of arrhythmias such as atrial fibrillation, atrial flutter, atrial tachycardia, AVNRT, AVRT (WPW).
The electrical system of the heart is made up of several parts that communicate with one another to signal the heart muscle fibers when to contract. The SA node starts the signal causing the atria to contract. This signal travels through the AV node and on to the bundle of His, bundle branches causing the ventricles to contract. The flow of electrical signals is what produces a normal heartbeat.
SVTs are caused by an abnormal firing of electrical signals that interfere with the normal electrical signal pathways of the heart. Atrial fibrillation is the example of SVT shown in the images.
The rapid heartbeat caused by SVT does not allow enough time for the heart to fill before it contracts so blood flow to the rest of the body is compromised. This may lead to symptoms of dizziness, lightheadedness, and chest pain. SVT is rarely life threatening. Treatment options may include medications and ablation procedures.
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