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Paroxysmal Supraventricular Tachycardia
(PSVT)

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What is paroxysmal supraventricular tachycardia (PSVT)?

Normally, an electrical signal is generated in special pacemaker cells in the upper chamber (atrium) of the heart. This impulse causes the atrium to beat in a coordinated fashion and push blood into the ventricles (the lower heart chambers). The electrical signal continues to a junction box between the atrium and ventricle (the AV node), where there is a slight delay. This allows the atrium to contract and send blood to the ventricle. The signal continues throughout the ventricles and causing them to beat and push blood to the body.

In paroxysmal supraventricular tachycardia (PSVT), abnormal conduction of that electricity causes the atrium, and secondarily the ventricles, to beat very rapidly. It is paroxysmal, because the rapid rate can occur sporadically and without warning. It may last a few seconds or many hours. Often the PSVT resolves before the patient reaches a healthcare provider. The abnormal conduction pathways may occur anywhere in the atrium or around the AV node.

PSVT was once also called paroxysmal atrial tachycardia or PAT. As more has been learned about the electrical wiring of the heart, terminology has changed, and the term PAT is more often reserved for a specific type of circular electrical conduction pattern occurring in the true atrial tissue, and not the AV node.

Regardless of the terminology, the rhythm disturbance occurs in the AV node, or in the atrium above, and should not be confused with ventricular tachycardia, which arises from the ventricle and is life-threatening.

Picture of the interior of the heart and chambers of the heart

What are the symptoms of paroxysmal supraventricular tachycardia (PSVT)?

PSVT often presents with the complaints of palpitations described as a rapid heart rate often felt in the throat and may be associated with: