Paroxysmal supraventricular tachycardia (PSV... Health Article

Definition

Paroxysmal supraventricular tachycardia (PSVT) is an occasional rapid heart rate. "Paroxysmal" means from time to time.

Alternative Names

PSVT; Supraventricular tachycardia

Causes, incidence, and risk factors

Normally, the chambers of the heart (atria and ventricles) contract in a coordinated manner. The contractions are caused by an electrical signal that begins in an area of the heart called the sinoatrial node (also called the sinus node or SA node). The signal moves through the upper heart chambers (the atria) and tells the atria to contract.

PSVT starts with events taking place above the lower heart chambers (ventricles). PSVT can be initiated in the SA node, in the upper heart chambers (atria), in the atrial conduction pathways, or other areas.

PSVT can occur with digitalis toxicity and conditions such as Wolff-Parkinson-White syndrome.

The condition occurs most often in young people and infants.

The following increase your risk for PSVT:

• Alcohol use
• Caffeine use
• Illicit drug use
• Smoking

Symptoms

• Anxiety
• Chest tightness
• Palpitations (a sensation of feeling the heart beat)
• Rapid pulse
• Shortness of breath

Additional symptoms that may be associated with this condition:

• Dizziness
• Fainting

Note: Symptoms may start and stop suddenly, and can last for a few minutes or several hours. A PSVT lasting more than half of the day is considered an incessant PSVT.

Signs and tests

A physical examination during a PSVT episode will show a rapid heart rate.

The heart rate may be 150 to 250 beats per minute (bpm). In children, the heart rate tends to be very high. There may be signs of poor blood circulation such as light headedness. Between episodes of PSVT, the heart rate is normal (60 to 100 bpm).

An ECG during symptoms shows PSVT. An electrophysiology study (EPS) is often necessary for an accurate diagnosis and to recommend the best treatment.

Because of the sporadic nature of the PSVT, its diagnosis may require 24-hour Holter monitoring. For longer recording periods, a "loop recorder" (with computer memory) is used.