Frequently asked questions about PSVT

1. When is PSVT diagnosed?
Paroxysmal supraventricular tachycardia (PSVT) is a rapid heart rate, initiated above the ventricles that occurs sporadically (paroxysmal). The heart rate may be 150 to 250 beats per minute (in children, the heart rate tends to be very high). There may be signs of poor perfusion. An ECG usually detects PSVT.

2. What are the symptoms of PSVT?
Symptoms may include palpitations (a sensation of feeling the heart beat), rapid pulse, anxiety, shortness of breath, or chest tightness. Additional symptoms that may be associated with this disease are fainting, dizziness, and pale color (pallor). Symptoms may start and stop suddenly and can last for a few minutes or as long as a day or two.

3. Who is most often affected by PSVT?
PSVT occurs most often in young people and infants who have normal hearts. Risks include excessive smoking, caffeine, and alcohol use. PSVT can occur with digitalis toxicity. It can be a form of a reentry tachycardia, resembling Wolff-Parkinson-White syndrome.

4. How is PSVT treated?
PSVT may resolve spontaneously. If symptoms occur or there are underlying cardiac disorders, treatment may include Valsalva maneuvers, massaging of the carotid arteries in the neck, electrical cardioversion (shock), or medications. Surgical modification of the electrical conduction pathway (the pathways in the heart that conduct the impulse to contract) may be recommended in some cases. Pacemakers designed to interrupt (override) the tachycardia may be an alternative to surgery or chronic use of medications.

5. What is a vagal or Valsalva maneuver?
These maneuvers consist of holding the breath and straining or coughing while sitting with the upper body bent forward. Occasionally, they interrupt the arrhythmia and convert the sinus rhythm back to normal.

6. What drugs are used to treat PSVT?
Adenocard (adenosine injection) is the drug recommended by the American Heart Association. Other medications that may be used include verapamil, amiodarone, sotalol, diltiazem, digoxin, procainamide, or others.

7. What prognosis is usually associated with PSVT?
PSVT is generally not life threatening unless other cardiac disorders are present.

8. What should you do if you have PSVT?
Call your health care provider if you experience your first episode of PSVT and symptoms do not end spontaneously in a few minutes. Call your health care provider if you have a history of PSVT and an episode does not resolve with Valsalva maneuver or if other symptoms accompany the rapid heart rate.

9. How can you prevent PSVT?
Avoid excessive smoking, caffeine, and alcohol use. In people at a high risk or who have had previous episodes of PSVT, medications used to treat the disorder may be given as a preventive (prophylactic) treatment.

10. How common is PSVT in children?
PSVT occurs in one out of every 250 to 1000 children and is the most common symptomatic tachyarrhythmia in childhood. Most infants diagnosed with PSVT outgrow it by 10 months but may have a recurrence between the ages of 5 and 8 years.