|
Paroxysmal supraventricular tachycardia Causes and Risks:
Normally, the chambers of the heart (atria and ventricles) contract in a coordinated manner. The signal to contract begins in the sinoatrial node (sinus node, SA node). It is conducted through the atria (the upper heart chambers) and stimulates them to contract. It passes through the atrioventricular node (AV node), then travels through the ventricles (the larger, lower chambers) and stimulates them to contract.
Paroxysmal supraventricular tachycardia (PSVT) can be initiated in the SA node, in the atria or the atrial conduction pathways, or in the AV node. It 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 re-entry tachycardia , resembling Wolff-Parkinson-White syndrome .
Prevention:
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.
Symptoms:
Additional symptoms that may be associated with this disease: Note: Symptoms may start and stop suddenly, and can last for a few minutes or as long as a day or two.
Signs and Tests:
An examination shows a regular, rapid heart rate . 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. Between episodes of PSVT, the heart rate is normal (60 to 100). Examination is otherwise unrevealing.
- An ECG during symptoms shows PSVT.
- Continuous ambulatory monitoring or a 24-hour Holter monitor may be required to diagnose PSVT because of the sporadic nature of the disorder.
Treatment:
PSVT may resolve spontaneously. If symptoms occur or there are underlying cardiac disorders, treatment may be initiated in an attempt to interrupt the arrhythmia and convert to a normal sinus rhythm.
When their symptoms are mild, people with a history of PSVT can try a Valsalva maneuver to interrupt the episode. This consists of holding the breath and straining or coughing while sitting with the upper body bent forward. Splashing ice water on the face has been reported by some people as helpful.
A health care provider may massage the carotid arteries in the neck in an attempt to interrupt the arrhythmia. Caution--do not try this at home! This technique can cause severe slowing of the heart rate . Consult your health care provider.
Electrical cardioversion ( shock ) is successful in conversion of PSVT in many cases.
Medications that may be used to convert PSVT to a normal sinus rhythm include verapamil and adenosine. In children, verapamil is not used much, adenosine is much more common. Other medications that may be used include esmolol, Tensilon, phenylephrine, digoxin, procainamide, or others.
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.
Prognosis:
PSVT is generally not life threatening unless other cardiac disorders are present.
Complications:
Call Your Healthcare Provider:
Call your health care provider if this is the 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 .
Call your health care provider if symptoms recur frequently, or new symptoms develop.
|
