Paroxysmal supraventricular tachycardia is best defined as the occasional rapid heart rate. In normal cases, the contractions of the heart’s ventricles and atria are done in a coordinated manner. An electrical signal originating in the sinoatrial node tells the atria to contract as the signal moves through the upper chambers of the heart. This condition begins with the events occurring in the ventricles. Infants and young people are most often affected.
This condition can be caused by several different things. Digitalis toxicity and certain medical conditions, such as Wolff-Parkinson-White syndrome can cause this condition. Other possible causes may include:
- Caffeine use
- Alcohol use
- Illicit drug use
Symptoms may begin and end suddenly, and may last anywhere from a few minutes to a few hours. If the symptoms are lasting for more than half a day, the condition is referred to as incessant paroxysmal supraventricular tachycardia. Symptoms may include:
- Shortness of breath
- Chest tightness
- Rapid pulse
If the patient has a physical examination during an episode, they will have rapid heart rate. Their heart rate may be anywhere from 150 to 250 beats per minute. Children’s heart rates will be very high in most cases. Patients may show signs of having poor blood circulation. In between episodes, the patient’s heart rate will be normal, between 60 and 100 beats per minute.
A diagnostic test referred to as an electrocardiogram can be done during episodes to diagnose this condition. Another test known as electrophysiology study is often performed to make an accurate diagnosis and to aid in creating the best treatment plan.
This condition tends to be sporadic, so using a 24-hour Holter monitor can be beneficial. A loop recorder can be used for longer recording periods.
Patients who are not experiencing symptoms may not need any treatment. Treatment may be necessary if the patient has symptoms or another heart disorder. Valsalva maneuver, a technique that can be used during an episode, can interrupt the fast heartbeat. The patient will sit bending their upper body forward and cough, or the patient will be asked to strain like they would when attempting a bowel movement and hold their breath.
It may be sometimes helpful to splash ice water on the face during an episode.
Emergency treatment of this condition may include:
- Intravenous medications, such as verapamil and adenosine. Other medications may be beneficial, such as beta-blockers, procainamide, and propafenone
- Electrical cardioversion may also be beneficial in restoring rapid heartbeats back to normal using an electric shock
Long-term treatment of this condition may include:
- Radiofrequency catheter ablation
- Daily medications, such as flecainide, sotalol, propafenone, moricizine, and amiodarone
- Certain surgical procedures
Prognosis and Complications
This condition is usually not life-threatening. However, if the patient has other pre-existing heart disorders, it could be. The primary complication associated with this condition is the patient having an increased risk of heart failure.
MedlinePlus. (2010). Paroxysmal Supraventricular Tachycardia. Retrieved on September 14, 2010 from MedlinePlus: https://www.nlm.nih.gov/medlineplus/ency/article/000183.htm
University of Maryland Medical Center. (2008). Paroxysmal Supraventricular Tachycardia. Retrieved on September 14, 2010 from the University of Maryland Medical Center: https://www.umm.edu/ency/article/000183.htm