What is Supraventricular Tachycardia (SVT)?

Supraventricular tachycardia (SVT) is an abnormality in the timing or pattern of your heartbeat. The heart may beat very rapidly or erratically, affecting its ability to pump blood throughout the body. Supraventricular tachycardia, a type of dysrhythmia, originates in the atria, or upper chambers of the heart.

Supraventricular tachycardia is a common form of heart arrhythmia in children and adults. Infrequent occurrences are only rarely associated with serious medical problems. 

The three most common types of SVT heart conditions are :

Atrial fibrillation (AFib): This form of SVT occurs when the atria quiver, or “fibrillate,” instead of beating normally. It’s the most common dysrhythmia. Untreated, AFib leads to an increased risk of developing blood clots and stroke.

Paroxysmal supraventricular tachycardia (PSVT): In this condition, the heart’s sinus node “short circuits,” causing the heart to beat more frequently than normal. Rapid heart rate episodes can last minutes to hours.

Atrial flutter (causing atrial tachycardia): Typical atrial flutter results from a “short-circuit” in the right atrium, which causes the atria to beat at almost 300 beats per minute while the lower chamber of the heart (ventricle) beats at a slower rate (75-150 bpm). Like AFib, atrial flutter typically affects elderly patients and those with other types of heart disease, and it can increase the risk of stroke.

Baptist Health is known for advanced, superior care for patients with heart disease and the diagnosis, management and treatment of supraventricular tachycardia. You will appreciate timely appointments and a professional, friendly atmosphere where we take time to listen to your concerns. At Baptist Health, you have access to the region’s most comprehensive, multidisciplinary team of specialists and innovative therapies, including many available only through specialized clinical trials. In every way, we work to demonstrate the utmost in excellent care to those who trust us with their health.

Signs and Symptoms

Supraventricular tachycardia may not cause symptoms, or symptoms may be mild and irregular. When they do occur, signs of supraventricular tachycardia symptoms can include:

• A fluttering, skipping or pounding sensation in the chest, known as palpitations
• Chest pressure or pain
• Dizziness
• Fainting spells
• Fatigue
• Lightheadedness
• Shortness of breath
• Sweating

Symptoms can occur suddenly, without warning. They can last minutes or even days at a time, and then end just as abruptly. You may go long periods between outbreaks of symptoms. 

Supraventricular Tachycardia Diagnosis

Some types of SVT, like atrial fibrillation, can be dangerous, so early diagnosis is critical. To determine if someone has SVT, we use advanced technology to effectively diagnose, inform treatment and carefully monitor the condition. Diagnostic procedures can include:

Electrocardiogram (EKG): This test measures the electrical activity of the heart and can help determine if the heart rate is too fast or otherwise abnormal. The heart’s electrical currents are detected by 12 to 15 electrodes that are attached to the arms, legs and chest via sticky tape.

Event monitor: This portable EKG device records the heart rate when a button is pressed. It can be worn for weeks, or until symptoms occur.

Holter monitor: This portable EKG device continuously records the heart’s rhythms and is worn for 24 to 48 hours during normal activity.

Implantable loop recorder: This small device, implanted just under the skin of the chest, is automatically triggered by an irregular heart rhythm, but can also be triggered manually. It is used for continuous, long-term monitoring of the heart's electrical activity and may be worn from months to years.

Supraventricular Tachycardia Causes

Generally, SVT causes are unknown. But certain conditions and behaviors are associated with it, including:

• Alcohol abuse
• Buildup of fat and plaque on the lining of the arteries (atherosclerosis)
• Cocaine and other drug abuse
• Excessive caffeine intake
• Tobacco use

Supraventricular Tachycardia Risk Factors

Risk factors that could contribute to supraventricular tachycardia include:

Certain medications: High doses of the heart medicine digoxin or the bronchodilator theophylline may contribute to SVT.

Pregnancy: SVT sometimes occurs in pregnant women.

Previous heart surgery: SVT has been found in people who undergo surgery to the upper chambers of the heart, often to repair a congenital heart defect.

Serious health conditions: Chronic obstructive pulmonary disease, heart failure, pneumonia, thyroid disease and some metabolic problems have been linked to SVT.

Structural abnormalities: Some conditions, such as Wolff-Parkinson-White syndrome, cause extra electrical tissue to grow, creating abnormal electrical circuits that predispose the heart to arrhythmias.

Supraventricular Tachycardia Prevention

While most risk factors for SVT heart condition cannot be controlled, there are some ways to reduce your chances of developing SVT – or complications from SVT.

Practice good heart health: Watch what you eat, exercise and avoid smoking,

Take your medications as prescribed: If you have heart disease, high blood pressure, high cholesterol, diabetes or another serious health condition, be certain to take your prescribed medications as directed.

Get regular check-ups: Abnormal heart rhythms can be detected at a regular appointment, leading to faster diagnosis and treatment.

Supraventricular Tachycardia Prognosis

Unless structural heart disease is present, the prognosis for SVT is typically very good. Treatment for more serious cases of SVT, like atrial fibrillation, is necessary for continued health.

Supraventricular Tachycardia Treatment

In some cases, supraventricular tachycardia treatment is not needed. For atrial fibrillation and some cases of atrial flutter, treatment includes:

Catheter Ablation

One or more catheters are threaded through blood vessels to the heart. Electrodes at the catheter tips use heat, extreme cold or radiofrequency energy to damage (ablate) a small spot of heart tissue and create an electrical block along the pathway that’s causing atrial fibrillation or flutter.

Medication

Medications may be prescribed to prevent and treat blood clots which can lead to stroke. You may also receive medications that help regulate your heart rate and rhythm. These medications may be prescribed in conjunction with other treatments.

Supraventricular Tachycardia Complications

Rarely, if an episode of SVT heart condition lasts for several hours, the ability of the heart to pump blood throughout the body may be greatly reduced, causing heart failure.

Atrial fibrillation, and some cases of atrial flutter, carry risks of blood clots and stroke if left untreated.

Supraventricular tachycardia is rarely life-threatening. If, however, you are regularly experiencing symptoms such as shortness of breath, lightheadedness, dizziness, or fainting, you should seek medical help. These may indicate the presence of a more serious underlying condition. Supraventricular tachycardia is treated by Baptist Health providers.