Understanding Supraventricular Tachycardia (SVT): Symptoms, Causes, and Treatment

You’re sitting at the lunch table with your colleagues, laughing over a story someone just shared. It’s a typical afternoon—until it happens again. That strange, unsettling pounding in your chest. Your smartwatch jumps erratically between 50 and 200 BPM. You notice your hands feel a bit sweaty, and you feel slightly lightheaded. You take a deep breath, waiting for it to pass, but your heart keeps racing.

This is the third time it’s happened. Maybe it’s stress, maybe too much caffeine. But what if it’s something more?

Determined to find answers, you wear a continuous ECG monitor to track your heart’s activity beyond those fleeting moments. When you finally sit down with your cardiologist, they carefully examine the data and say, “You have SVT.”

SVT? What does that even mean? Let’s break it down and understand what’s happening inside your heart.

What is SVT?

Supraventricular Tachycardia (SVT) is a condition where the heart beats abnormally fast due to irregular electrical signals. The name comes from Latin—“Supraventricular” means “above the ventricles,” referring to the atria (the upper chambers of the heart ), while “Tachycardia” (pronounced tack-eh-CARD-ee-uh) refers to a fast heartbeat. While SVT is usually not life-threatening, it can be unsettling and, in some cases, require medical intervention.

In the U.S. alone, about 2.25 cases per 1,000 in the general population experience SVT, with nearly 89,000 new cases each year. Women are twice as likely to develop SVT as men, and individuals over 65 face five times the risk compared to younger adults.

SVT vs. Ventricular Tachycardia (VT): What’s the Difference?

Supraventricular Tachycardia (SVT) originates in the atria (upper chambers of the heart), while Ventricular Tachycardia (VT) begins in the ventricles (lower chambers). While both conditions cause a rapid heart rate exceeding 100 beats per minute, VT is generally far more serious and can lead to life-threatening complications like cardiac arrest.

SVT is generally not dangerous and is often managed with medications, as patients tend to remain stable. In contrast, VT is a medical emergency, requiring immediate intervention, often with synchronized cardioversion, to prevent it from progressing into ventricular fibrillation. The key difference lies in the location of the electrical impulses—SVT originates at or above the atrioventricular (AV) node, whereas VT starts below it in the ventricles.

Because SVT and VT can sometimes present with similar symptoms, an accurate diagnosis is crucial to ensure the right treatment approach.

Supraventricular Tachycardia

Ventricular Tachycardia

Types of SVT

1.  Atrioventricular (AV) Nodal Reentrant Tachycardia (AVNRT)

People with AVNRT often feel their heart racing suddenly, sometimes over 100 beats per minute, before it just as quickly returns to normal. This happens because of an extra electrical pathway in the heart, creating a loop that causes it to beat too soon.

While AVNRT is more common in young women, it can affect anyone at any age. Some people may not need treatment, but for those who do, options include simple physical techniques, medication, or a procedure to help restore a steady heartbeat.

2. AV Reciprocating Tachycardia (AVRT)

AVRT is the second most common type of supraventricular tachycardia (SVT). This condition occurs due to an abnormal electrical pathway connecting the upper and lower chambers of the heart, causing the heart to beat rapidly. The electrical signal moves down one pathway to the lower chambers and then loops back up through the extra pathway, creating a continuous circuit that sustains the tachycardia. It is often associated with Wolff-Parkinson-White (WPW) syndrome, a condition where an extra electrical connection in the heart can lead to episodes of rapid heart rate.

3. Atrial Tachycardia

Atrial tachycardia, the third type of supraventricular tachycardia (SVT), occurs when a specific area in the upper chambers of the heart starts sending rapid electrical signals, similar to a flashing light. These signals spread through the atria, causing an abnormally fast heartbeat. Treatment typically involves the same anti-arrhythmic medications used for atrial fibrillation, helping to regulate the heart’s rhythm and restore a normal heartbeat.

Symptoms of SVT

Many people with SVT might not notice any symptoms, but when they do, the experience can be unsettling. Some common signs include:

• Rapid heartbeat (over 100 beats per minute at rest) or a sensation of fluttering/pounding in the chest (palpitations)
• Chest discomfort or pain
• Feeling unusually tired or fatigued
• Dizziness or lightheadedness
• Excessive sweating
• Shortness of breath
• In severe cases, fainting

What Causes Supraventricular Tachycardia (SVT)?

SVT is typically triggered by abnormal electrical signals in the heart, often starting with premature beats. Some forms of SVT are hereditary, while others may result from lung conditions, certain lifestyle factors, or underlying health issues. Some common triggers include:

• High stress or anxiety levels
• Drinking too much caffeine or alcohol
• Smoking
• Poor sleep habits
• Dehydration
• Intense physical activity

Risk Factors for SVT

While SVT can happen to anyone, certain factors can make it more likely:

• Regular consumption of caffeine or alcohol
• Smoking or using recreational drugs
• Underlying conditions like heart disease, lung issues, or thyroid disorders
• Diabetes
• Pregnancy

Possible Complications

SVT isn’t usually dangerous, but if episodes are frequent or prolonged, it could lead to:

• Heart failure
• Brief loss of consciousness
• In rare cases, cardiac arrest

If you experience persistent or severe symptoms, it’s important to consult a healthcare provider for proper evaluation and management.

Diagnosing SVT

If you experience symptoms, your doctor will ask about your medical history and perform tests, such as:

• Electrocardiogram (EKG): Records the heart’s rhythm to detect abnormalities.
• Holter Monitor: A portable device that tracks heart activity for 24-48 hours.
• Event Monitor: Used for longer periods to detect irregular heartbeats.
• Electrophysiology Study: A specialized test that maps the heart’s electrical activity.

Treatment Options for SVT

Treatment for Supraventricular Tachycardia (SVT) depends on the frequency and severity of episodes. While some cases may not require intervention, your doctor may recommend the following approaches:

• Maneuvers to stop SVT.: Techniques such as the Valsalva maneuver (pushing out air but with nose and mouth closed), forceful coughing, or placing an ice pack on the face can stimulate the vagus nerve, helping to slow the heart rate. Carotid sinus massage, performed under medical supervision, may also be an option.
• Medications: Beta-blockers, calcium channel blockers, or adenosine may be prescribed to regulate heart rhythm and prevent recurrences.
• Cardioversion: If SVT episodes are severe or unresponsive to other treatments, a controlled electrical shock may be used to restore a normal heart rhythm.
• Catheter Ablation: A minimally invasive procedure that targets and destroys the abnormal electrical pathways in the heart that are responsible for SVT.
• Pacemaker: In rare cases, a pacemaker may be implanted to regulate the heartbeat, especially if other treatments are ineffective or if the heart rhythm is excessively slow after SVT episodes.

Your doctor will determine the best treatment approach based on the severity of symptoms and overall heart health.

Lifestyle Changes to Manage SVT

Caring for your heart plays a vital role in managing supraventricular tachycardia (SVT). Adopting healthy habits can help reduce the frequency and severity of episodes:

• Eat a heart-healthy diet – Prioritize fruits, vegetables, whole grains, and lean proteins.
• Stay hydrated – Dehydration can act as a trigger for SVT episodes.
• Exercise regularly – Engage in moderate physical activities like walking, swimming, or cycling.
• Avoid smoking and excessive alcohol consumption – Both can contribute to heart rhythm disturbances.
• Manage stress – Practices like meditation, yoga, and deep breathing can help regulate heart rate.
• Get enough sleep – Poor sleep quality has been linked to an increased risk of heart arrhythmias.

Why Sleep Matters: A study funded by the National Heart, Lung, and Blood Institute found that individuals with healthy sleep patterns had a 29% lower risk of developing atrial fibrillation, a common arrhythmia. While atrial fibrillation differs from SVT, both are supraventricular arrhythmias, suggesting that quality sleep may help protect against abnormal heart rhythms.

Continuous ECG Monitoring for Heart Health Management

Continuous ECG monitoring during various daily life activities plays a vital role in managing heart health, especially for individuals with SVT or other arrhythmias. By continuously tracking heart rhythms, wearable ECG monitors empower both patients and healthcare providers to detect irregularities early and make informed decisions about treatment and lifestyle adjustments.

The benefits of continuous ECG monitoring include:

• Early Detection of Irregular Heart Rhythms: Identifies changes in heart rate patterns before they become severe.
• Remote Monitoring by Healthcare Providers: Allows doctors to analyze heart activity without frequent clinic visits.
• Personalized Health Insights: Helps individuals understand their heart’s behavior, recognize triggers, and manage symptoms effectively.
• Peace of Mind: Enables continuous monitoring anytime, reducing anxiety and promoting a better quality of life.

With continuous ECG monitoring, individuals can take control of their heart health and live with greater confidence.

When to Seek Medical Attention

If you experience a sudden irregular heartbeat for the first time or if an episode lasts longer than a few seconds, consult your doctor. Seek emergency care if you have chest pain, difficulty breathing, or if your heart rate remains elevated for more than 30 minutes. You should also see your healthcare provider if you experience symptoms of SVT, including fatigue, dizziness, lightheadedness, passing out, palpitations (fluttering in your chest), or shortness of breath. Early evaluation can help determine the cause and appropriate treatment.

Final Thoughts

SVT is a condition characterized by a rapid heartbeat due to irregular electrical signals in the heart. Although it is typically not life-threatening, it can cause discomfort and may require lifestyle adjustments or medical treatment. If you suspect you have SVT, consult a healthcare professional for an accurate diagnosis and a personalized management plan. Additionally, leveraging continuous ECG technology for at-home monitoring can help track heart health and enhance overall well-being.

Disclaimer

This content is for informational purposes only and should not be considered medical advice. Always consult a healthcare professional for proper diagnosis and treatment.