Paroxysmal Supraventricular Tachycardia (PSVT)

PSVT stands for paroxysmal supraventricular tachycardia. There are multiple types of this arrhythmia, or abnormal heartbeat, but they all start in the upper part of your heart. You have episodes where your heart beats very fast. These episodes start and end abruptly. Each episode may last for just a few seconds, several minutes or many hours.

You don’t always need treatment, and the condition usually isn’t life-threatening. If needed, providers can treat PSVT with medicines or procedures.

When you’re learning about PSVT, it can help to know what each part of the name means:

• Paroxysmal: Starting and ending abruptly
• Supraventricular: Above the ventricles (your heart’s lower chambers)
• Tachycardia: Fast heartbeat

PSVT is defined by its “paroxysms,” or abrupt episodes.

This condition affects about 168 to 332 out of every 100,000 people in the U.S. It’s diagnosed in people of all ages.

Types of this condition

There are a variety of arrhythmias that healthcare providers would consider PSVT. The most common ones include:

• AV nodal reentrant tachycardia (AVNRT): This fast heartbeat happens when some electrical signals go around in circles in your AV node. Normally, they should pass through the node and continue to your lower heart chambers.
• AV reentrant tachycardia (AVRT): In this case, electrical signals take an extra pathway that lets them reach your lower chambers too soon. This can make your heart beat too fast. AVRT is a feature of Wolff-Parkinson-White syndrome.
• Focal atrial tachycardia: Electrical signals start in the wrong area of your atria (upper chambers).

Symptoms of PSVT

PSVT is an episode where your heart beats very fast — over 100 beats per minute (bpm). Your heart rate may even reach 200 bpm or higher. The faster your heart rate, the more likely you are to have other symptoms, like:

• Heart palpitations (the feeling that your heart is racing, pounding or flip-flopping)
• Chest discomfort
• Shortness of breath
• Dizziness or lightheadedness
• Fainting

These symptoms may stop on their own. In some cases, you may need treatment to stop an episode.

PSVT causes

Abnormal electrical activity in your heart causes PSVT. This usually means electrical signals are doing one of the following:

• Taking an extra pathway from your top to bottom heart chambers
• Going around in circles in your AV node (a small area of tissue that helps signals reach your bottom chambers) or your upper chambers (atria)
• Starting from the wrong spot in the top chambers

Triggers

These electrical issues won’t cause symptoms all the time. Instead, you’ll have episodes that come and go. What triggers an episode can vary from person to person, but may include:

• Stress or anxiety
• Caffeine
• Alcohol
• Smoking
• Physical activity
• Lack of sleep
• Dehydration
• Electrolyte imbalances

Sometimes, there’s no clear trigger.

Certain medications can rarely increase your risk, particularly if they cause changes to your electrolytes, hormones, such as thyroid, or adrenaline. Check with your provider if any of your medications need to be adjusted.

Complications of this condition

PSVT can damage your heart if it happens often, leading to dilated cardiomyopathy. When this happens, healthcare providers call it “arrhythmia-induced cardiomyopathy.” The good news is that treating the arrhythmia can often reverse some or all of the damage.

How doctors diagnose PSVT

Your healthcare provider will perform a physical exam and ask you some questions. You’ll talk about:

• Your medical history
• Any symptoms you’re having
• When the fast heartbeat episodes start
• How long they last

Tests that check your heart’s electrical activity are key to making a PSVT diagnosis. For example, an EKG in your provider’s office is often the starting point. This can be very helpful. But it may not capture the fast heartbeat as it’s happening.

That’s why your provider may suggest ambulatory monitoring. This means you wear a device as you go about your daily life. It saves data for your provider to review and often reveals things that an EKG didn’t.

Other tests you may need include:

• Blood tests
• Echocardiogram
• CT angiogram
• Stress test

How is PSVT treated?

Not everyone with PSVT needs treatment. But your provider may recommend treatment in certain situations — like if an episode doesn’t go away on its own, or if you have frequent or severe symptoms.

Treatments to stop an episode when it’s happening (acute therapy) include:

• Vagal maneuvers: These are physical actions, like breathing or moving in certain ways, that can slow your heart rate. Your provider may try these first if you’re stable (meaning enough blood is flowing to your body). Never try these on your own unless your provider says to.
• Medicine: Your provider can give you medicine through an IV or orally if vagal maneuvers don’t work or aren’t an option for you. Commonly used medicines to treat PSVT episodes include adenosine, verapamil and diltiazem.
• Electrical cardioversion: You may need this procedure if other treatments don’t work or you’re unstable (not enough blood flow to your body). Your provider uses a device to send electrical currents to your heart. This returns your heart rate to a normal rhythm and rate.

Acute therapy may be all you need. But if PSVT disrupts your life or puts you at risk of heart problems, you may need catheter ablation. This procedure creates helpful scar tissue in your heart to block abnormal signals. Ablation is safe and highly successful for most people and, depending on the type of PSVT, can frequently cure it.

In certain situations, providers recommend taking medicine long-term instead of ablation. They may prescribe beta-blockers or calcium channel blockers for you to take. You may take your medicine all the time or only as needed (the “pill-in-the-pocket” approach). You’ll work with your provider to decide the best plan to meet your needs.

When should I see my healthcare provider?

Talk to your provider if you have any concerns about your heartbeat or any symptoms of PSVT. If you have PSVT, you’ll see your heart doctor for routine checkups and tests.

Seek medical care right away if:

• An episode doesn’t go away on its own
• You have chest pain or discomfort
• You faint or feel like you might

What can I expect if I have this condition?

Your prognosis depends on the treatments you receive and whether you have other heart problems. Ablation could cure your PSVT so you won’t have to deal with symptoms anymore. Symptoms are more likely to come back at least once a month if you take medicines but don’t do ablation.