What is paroxysmal supraventricular tachycardia?

Paroxysmal supraventricular tachycardia (PSVT) is a very fast heartbeat that comes and goes.

What is the cause?

An electrical signal in your heart starts each heartbeat, causing the heart muscle to squeeze (contract). Normally, this signal starts in the upper right chamber of the heart (the right atrium) at a place called the sinus node. The signal then follows normal pathways to the upper left atrium and to the lower chambers of the heart (the ventricles). Sometimes the electrical signals don’t follow the normal pathways. This may make the heart beat very fast.

There are several types of PSVT. The most common type happens to adults in their 20s and 30s. It’s more common in women than men. It may happen more often during pregnancy. People with this type of PSVT almost always have an extra electrical pathway connecting the upper and lower chambers. When the electrical signal goes down both pathways at the same time, the heart beats normally. If the electrical signal goes down one pathway faster than the other, it can then go back up the extra pathway, making the heart beat very fast.

Other causes of PSVT include heart disease, heart infections, health problems such as lung disease or an overactive thyroid gland, alcohol or drug abuse, caffeine, or smoking.

What are the symptoms?

Symptoms of PSVT may be mild or severe. Symptoms may include:

• Feeling like the heart is beating too fast or too hard or skipping beats or fluttering
• Feeling weak, dizzy, or lightheaded
• Fainting
• Shortness of breath
• Chest tightness

How is it diagnosed?

Your healthcare provider will ask about your symptoms and medical history and examine you. Tests may include:

• An ECG (also called an EKG), which measures and records your heartbeat. You may have an ECG while you are resting or while you exercise on a treadmill. You may also be asked to wear a small portable ECG monitor for a few days or sometimes a couple of weeks.
• Blood tests
• Chest X-ray
• An electrophysiologic study (EPS), which uses tiny wires put into your heart through your veins to look at the electrical pathways in your heart

How is it treated?

The goal of treatment is to help the heart keep a normal rhythm. Your treatment depends on the cause of the PSVT, how often you have symptoms, and the severity of your symptoms.

You may not need treatment if the attacks are rare, don’t last long, and don’t cause serious symptoms. For most people, PSVT starts suddenly and lasts just a short time. The heart goes back to a normal rhythm on its own. If you keep having spells of PSVT, treatment may help keep you from having so many spells.

Your healthcare provider can show you ways to stop a spell of PSVT. Other possible treatments are:

• Medicine to control the heart rate
• Electrical cardioversion: First, you will be given medicine called anesthesia to keep you from feeling pain during the procedure. Then your chest will be given an electrical shock. The electrical shock should make your heart start beating normally again. You may need medicine to keep your heart rhythm normal after this procedure.
• Ablation: Ablation is a procedure that uses a small tube called a catheter to deliver energy to the inside of the heart. The energy (usually radio waves) scars small areas of heart tissue. The scars block abnormal electrical pathways and help you have a normal heart rhythm. With some types of ablation treatment, you will also need a pacemaker. A pacemaker is an electronic device put under the skin of your chest to help control the heartbeat.

How can I take care of myself?

Follow full course of treatment prescribed by your healthcare provider. Ask your provider:

• How and when you will hear your test results
• How long it will take to recover
• What activities you should avoid and when you can return to your normal activities
• How to take care of yourself at home
• What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup.

How can I help prevent PSVT?

The best prevention is to have a heart-healthy lifestyle.

• Keep a healthy weight.
• Eat a healthy diet.
• Stay fit with the right kind of exercise for you.
• Decrease stress.
• Don’t smoke.
• Limit your use of alcohol.

If you have heart disease or high blood pressure, follow your healthcare provider’s instructions for treatment.