How is paroxysmal supraventricular tachycardia (PSVT) treated?

PSVT episodes can be stopped in various ways. First, you can try a fairly simple approach known as the Valsalva maneuver:

The Valsalva maneuver involves using certain breathing techniques and body positions to increase the pressure in the chest and belly area. This stimulates the vagus nerve, which leads to the heart. The aim is to slow down the heart rate and make it return to normal. The Valsalva maneuver is quite easy to do and thought to be easy on your body too.

One way to do it involves closing your mouth, holding your nose, and trying to blow out or push down into your belly with all your strength – a bit like when trying to stop hiccups.

The following Valsalva maneuver approach has proven particularly effective: You lie on your back and raise your upper body slightly. Then you breathe out forcefully for about 15 seconds while lowering your body and raising your legs. When you breathe in after that, you lower your legs and raise your upper body again.

If this is done in a doctor’s practice or a hospital, they will help you to change positions and give you a tube to blow into.

The vagus nerve can be stimulated in a similar way by quickly drinking a glass of cold water or placing a very cold, wet towel on your face. Some doctors massage one side of your neck for 5 to 10 seconds to put pressure on the carotid artery in your neck. The aim is to stimulate the vagus nerve and slow down the heart rate that way. It is important to check whether your blood vessels are healthy before doing this. So the doctor will first examine your neck with the help of a stethoscope or an ultrasound scan.

If doing a Valsalva maneuver doesn’t help, medication called adenosine can reset the heart rhythm. In certain types of PSVT it can be used immediately too. Adenosine is injected into a vein. Possible side effects include chest pain and shortness of breath.

If that doesn’t help either, other medications can be used to influence your heart rate – beta blockers and calcium channel blockers in particular. They are injected during the PSVT episode and may cause side effects like a headache, dizziness and a drop in blood pressure.

In rare cases, PSVT can cause problems. The heart may beat so fast that each beat doesn’t have enough power to pump blood around the body. This causes serious blood circulation problems. Then a controlled electric shock is quickly given to restore the normal heart rhythm. This procedure is called electrical cardioversion.

Because the electric shock is painful, you’re given a brief, mild general anesthetic first. The cardioversion is done using a defibrillator, which sends the electric shock through two electrodes that are placed on the chest. This can result in redness or burns on the skin. The anesthetic may also lead to breathing problems, blood circulation problems, nausea and vomiting.

Even if the blood circulation is still stable, electrical cardioversion is sometimes performed – for instance, if nothing else has helped to restore a normal heart rate or if the medication isn’t well tolerated.

The most common treatment to prevent further episodes of PSVT is known as catheter ablation. This procedure involves inserting a thin tube ( catheter) into a vein in the groin and pushing it through to the heart. Then the surgeon destroys (ablates) the heart tissue that is causing the abnormal heartbeat. In most people, this gets rid of the problem for good.

The chances of success depend on the cause of the PSVT:

• If it’s caused by electrical signals circling around the AV node, about 20 to 50 out of 1,000 people develop PSVT again.
• If these “circling” signals are a result of additional electrical pathways between the upper and lower heart chambers, 63 to 99 out of 1,000 people get PSVT again.
• If the fast heart rate is caused by scar tissue in the upper heart chambers, up to 200 out of 1,000 people have episodes of PSVT again.

Although the procedure generally doesn’t cause any problems, there are some associated risks. These include bleeding, injury to the heart, and the development of other heart rhythm disorders such as a slow heartbeat (AV block). But complications like this are generally rare in people who have catheter ablation for the treatment of PSVT. Here, too, the risk depends on the cause of the PSVT:

• If it’s caused by electrical signals circling around the AV node, about 3 to 7 out of 1,000 people have complications. These complications are life-threatening in only 1 out of 1,000 people at the most.
• In the other (less common) types of PSVT, about 12 to 15 out of 1,000 people have complications – and 1 to 3 of them die as a result.

One option is to regularly take long-term medication to keep the heart rate normal and prevent PSVT episodes. Beta blockers and calcium channel blockers can be used for this purpose. If they don’t work, a different kind of heart medication (anti-arrhythmics) can be used instead – but only in people with certain types of PSVT.

If none of these things help but treatment is urgently needed (for example, because the PSVT episodes are making the heart weak), doctors might recommend a procedure to destroy tissue in the AV node. After that, electrical signals coming from the upper heart chambers are no longer passed on to the lower chambers. So a pacemaker is implanted to keep the heart beating at a normal rate.

Catheter ablation is recommended if you often have PSVT episodes and they cause symptoms. If you only have rare episodes of PSVT that don’t bother you much, you don’t need this treatment. But it’s still important to discuss the options in depth with your doctor and go for regular check-ups.

Sometimes catheter ablation is also recommended for people who don’t have any symptoms – for example, if their PSVT is caused by an additional electrical pathway in their heart (pre-excitation syndrome). Then the doctor examines the heart first, in a procedure that allows them to take a close look at the additional pathway. That way, they can see whether the PSVT is likely to increase the risk of serious, potentially life-threatening complications. If it is, the additional electrical pathway is destroyed during that same procedure. So there’s no need for a second procedure. This is particularly recommended for athletes, as well as people who have a high level of responsibility for others or could end up in dangerous situations in their job – like airline pilots.

If you're deciding whether to have catheter ablation or another treatment for an abnormally fast heart rate, this decision aid can help you choose a suitable treatment together with your doctor.