Nonsustained ventricular tachycardia, a type of arrhythmia, can cause short episodes of rapid heart rate and related symptoms. It usually doesn’t affect life expectancy, but treatment can help you avoid complications.

Nonsustained ventricular tachycardia (NSVT) is a type of ventricular tachycardia (VT) that develops within your heart’s ventricles (lower chambers). Like other types of tachycardia, NSVT causes a rapid heart rate of more than 100 beats per minute (bpm) when you’re at rest.

As the name suggests, NSVT differs from other forms of VT because episodes may stop spontaneously. Despite this difference, NSVT and all types of VT, are serious medical conditions.

Learn more about this type of tachycardia, including its possible causes, treatment options, and overall outlook for people with NSVT.

NSVT may not cause noticeable symptoms because it lasts less than 30 seconds at a time, but some people may experience:

Nonsustained vs. sustained ventricular tachycardia

Both nonsustained and sustained VT cause at least 3 consecutive heartbeats, measuring more than 100 bpm at rest.

Sustained VT is more serious in the short term. Symptoms last at least 30 seconds and cause blood flow difficulties that require emergency medical attention. NSVT lasts less than 30 seconds and doesn’t cause reduced blood flow.

If your symptoms last for more than 30 seconds, seek emergency medical attention by calling 911 or local emergency services.

Ventricular tachycardia (VT) is caused by issues in your heart’s lower chambers, which lead to faulty signals and an abnormally high heart rate.

While it’s not clear why some people have nonsustained rather than sustained VT, the two subtypes share similar causes. The most common kind of VT is ischemic (coronary) artery disease.

VT may also be caused by other underlying issues with your heart, such as:

Other possible causes include electrolyte imbalances, illegal or nonprescribed use of medications or substances, and medication side effects.

NSVT is a relatively common type of heart arrhythmia, especially in older adults.

You may be at an increased risk of developing NSVT if you have:

To diagnose NSVT, a doctor will first need to determine the presence of VT. They can find VT with the following tests:

  • physical exam, during which a doctor will also measure your pulse and blood pressure
  • blood tests, including complete blood count and tests for electrolyte levels, such as:
    • potassium
    • calcium
    • magnesium
  • electrocardiogram (EKG) to measure your heart’s electrical activity and help a doctor identify any underlying issues, such as cardiomyopathy or long QT syndrome
  • echocardiogram, which uses ultrasound technology to provide pictures of your heart
  • invasive coronary angiogram, which uses X-rays and is typically used after cases of VT, cardiac arrest, and heart attacks

Once a doctor confirms VT, they can then figure out the type depending on the duration of your heart arrhythmia episodes and any effects on your blood flow. NSVT is diagnosed in cases of shorter episodes without blood flow effects.

Sometimes, NSVT may be an incidental finding during exercise stress tests or as an acute experience during outpatient treatment for heart failure, for example.

The goal of NSVT treatment is to help regulate your heart rate.

Medication options to control your heart rate include:

Healthcare professionals may administer these medications intravenously on a short-term basis.

Long-term treatment may involve implanting a pacemaker or implantable cardioverter defibrillator, especially if medications don’t work.

According to 2016 research, NSVT may increase the risk of complications, including stroke, heart failure, or death, especially in people who already have heart disease.

Advanced age and underlying chronic medical conditions, like kidney disease or diabetes, can also increase the risk of NSVT complications.

One 2021 study of 83 people with NSVT found that death was uncommon. More studies are needed to determine the overall outlook for people with NSVT, but researchers believe that idiopathic cases (without structural heart disease) and a lack of comorbidities may not affect the average life span.

How serious is nonsustained ventricular tachycardia?

Even though NSVT episodes don’t last as long as sustained VT or cause immediate difficulties with blood flow, NSVT is still a serious medical condition that requires treatment. Long-term treatment is also needed to prevent complications, such as cardiac arrest, stroke, or death.

Can stress cause nonsustained ventricular tachycardia?

Severe emotional stress is a known cause of tachycardia, which is why you might notice an increased heart rate when you experience stress, even at rest. Despite the connection to tachycardia, experts don’t consider stress to be a cause of NSVT.

Can I prevent nonsustained ventricular tachycardia?

Doctors typically diagnose NSVT as an incidental finding, but you may still be able to prevent NSVT if you have certain known risk factors for VT. This prevention may include medications to help control your heart rhythms.

NSVT is a common type of heart arrhythmia and a subtype of VT. While experts consider it a serious condition, the overall outlook for people with NSVT is generally favorable when it’s found early in people with lower risk factors for heart disease.

If you have a personal or family history of heart disease, you may consider talking with a doctor about NSVT. Because of the short duration of episodes, NSVT may not cause symptoms and can go undetected until a healthcare professional finds it during testing for other conditions.