What is non-sustained ventricular tachycardia (NSVT)? (2023)

Non-sustained ventricular tachycardia(NSVT, or non-sustained ventricular tachycardia) is an abnormal heart rhythm that begins in the ventricles, which are thelower chambers of the heart. It occurs as three or more consecutive heartbeats at a rate of more than 100 beats per minute and lasts less than 30 seconds.

Because it does not persist, NSVT is not considered as dangerous as sustained ventricular tachycardia (SVT), which lasts longer than 30 seconds. In fact, while not true for everyone, non-sustained VT may be completely harmless in some people.

This article discusses the possible symptoms and causes of NSVT, as well as how it is diagnosed. You will also learn how this type ofabnormal heart rhythm(or arrhythmia) is treated and when you should seek medical attention.

Signs and symptoms of NSVT

NSVT is defined as an episode of ventricular tachycardia that:

• It involves a heart rate of more than 100 beats per minute.
• Persists for at least three heartbeats
• Lasts less than 30 seconds

Most of the time, NSVT does not cause any symptoms. If this happens,palpitations— when you feel a fast or irregular heartbeat — it may be the only one. Palpitations may be associated with shortness of breath or chest pain.

Occasionally, NSVT can causedizzinessIdizziness. Rarely, loss of consciousness (syncope) can occur.

When to seek medical attention

Although NSVT may be harmless, it can also be a marker for the development of sustained ventricular arrhythmias and sudden death.

It is important that you see your doctor if you are experiencing:

• transient chest pain
• dizziness
• Your heart races even if you come and go

Call 911 or seek emergency care if you experience:

• Breathing problems
• Chest pain that lasts more than a few minutes
• Chest pain accompanied by other symptoms such as nausea, dizziness, and/or cold sweats
  

Causes of NSVT

NSVT may be caused by a previously unknown structural heart disease, that is, a condition that alters the anatomy of the heart.

It can also result from electrical instability within the heart that can eventually lead to even more dangerous arrhythmias such asventricular fibrillation.This is when the heart stops beating as it should and starts to flutter, causing cardiac arrest.

There are also reversible factors that can contribute to the development of PVC.

structural heart disease

The types of heart disease most commonly associated with NSVT are:

• Coronary artery disease (CAD):When the blood vessels supplying the heart become narrowed or blocked, which can lead to aheart attack
• Heart failure due to dilated cardiomyopathy:When the chambers of your heart become too large and cannot pump blood properly

NSVT is also seen with:

• Hypertrophic cardiomyopathy:When you have an abnormally thick heart muscle
• heart valve disease(especiallyaortic stenosismimitral regurgitation):When one or more of the four heart valves malfunction

electrical instability

Sometimes NSVT is caused by an electrical problem in the heart rather than a structural problem.

The most common of these conditions isrepetitive monomorphic ventricular tachycardia (RMVT).

RMVT is a disorder that almost only occurs in young to middle-aged people without structural heart disease.

Common symptoms include palpitations and dizziness. In this disorder, an episode of NSVT tends to be triggered by emotional stress or exercise.

reversible factors

Several reversible factors can trigger NSVT, such as:

• Electrolyte imbalances (eg.low potassiumolow magnesiumblood levels)
• Substance use, including cocaine and methamphetamine use
• Low level of oxygen in the bloodstream (hypoxia)
  
• A low number of healthy red blood cells in the bloodstream (anemia)
• Certain non-cardiac conditions, such asthyroid disease
  

How is it diagnosed?

Because NSVT does not usually cause alarming symptoms, it is usually discovered during aelectrocardiograma (ECG)done for another reason. If a person experiences symptoms, NSVT can be diagnosed through aambulatory ECG monitoring system.

heart rate monitoring

Ambulatory ECG systems record your heart's electrical activity over days, weeks, or even years. This longer monitoring period makes it possible to detect and record cardiac arrhythmias that can come and go, such as NSVT.

Acardiologist— a doctor who treats heart conditions — reviews records from the ambulatory ECG system for NSVT or other arrhythmias.

AMonitor HolterIt is a kind of ambulatory ECG system. This lightweight, portable monitor is connected by wires to small discs called electrodes that are attached to your chest. The Holter monitor is worn for 24 to 48 hours or longer and records your heart rate continuously.

additional exams

If NSVT is diagnosed, your doctor will perform further tests to determine if any reversible factors are present. For example, in addition to a medical history/physical exam, various blood tests, such as abasic metabolic panel, complete blood count,othyroid stimulating hormone (TSH)can be ordered.

Your doctor will also want to determine if there is any underlying heart disease.

Tests that may be done to check for heart disease include:

• stress test
• echocardiography
• Cardiac Magnetic Resonance Imaging (MRI)
• coronary angiography

If the results of one or more of these tests show the presence of underlying heart disease, such as coronary artery disease, treatment will be directed toward that diagnosis.

If no underlying heart disease is found, people may be referred to a heart rhythm specialist called a cardiac electrophysiologist to evaluate MRTV and other conditions that can cause this arrhythmia.

non-sustained VT vs. sustained television

During the diagnostic process, your doctor will determine if you have NSVT or SVT. The duration of the arrhythmia is a telling differentiator.

DVT treatment

Treatment of NSVT depends on the underlying cause of the arrhythmia and the presence of symptoms.

If there are no symptoms and there is no underlying heart disease, no treatment may be necessary, apart from regular follow-up with a health professional.

NSVT in people with healthy hearts is generally considered harmless.

Medicines

For those with NSVT symptoms,beta blockers,calcium channel blockers, o Pacerone (amiodarone) It can be used.Amiodarone is aantiarrhythmic drug— a medicine that works to keep your heart in a regular rhythm.

Tambocor (flecainide) and Betapace (sotalol) are also antiarrhythmic drugs, but they are not generally recommended to treat NSVT.This is especially true if the NSVT occurs as a result of a heart attack.

However, these and other antiarrhythmic drugs may be used in certain cases when someone has severe symptoms and is under the care of an electrophysiologist.

ablation therapy

For people with severe symptoms or who cannot tolerate or receive no benefit from antiarrhythmic drugs,ablation therapyIt can be used.

This therapy involves the use of heat or cold energy to destroy the part of the heart thought to be the source of the abnormal electrical signals.

Ablation therapy is successful in treating NSVT approximately 80% of the time.

Deployable cardioverter-defibrillator

NSVT carries an increased risk of cardiac arrest and sudden death if it occurs along with coronary artery disease or heart failure. This is especially true for people withHypertrophic cardiomyopathy.

With these conditions, the risk is more related to reduced left ventricular blood flow (calledejection fraction) than the presence of the NSVT itself.

To reduce the risk, aDeployable cardioverter-defibrillator(CID) may be recommended in certain people.

An ICD is a battery-operated device that is placed under the skin of your breast. It monitors the rhythm of your heart and delivers mild electrical currents or shocks if the rhythm becomes abnormal.

Prevention

NSVT cannot be directly prevented, but some heart conditions that cause it can be.

To optimize the health of your heart, it is important to do the following:

• Participate in at least 150 minutes a week ofmoderate intensity physical activity(for example, brisk walking) or 75 minutes a week ofvigorous intensity physical activity(for example, running).
• Eat a diet rich in fruits, vegetables, nuts, whole grains, lean protein, and fish.
• Minimize intake ofTrans fat, Red meat,processed meats,refined carbohydrates(for example, pasta and white rice) and sugary drinks.
• Lose weight if you are overweight or obese.
• Avoid tobacco use and exposure to secondhand smoke.

It is also important to see your doctor for regular checkups. These appointments are, among other things, to monitor youhypertension,high cholesterol, miType 2 diabetes, all of which can contribute to the development of heart disease.

Summary

Ventricular tachycardia is an abnormally fast heartbeat caused by irregular electrical impulses originating in the lower chambers of the heart. Nonsustained ventricular tachycardia is a type that stops on its own within 30 seconds.

NSVT can arise in healthy people or people with significant heart disease. Diagnosis involves the use of tests or monitoring of the heart rhythm. Other tests may be ordered to help find the cause of the ventricular tachycardia.

Treatment may not be necessary if there are no symptoms. But some with NSVT will need to treat any underlying heart conditions and/or relieve severe symptoms. NSVT is usually harmless, but it can develop into a more dangerous ventricular arrhythmia and cause sudden death.

A word from Verywell

While being diagnosed with NSVT can understandably cause anxiety, remember that this arrhythmia is common and can occur in healthy people. In other words, while it can be a sign of heart disease, it isn't always.

If you or a loved one is diagnosed with NSVT, see a cardiologist for a careful and detailed evaluation of the heart. You can then move forward with a personalized treatment plan based on the presence or absence of symptoms or any heart problems.