Ventricular tachycardia, or V-tach (VT), and supraventricular tachycardia (SVT) are two types of tachycardia. The term “tachycardia” refers to a heart rate of more than 100 beats per minute.

The key difference between VT and SVT is the source of the tachycardia.

In VT, tachycardia stems from the heart’s lower chambers, called the ventricles. In SVT, it stems from the heart’s upper chambers, called the atria.

Another key difference between the two is that VT is often life threatening, whereas SVT is rarely serious.

This article begins with an overview of how the heart works and goes on to describe the difference between VT and SVT, including differences in their symptoms, causes, diagnosis, and treatment. It also explains the outlook for each condition.

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To understand the differences between ventricular tachycardia (VT) and supraventricular tachycardia (SVT), it is first necessary to understand how the heart functions.

The heart has four chambers: two upper chambers called atria and two lower chambers called ventricles.

The right atrium receives oxygen-poor blood from the body and pumps it into the right ventricle. The right ventricle pumps the oxygen-poor blood to the lungs for oxygenation.

The left atrium receives oxygenated blood that is returning from the lungs and pumps it into the left ventricle. The left ventricle pumps the oxygenated blood to the rest of the body.

Medical professionals classify VT and SVT as an abnormal heart rhythm, or arrhythmia.

Both VT and SVT are forms of tachycardia. This is the medical term for a heart rate of more than 100 beats per minute.

The key difference between VT and SVT is the source of the arrhythmia. VT develops in the heart’s ventricles. SVT develops in the heart’s atria.


VT involves rapid ventricular contractions when the heart beats three or more consecutive beats at a rate of more than 100 beats per minute.

There are two types of VT:

  • Sustained VT: The heart beats rapidly for more than 30 seconds. This type of VT can lead to insufficient blood flow to the body. It can cause cardiac arrest and requires immediate medical intervention.
  • Non-sustained VT: The heart beats rapidly for fewer than 30 seconds. The episode does not lead to insufficient blood flow to the body. This type of VT tends to be more benign and less likely to need urgent medical intervention.

The symptoms of VT may vary depending on the cause. However, some common symptoms include:

  • heart palpitations
  • chest pain
  • shortness of breath
  • fainting
  • dizziness or lightheadedness

Depending on the cause of VT, the condition may cause cardiac arrest and even death. For this reason, anyone who experiences symptoms of VT should seek emergency medical attention.


SVT is a heart rhythm of more than 100 beats per minute. It begins in the heart’s atria.

Symptoms of SVT may include:

  • heart palpitations
  • chest pain
  • shortness of breath
  • dizziness
  • lightheadedness
  • loss of consciousness

Occasionally, SVT may not cause any symptoms. A person may not know it is happening.

A person who experiences symptoms of SVT should seek immediate medical attention. However, the condition is generally not serious or life threatening.

Below are some potential causes of VT and SVT.

VT causes

The most common cause of VT is ischemic heart disease. Ischemic heart disease refers to the weakening of the heart muscle due to impaired blood flow to the heart. In most cases, ischemic heart disease is the result of the narrowing of the blood vessels that supply the heart.

Other potential causes of VT include:

  • cardiomyopathies, which are disorders of the heart muscle
  • structural heart disease, which are abnormalities or defects in the heart or the arteries that transport blood from the heart
  • certain inherited heart conditions
  • electrolyte imbalances, such as:
    • hypokalemia (low potassium levels)
    • hypocalcemia (low levels of calcium)
    • hypomagnesemia (low levels of magnesium)
  • substance use
  • digitalis toxicity from a heart medication called digoxin

SVT causes

SVT occurs due to a fault with the electrical system that controls the heart. The condition is not usually serious, though some people may require treatment.

The following may act as SVT triggers in people who are susceptible to this type of arrhythmia:

  • medications
  • caffeine
  • alcohol
  • cigarette smoking
  • physical or emotional stress

Congenital heart disease also increases the risk of SVT. It is the most common type of symptomatic arrhythmia in infants and children.

Below are the diagnostic procedures for VT and SVT.

VT diagnosis

When diagnosing VT, a doctor may conduct the following:

  • a medical history assessing the person’s underlying risk factors for VT
  • a history of the person’s symptoms before and during the VT episode
  • a family history of any inherited cardiac conditions
  • an electrocardiogram (EKG) to assess the heart’s rhythm
  • noninvasive imaging tests to assess heart structure and function, such as:
    • echocardiogram
    • CT scan
    • heart MRI
  • a coronary angiogram to evaluate suspected coronary artery disease
  • genetic testing for people with a family history of heart disease

SVT diagnosis

An EKG can diagnose SVT. A doctor may also recommend other ways to monitor a person’s heart rhythm, including:

  • An ambulatory Holter monitor: This device is for people who experience frequent SVT episodes. The device attaches to a strap that a person wears around the neck, shoulder, or waist. Electrodes on the surface of the device record the heart’s rhythm continuously over 24–48 hours.
  • Cardiac event monitor: This device is for people who experience infrequent SVT episodes. The device attaches to a person’s wrist and features a button the person can press to record their heart rhythm when symptoms occur.
  • Loop monitor: This device is for people who experience very brief arrhythmias or symptoms that would prevent them from using a cardiac event monitor.

The treatment approaches for VT and SVT are outlined below.

VT treatment

Sustained VT can result in cardiac arrest. This is a potentially fatal condition involving an abrupt loss of heart function. Individuals who go into cardiac arrest require emergency resuscitation and life support.

People who do not go into cardiac arrest but lack sufficient blood flow require immediate defibrillation. This procedure involves using a device called a defibrillator to deliver an electric current to the heart to restore a normal heart rhythm.

In some cases, people may experience three or more episodes of sustained VT within 24 hours. Doctors may refer to this as a “VT storm.”

Treatments for a VT storm may include:

  • intravenous (IV) antiarrhythmic drugs
  • IV beta-blockers
  • defibrillation

Long-term therapies may also be necessary to help manage VT or prevent its recurrence. Examples include:

  • medications to stabilize heart rhythm
  • an implantable cardioverter defibrillator (ICD), which is a device that continuously monitors heart rate and delivers an electric shock to normalize heart rhythm when necessary
  • catheter ablation, which is a procedure that involves destroying a small section of the heart that is causing the VT

SVT treatment

People who experience long episodes of SVT may require treatment.

A healthcare professional may first try performing vagal maneuvers. These techniques stimulate the vagus nerve to treat arrhythmias. Examples include the:

Other treatment options may include medications and cardioversion. Cardioversion is a small electric shock to help the heart resume normal rhythm.

Catheter ablation is another option. It involves placing tubes through a vein or artery into the heart to identify where the arrhythmia is coming from.

Once the doctor identifies where the arrhythmia is coming from, they destroy the area of the heart muscle using heat. This is called a radiofrequency ablation.

The outlooks for VT and SVT are outlined below.

VT outlook

The outlook for people with VT depends on the underlying cause and whether the person has structural heart disease.

Idiopathic VT is VT that occurs without a known cause. This type carries a favorable outlook. Life expectancies almost match those of people without the condition.

Ischemic cardiomyopathy-induced VT (IC-VT) carries a poor outlook. Ischemic cardiomyopathy is heart damage resulting from insufficient blood flow to the heart. Without treatment, IC-VT may cause death within 2 years in up to 30% of cases. However, placing an ICD significantly improves survival rates.

SVT outlook

People who experience infrequent episodes of SVT lasting only a few minutes may not require treatment.

For some people, the following lifestyle strategies may help reduce SVT episodes:

  • avoiding or limiting caffeine and alcohol intake
  • not smoking
  • getting sufficient rest
  • performing vagal maneuvers

Some people may require medications to manage their SVT. If medications don’t work, radiofrequency ablation has a high success rate.

Is VT or SVT worse?

Of the two conditions, VT is typically more life threatening than SVT.

Aside from idiopathic VT, which generally carries a favorable outlook, other forms of VT can lead to cardiac arrest and even death.

In contrast, SVT is rarely life threatening. In many cases, it does not require treatment.

Ventricular tachycardia (VT) and supraventricular tachycardia (SVT) are heart arrhythmias that involve a heart rate of more than 100 beats per minute. In VT, the ventricles are the source of the tachycardia. In SVT, the atria are the source.

Of the two types of rapid heart rate, VT is the most serious. Without immediate treatment, it can cause cardiac arrest and even death. By contrast, SVT is rarely serious. Many cases resolve without treatment.

Since both types of tachycardia cause many of the same symptoms, anyone who experiences symptoms should seek immediate medical attention. If VT is the underlying cause, emergency medical treatment may be critical to survival.