Ventricular arrhythmia (VA) is an abnormal heart rhythm that begins in the ventricles, the heart’s two lower chambers. The rhythm may be too fast or too uncoordinated for the heart to function properly.

A ventricular arrhythmia is a serious medical problem and requires urgent treatment.

Diagnosing VA usually requires a monitor or electrocardiogram to record the changes in heart rhythms. Once a doctor evaluates the type of VA you are experiencing, they can suggest a treatment plan. This may involve a combination of medications, medical devices, or procedures to address the cause of the arrhythmia.

Your heart usually beats to a steady rhythm, with the ventricles (the heart’s lower two chambers) and the atria (the heart’s upper two chambers) working harmoniously. This keeps oxygen-rich blood pumping to all the organs and tissues in the body.

The heart’s left ventricle pumps blood through the aorta artery and out to the rest of the body. The right ventricle pumps blood to the lungs, where the blood exchanges carbon dioxide for oxygen before returning to the heart.

The coordinated contraction and relaxation of the heart’s chambers is controlled by the heart’s electrical system. If there is a disruption or problem with the electrical activity in the lower chambers, the result can be a ventricular arrhythmia.

A heart arrhythmia can develop anywhere in the heart and cause symptoms that range from mild to life threatening.

When you have VAs, the lower chambers of the heart beat out of sync and cannot fill with enough blood or expel enough blood out to the body.

Each VA type presents with different symptoms and can lead to unique complications if not properly treated. VA types include:

  • ventricular tachycardia (VT), an abnormally fast heart rhythm (more than 100 beats per minute) that starts in the ventricles. VT episodes may last a few seconds or several hours. Because the heart is beating so fast, the ventricles don’t have time to fully contract with each heartbeat, so less blood is pumped out to the body.
  • ventricular fibrillation (VFib), a condition in which the ventricles quiver, rather than contract and relax in their usual steady, robust pattern. VFib also interferes with the heart’s ability to pump enough blood to meet the body’s demands.
  • Torsades de pointes, which occurs in people with long QT syndrome. The QT interval is the time needed for an electrical signal to activate the ventricles and then recharge. Having long QT syndrome means that the recharging time (which is the vulnerable period) is abnormally long. Sometimes, this may result in rapid or irregular heartbeats, but this isn’t always the case. Torsades de pointes (which means “twisting of the points” in French) means the ventricles are beating too fast and are out of sync with the atria. The cells are also out of sync with each other.
  • premature ventricular contraction, a single beat produced in the lower heart chambers. They may not signal a serious incident, but if they occur too often, they may increase your risk of VAs.

The symptoms of VA are similar to those of other types of arrhythmias. In a mild case, you may not be aware of a change in your heart rhythm. If you experience symptoms, these may include:

  • racing heart
  • fluttering heartbeats
  • chest pain
  • lightheadedness
  • fainting
  • sweating
  • shortness of breath

Diagnosing VAs usually requires an electrocardiogram (ECG) to measure the electrical activity in the heart. Other tests and tools are used to make a final diagnosis. These may include:

  • a clinical review of symptoms, including when they started and how long they last
  • an overall medical history, focusing on factors that may contribute to heart problems
  • a physical exam, in which a healthcare professional listens to your heart, checks your pulse, and looks for swelling in your lower limbs, which could indicate heart failure or an enlarged heart
  • blood tests to check your levels of electrolytes, which affect heart function
  • Holter or event monitors, which are wearable devices that can detect changes in your heart rhythm over a period of days
  • echocardiogram, which uses sound waves to create live, moving images of your heart

The treatment for VA depends on several factors, particularly the type of arrhythmia, as well as your age and overall health. VA may need immediate treatment for acute symptoms, but it may also require long-term care for chronic symptoms.

The three most common types of treatments are:

Antiarrhythmic drugs

Medications that act on the heart’s rhythm are sometimes used alone but may also be prescribed as add-on therapies.

Medications to treat VAs include:

  • ranolazine (Ranexa)
  • amiodarone (Pacerone, Nexterone)
  • sotalol (Betapace)
  • lidocaine/mexiletine

Although not antiarrhythmic drugs, doctors may also use beta blockers to reduce heart irritability and slow heart rate.

A 2018 study found that the drug ranolazine can be effective in reducing the number of VAs in people with a variety of cardiac conditions, including long QT syndrome.

Other research also suggests that amiodarone is effective but poorly tolerated by many people with VAs, while sotalol is generally well tolerated but may have limited effectiveness.

Medications may be used to stop a severe episode of VA, and medications may also be used for long-term management.

Implantable cardioverter defibrillator (ICD)

An implantable cardioverter defibrillator (ICD) is a small device placed in the chest to detect abnormal rhythms and send an electrical shock to the heart to restore a normal rhythm. It is the primary treatment for people with VA.

ICDs are effective and can be lifesaving.

In cases of ventricular tachycardia or fibrillation — both medical emergencies — a doctor may need to send a shock to the heart. This is typically achieved with an external device, but if you have an ICD, it can be used for this purpose.

Catheter ablation

Using a special catheter threaded through a blood vessel starting in the forearm or upper leg, a doctor can deaden tiny clusters of cells in the heart that are triggering the arrhythmia. The tip of the catheter is fitted with a device that uses radio waves (radiofrequency ablation) or extreme cold (cryoablation) to destroy the affected heart tissue.

A 2018 study notes that while catheter ablation is a primary treatment option for VT, the doctor’s experience performing the ablation is an important consideration, as the procedure is not without risks.

Age a contributing factor for VAs and other heart problems. The wear and tear on the heart through the years can affect the electrical system, valves, and other components of the heart.

Other possible factors include:

Treating VA promptly and thoroughly is critical to avoid complications. Untreated VAs may lead to:

  • lightheadedness
  • fainting
  • heart failure
  • damage to the heart muscle
  • kidney problems and other organ trouble
  • sudden life threatening cardiac arrest

Treated VAs don’t have a significant effect on life expectancy and quality of life. Successful ablation can sometimes eliminate arrhythmias permanently, though the abnormal rhythms may return for some people. At that point, you may need to consider getting an ICD or having a second ablation if a doctor believes that would be effective.

Ventricular arrhythmia is a serious health condition in which abnormal heart rhythms originate in the heart’s lower chambers and affect the way the entire heart functions.

If you notice symptoms, such as a racing or fluttering heart rate or feeling faint, consider seeking prompt medical care.