Ventricular tachycardia is a heart rhythm disorder (arrhythmia) caused by abnormal electrical signals in the lower chambers of the heart (ventricles). This condition may also be called V-tach or VT.
A healthy heart normally beats about 60 to 100 times a minute at rest. In ventricular tachycardia, the heart beats faster than normal, usually 100 or more beats a minute.
The chaotic heartbeats prevent the heart chambers from properly filling with blood. As a result, your heart may not be able to pump enough blood to your body and lungs.
Ventricular tachycardia may last for only a few seconds, or it can last for much longer. You may feel dizzy or short of breath, or have chest pain. Sometimes, ventricular tachycardia can cause your heart to stop (sudden cardiac arrest), which is a life-threatening medical emergency.
Brief episodes of ventricular tachycardia may not cause any symptoms in some people. Or you may have:
- Shortness of breath
- Feeling as if your heart is racing (palpitations)
- Chest pain (angina)
Sustained and more-serious episodes of ventricular tachycardia may cause:
- Loss of consciousness or fainting
- Cardiac arrest (sudden death)
When to see a doctor
Many different conditions can cause ventricular tachycardia. It's important to get a prompt, accurate diagnosis and appropriate care. See your doctor if you or your child has any problems with the heartbeat. In some cases, urgent care is needed.
Get emergency care, or call 911 or your local emergency number for anyone experiencing these symptoms:
- Chest pain that lasts more than a few minutes
- Difficulty breathing
Ventricular tachycardia is caused by a disruption in the normal electrical impulses that control the rate of your heart's pumping action.
Many things can cause or contribute to problems with the heart's electrical system. These include:
- Abnormalities of the heart that result in scarring of heart tissue (sometimes called "structural heart disease"), the most common cause is a prior heart attack
- Poor blood flow to the heart muscle due to coronary artery disease
- Congenital heart conditions, including long QT syndrome
- Imbalance of electrolytes necessary for conducting electrical impulses
- Medication side effects
- Use of drugs such as cocaine or methamphetamine
In some cases, the exact cause of ventricular tachycardia can't be determined (idiopathic ventricular tachycardia).
The heart's electrical system
To understand the causes of heart rate or rhythm problems such as tachycardia, it helps to understand how the heart's electrical system works.
Your heart is made up of four chambers — two upper chambers (atria) and two lower chambers (ventricles). Your heartbeat is normally controlled by a natural pacemaker called the sinus node, which is located in the right atrium. The sinus node produces electrical impulses that normally start each heartbeat.
From the sinus node, electrical impulses travel across the atria, causing the atrial muscles to contract and pump blood into the lower chambers of the heart (ventricles).
The electrical impulses then arrive at a cluster of cells called the atrioventricular (AV) node — usually the only pathway for signals to travel from the atria to the ventricles.
The AV node slows down the electrical signal before sending it to the ventricles. This slight delay allows the ventricles to fill with blood. When electrical impulses reach the muscles of the ventricles, they contract, causing them to pump blood either to the lungs or to the rest of the body.
When anything disrupts this complex system, it can cause the heart to beat too fast (tachycardia), too slow (bradycardia) or with an irregular rhythm.
Any condition that puts a strain on the heart or damages heart tissue can increase your risk of ventricular tachycardia. Lifestyle changes or medical treatment may decrease the risk associated with the following factors:
- Heart disease
- Medication side effects
- Severe electrolyte imbalances
- Use of stimulant drugs such as cocaine or methamphetamine
If you have a family history of ventricular tachycardia or other heart rhythm disorders, you may have an increased risk of ventricular tachycardia.
Complications of ventricular tachycardia vary in severity and depend on how fast your heart is beating, how long the rapid heartbeat lasts, how often tachycardia occurs and your overall heart health. Possible complications include:
- Frequent fainting spells or unconsciousness
- Heart failure
- Sudden death caused by cardiac arrest
A dangerous condition related to ventricular tachycardia is ventricular fibrillation (V-fib). In V-fib, your lower heart chambers contract in a very rapid and uncoordinated manner.
This abnormal rhythm happens most often in people with heart disease or a prior heart attack. It may also occur due to electrolyte problems (such as high or low potassium levels) or, rarely, in otherwise normal hearts.
Ventricular fibrillation may also cause sudden cardiac arrest and lead to death if not treated immediately.
The best way to prevent ventricular tachycardia is to treat or eliminate risk factors that may lead to heart disease. If you already have heart disease, follow your treatment plan and a heart-healthy lifestyle.
Take the following steps:
- Exercise and eat a healthy diet. Live a heart-healthy lifestyle by exercising regularly and eating a healthy, low-fat diet that's rich in fruits, vegetables and whole grains.
- Maintain a healthy weight. Being overweight increases your risk of developing heart disease.
- Keep blood pressure and cholesterol levels under control. Make lifestyle changes and take medications as prescribed to correct high blood pressure (hypertension) or high cholesterol.
- Control stress. Avoid unnecessary stress and learn coping techniques to handle normal stress in a healthy way.
- Don't use recreational drugs. Don't use stimulants, such as cocaine. Talk to your doctor about an appropriate program for you if you need help ending recreational drug use.
- Go to scheduled checkups. Have regular physical exams and report any signs or symptoms to your doctor.
- Limit alcohol. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger. For some conditions it's recommended that you completely avoid alcohol. Ask your doctor for advice specific to your condition.
- Limit caffeine. If you drink caffeinated beverages, do so in moderation (no more than one to two beverages daily).
- Stop smoking. If you smoke and can't quit on your own, talk to your doctor about strategies or programs to help you break a smoking habit.
- Use over-the-counter medications with caution. Some cold and cough medications contain stimulants that may trigger a rapid heartbeat. Ask your doctor which medications you need to avoid.