Ventricular tachycardia

In ventricular tachycardia, the rapid heartbeat can usually be felt as a fluttering or pounding sensation (palpitations) in the chest. Episodes that last only a few seconds usually cause mild symptoms or none at all.

If an episode lasts longer, it can lead to dizziness, weakness, shortness of breath and chest pain. All of these symptoms can make you feel anxious. It may also result in fainting (syncope), or even circulatory failure.

Ventricular tachycardia is usually the result of a heart condition that changes the electrical pathways in the heart. Heart valve diseases, heart failure and coronary artery disease (CAD) may do this, for example – especially if they lead to a heart attack. Heart attacks cause heart muscle tissue to die, resulting in scar tissue in the heart. When "normal" electrical signals arrive at this scar tissue, they may split into two or more signals that then circle around the lower heart chambers. This makes the heart beat too fast.

Other possible causes of ventricular tachycardia include electrolyte imbalances, drug abuse, and overdoses of some medicines.

Children and young adults very rarely have supraventricular tachycardia. Then the cause is often a disease affecting the heart muscle tissue (cardiomyopathy) or a genetic predisposition. Surgery for congenital heart defects can also lead to ventricular tachycardia in younger people.

Ventricular tachycardia usually develops in people who already have another heart condition, like CAD or heart failure. That is why it’s more common in older people.

It is almost impossible to predict when and how often episodes of ventricular tachycardia will happen.

The rapid heartbeat in ventricular tachycardia means that there's not enough time between each beat for the lower heart chambers to fill with blood. If this goes on for too long, not enough blood is pumped around the body. Then the brain gets too little oxygen, which can result in unconsciousness, falls and injuries.

The heart muscle itself needs oxygen too. If it doesn't get enough oxygen-carrying blood during an episode, the heart muscle may become damaged. This may result in an acute life-threatening situation.

If ventricular tachycardia turns into ventricular fibrillation, the heart muscle quivers uselessly and can no longer pump any blood. Without treatment, this can lead to sudden cardiac death. If the person is not resuscitated quickly, they will die.

It can be difficult to diagnose ventricular tachycardia because you may not have an episode while you’re in a doctor’s practice or hospital – or an episode may have stopped on its own by the time you get there.

The fast heartbeat can be detected by measuring your pulse during an episode. Any symptoms or other medical conditions you have can also provide helpful information. Doctors can find out whether the fast heartbeat is actually ventricular tachycardia by doing an electrocardiogram (ECG) – but only if you’re connected to an ECG machine during an episode.

If no episode occurs during the normal ECG, a portable continuous ECG machine (often called a Holter monitor) can be used. It can be worn around your neck and under your clothing, for example. The device is connected to electrodes that are placed on your chest from the outside. The monitor can then record your heartbeat for several days.

An ECG stress test (exercise ECG) may be done to see episodes that only occur during strenuous physical activity. Sometimes doctors will give you a medicine that increases your pulse as if you were doing exercise or stressed. That is another way to find out whether those kinds of situations trigger an abnormal heartbeat. The tests using medicine are done under the same close observation as the stress tests are.

Further testing is usually done to find the underlying cause of the ventricular tachycardia, such as a heart attack or congenital heart disease. The testing may include things like an ultrasound scan of the heart (echocardiogram), genetic tests, magnetic resonance imaging (MRI) or cardiac catheterization. This also allows doctors to take a closer look at the electrical pathways in your heart.

The risk of dying from ventricular tachycardia is particularly high in adults if heart disease is causing it. Apart from treating the causes, various procedures can be done to lower the risk of ventricular tachycardia episodes. These treatments are often combined.

• Implanting a defibrillator is commonly recommended. This device can detect ventricular tachycardia and quickly stop it by giving off controlled electric shocks.
• The heart muscle tissue that’s causing the tachycardia can be destroyed (ablated). This is done using a catheter procedure called catheter ablation.
• Long-term use of medication is a good way to stabilize the heart rate in many people. For instance, sometimes children and teenagers who regularly take medication don’t need a defibrillator as a result.

Longer-lasting episodes of ventricular tachycardia must be treated urgently in a hospital to restore a normal heart rhythm and prevent possible complications.

If the tachycardia threatens to cause circulatory failure, it can be stopped by delivering controlled electric shocks under brief general anesthesia. That involves pressing or taping electrodes to your chest. The brief burst of electricity stops the rapid heartbeat, allowing the heart to beat at a normal rate again. This procedure is called electrical cardioversion. The possible risks include redness or burns where the electrodes were placed on the skin, as well as reactions to the anesthetic such as breathing problems, blood circulation problems, nausea and vomiting.

Electrical cardioversion is sometimes still done even if your circulation is stable during ventricular tachycardia – but only if there’s no reason why you can’t have the anesthetic and an examination has shown that there are no blood clots in your heart. Cardioversion could loosen blood clots in the heart, which could then travel to other parts of the body and block blood vessels there. Alternatively, there are medications that can be injected to try to return the heartbeat to normal. The potential side effects of this treatment include dizziness, difficulty breathing, headache, or a drop in blood pressure. Because the medications affect the complex electrical pathways in the heart, they can also trigger other types of abnormal heartbeat. Sometimes, ventricular tachycardia is stopped by doing a catheter procedure on the heart.

Another aim of treatment is to get rid of the underlying causes of the ventricular tachycardia, if possible. You might stop taking medication that triggers the rapid heartbeat, for example. It is also important to treat any existing chronic diseases as effectively as possible – for instance, by regularly taking ACE inhibitors to treat heart failure.

If you have frequent episodes of ventricular tachycardia, the symptoms and the fear of life-threatening complications can be very distressing. It can also be difficult to decide what sort of preventive treatment to use. It is important to have an in-depth talk with your doctor about the pros and cons of the various treatment options. A decision aid can help you to discuss any questions you still have and figure out what’s important to you personally. It may also be helpful to talk with others who are facing similar decisions – for example, in a support group.

People who opt for an implantable cardioverter-defibrillator (ICD) will generally have it for the rest of their life. That can mean limitations in everyday life, for loved ones as well. Many people are afraid of the moment when the device gives off an electric shock. It can be painful. But people who are unconscious because of the tachycardia don’t feel anything. Some people are afraid the device will be activated by accident, so they avoid strenuous physical activity. That’s not necessary, though.

An ICD can also have a major impact on your job: If you work with high-current electricity or strong magnetic fields, you need to take special precautions. You may not be allowed to drive vehicles much in your job, either. But in your private life you can usually get back behind the wheel within three months of having the defibrillator implanted.

Electronic and magnetic devices can disrupt the function of the implanted defibrillator. This is usually harmless and only temporarily affects the device programming without having any serious consequences. But extra bursts of electricity might be given off, too, which can be unsettling. According to experts, there’s no need to keep a certain safety distance between an implanted defibrillator and mobile devices nowadays – for instance, when listening to music or talking on the phone. But you shouldn't hold your phone or headphones right next to the defibrillator. People are also advised to stay more than ten centimeters (about four inches) away from wireless charging stations. A distance of 25 centimeters (about ten inches) is recommended for induction stoves, so you can still cook on them. The recommended distances are typically listed in the user manual.

At security checkpoints (for example, at the airport) you should show your ICD identification card and mention that you have an ICD. You can then usually pass through without an electronic body scan. Certain medical examinations, such as MRI scans, are more dangerous for people who have an ICD. They are possible with some types of ICD, though.

Overall, you can go about your everyday life without too many limitations, as long as you follow the precautions described here. If you are unsure about anything, you can ask your doctor or the ICD manufacturer.

When people are ill or need medical advice, they usually go to see their family doctor first. You can read about how to find the right doctor in our topic “Health care in Germany.” If you already have a cardiologist, you should ask them for advice. Our list of questions can help you to prepare for your appointment.