Atrial flutter

Atrial flutter generally makes the heart beat too quickly, often up to 150 beats per minute. People might notice that as an unpleasant racing heart (palpitations). Some people feel like their chest is tightening. Dizziness and feeling faint with a brief loss of consciousness are also possible.

Longer-lasting atrial flutter in particular can have a negative effect on physical fitness, making you feel weak and quickly get out of breath during physical exercise.

Atrial flutter is often caused by scar-like changes to the heart muscle resulting from heart diseases such as coronary artery disease (CAD) or following heart surgery. But myocarditis, heart valve diseases and other pathological changes to the heart muscle (cardiomyopathy) are other possible causes.

What leads to atrial flutter and an overly fast heart rate? The sinus node normally sets the rhythm for how the heart beats: It sends an electrical signal to the atria. The atria then contract and pass this signal on to the ventricles. After that, the atrial tissue relaxes again until the sinus node sends the next signal.

Atrial flutter can develop if a signal is not passed on and gets “stuck” in the atrium because of a previous heart condition: The impulse than usually circles around the heart valve that connects the right atrium and the right ventricle and repeatedly stimulates the heart muscle cells in that area. The stimulation spreads to all of the tissue in the atrium that then contracts at a very high frequency: The atria then beat around 250 to 300 times per minute.

But this high frequency isn’t passed on exactly to the ventricles: In most affected people, only every other atrial beat makes the ventricles contract. But the heart still beats about 150 times per minute, which is too fast.

Atrial flutter can also develop as a result of atrial fibrillation that has been treated with medication. In rare cases, atrial flutter still develops even though the heart muscle is healthy. Metabolic disorders might then be the cause, especially an overactive thyroid (hyperthyreosis).

Men are at more risk of atrial flutter than women. That risk increases with age. Smoking is another risk factor.

Atrial flutter is the second most common heart rhythm disorder of the atria after atrial fibrillation. Experts estimate that around 1 out of 1,000 people develop atrial flutter in the United States each year. It is not clear how often the heart rhythm disorder is diagnosed in Germany.

Atrial flutter often develops suddenly, usually lasts for several days, and then goes away on its own. If left untreated, sooner or later it might come back again. Atrial flutter that comes and goes like this is called "paroxysmal" atrial flutter, and "persistent" if it doesn't go away and remains constant.

It is assumed that, like atrial fibrillation, atrial flutter significantly increases the risk of blood clots forming in the atria. A blood clot can block a blood vessel if it passes into the ventricles and is pumped into the lungs or elsewhere in the body. If that happens in the brain, it leads to a stroke.

Some people have both atrial flutter and atrial fibrillation. The two conditions can overlap.

The heart muscle can be damaged if the atrial flutter persists for a long time. If the muscle loses strength it can lead to heart failure.

Falls and serious injuries can result if the atrial flutter causes dizziness, fainting or even unconsciousness.

Atrial flutter can be detected using electrocardiography (ECG). Doctors use it to see how quickly the atria and ventricles are beating. The ECG even shows whether one specific area of the right atrium is affected by atrial flutter, which is considered to be "typical" atrial flutter.

The disorder can no longer be detected if an ECG is only carried out once the atrial flutter has gone away on its own. A Holter monitor can then help: It records the electrical activity in the heart for 24 hours, or sometimes for several days. If atrial flutter occurs during that time, it is visible in the analysis. An event recorder can help if there was no episode during that period. This is a small device that is implanted under the skin and records the heart rhythm for several years.

Along with an ECG, a transesophageal echocardiogram (TEE) is an important test: It is used to check whether blood clots have already formed in the atria. Like gastroscopy, the doctor inserts a tube through your food pipe. From that location your atria can be examined very closely.

Other tests such as a stress ECG or a blood test are sometimes done to measure thyroid hormone levels to find what is causing the atrial flutter.

Doctors generally try to treat acute atrial flutter by restoring the heart’s normal, slower rhythm. That can usually be done using a burst of electrical current, similar to resuscitation. This treatment is called cardioversion or electrical cardioversion.

If you already have a defibrillator or pacemaker, the heart’s normal rhythm can also be restored using the implanted device. These devices briefly stimulate the heart to an even higher rate, which makes the flutter stop. The heart then beats normally again.

If there is a risk of blood clots already having formed in the atria, you will be given medication to stop the blood from clotting.

If cardioversion isn’t possible or you don't want to have it done, medication can be used to slow down the increased heart rate caused by the atrial flutter (rate control). The ventricles then beat more slowly, but the fluttering in the atria doesn't change. That is why there is still a risk of blood clots forming there and causing a stroke. That is especially true if there are other risk factors such as old age.

Doctors usually recommend catheter ablation to make sure that the atrial flutter doesn’t keep coming back. The procedure destroys a small amount of heart tissue in the area that the atrial flutter normally starts. That can stop the electrical signals from taking the wrong path and causing atrial flutter over the long term.

This decision aid for cardiovascular diseases can help if your doctors have recommended catheter ablation or other treatment: It makes it easier to consider which treatment is the most suitable together with your doctor.

Risk factors such as smoking and obesity can increase the likelihood of developing heart rhythm disorders such as atrial flutter and other heart diseases. That is why it is important to lead a healthy life in addition to any treatment. There are a number of other things you can do to keep your heart healthy.

When people are ill or need medical advice, they usually go to see their family doctor first. In our topic “Health care in Germany” you can read about how to find the right doctor – and our list of questions can help you to prepare for your appointment.