Heart palpitations (due to paroxysmal atrial tachycardia)

Even healthy people’s hearts sometimes beat very fast when they are exercising or under stress – this is perfectly normal. However, when “heart palpitations” or a “rapid heartbeat” (tachycardia) are experienced, the heart beats very quickly due to illness.

This article discusses heart palpitations due to paroxysmal atrial tachycardia (paroxysmal supraventricular tachycardia). With this condition, the heart suddenly beats very fast. The heartbeat is too fast, but it remains regular. The heart palpitations usually settle on their own after a while. This form of arrhythmia does not usually have any serious complications.

However, there are other, more serious conditions that can cause heart palpitations, including atrial fibrillation. In such cases, the heartbeat is also irregular.

If the heart suddenly beats very fast, it can often be felt as a racing heart (tachycardia) or palpitations. The heart rate is usually between 180 and 200 beats per minute. But it can also be slightly below or above that. This can be alarming and uncomfortable. Possible symptoms are dizziness, nausea, chest pain, and shortness of breath. More rarely, people may faint (syncope) and fall as a result. Some people have to pass a lot of urine after an episode.

For a healthy person, how often the heart beats depends on their physical and psychological stress levels. For example, exercise, stress or feeling nervous make the heart beat faster. The sinus mode in the right atrium controls how the heart rate adapts to the additional strain. 

With paroxysmal atrial tachycardia, the cause of rapid heart is usually a disruption of the AV node. This is located between the atria and ventricles. If the AV node is working normally, it conducts impulses from the atria to the ventricles.

In people with atrial tachycardia, this conduction may be disrupted. If this happens, impulses become “trapped” in the AV node, where they continue to move in a circular pathway. The AV node then transmits too many impulses to the ventricles. This means that the heart beats very fast.

The condition may also occur if a person is born with additional conduction pathways between the atria and ventricles. These form a short circuit, so that an impulse is conducted into the ventricles but is also conducted back in the direction of the atria and may then move in a loop between the ventricles and atria.

Fast defective impulses can also cause this. They develop in the atria and trigger a heartbeat that is too rapid.

Another possible trigger is a heartbeat that occurs outside of the heart’s normal rhythm (this is known as an extrasystole). Extrasystoles also occur in healthy people every now and then spontaneously and do not cause any symptoms.

Heart palpitations can also be caused by changes in a person’s salt intake or consumption of alcohol or drugs.

Approximately 2 to 3 people in every 1,000 have heart palpitations originating in the atrium or at the junction of the atrium and ventricle. Atrial tachycardia is more common in women than men. The risk increases with age.

However, the condition occurs more often in men and younger people when it is due to additional conduction pathways between the atria and ventricles present at birth.

Usually an episode comes on suddenly, lasts for a few minutes and disappears just as suddenly as it came. For some people, however, the heart palpitations may last for more than an hour.

The time between episodes can vary – some people have several episodes a day, while others have episodes days, weeks or months apart.

The typical symptoms and how they develop usually already indicate paroxysmal atrial tachycardia. But an electrocardiogram (ECG) is needed to make a clear diagnosis, as with all arrhythmias. However, as an episode will not always occur when the person is connected to an ECG device, 24-hour ECG monitoring is often used.

Other tests can be conducted to determine the exact causes and rule out more serious arrhythmias – for instance, a heart ultrasound (echocardiography) or a thyroid test. A special heart catheterization can be used to examine whether there are innate additional conduction pathways between the atria and the ventricles.

To treat heart palpitations due to paroxysmal atrial tachycardia, doctors first need to rule out serious arrhythmias that require different treatments.

People who are otherwise healthy and for whom an occasional rapid heartbeat is not a problem do not usually need any treatment.

There are also simple things people can do to end an episode themselves. For example, it may help to quickly drink a cold glass of water. A special breathing technique known as the Valsalva maneuver has proven to be particularly effective. It involves increasing pressure in the abdomen by breathing in and pressing on the stomach, −as though trying to suppress a hiccup. It is often combined with certain postures, such as holding the legs in a raised position. The maneuver stimulates the vagus nerve – a nerve that sends signals to the heart and can slow the heart rate.

These measures are also the first to be used in medical practices or hospitals. Medication is only injected when they do not work. It’s rare for an episode to have to be ended by an electric shock (cardioversion).

If the episodes are very stressful for those affected, there is the option of permanently suppressing them. Medication or cardiac catheterization will be considered.

For more detailed information, e.g. about home remedies for heart palpitations, see gesundheitsinformation.de.