When your heart is beating too fast, too slow, or in some other unusual way, the condition is called an arrhythmia. It’s often a sign that there’s a problem with the electrical system that regulates the rhythm of your heart.
A racing heart rate is known as tachycardia. If it is fast and an arrhythmia, it is called tachyarrhythmia and it can be a potentially serious medical problem.
You may be able to sense a tachyarrhythmia, but sometimes a faster-than-normal heart rate isn’t always noticeable. A monitor that measures your heart rate can be used to diagnose tachyarrhythmia. Various heart problems can accelerate your heart rate, as can certain medications and other health conditions.
Continue reading to learn about the symptoms, types, causes, and treatment options for tachyarrhythmia.
Your heart rate is controlled by an electrical system. It tells the heart when to pump oxygenated blood out to the body and when to relax and allow the heart to fill up with blood again. When this electrical circuit is disrupted, an arrhythmia occurs.
Changes to this circuit can cause your heart rate to speed up, slow down, flutter, or beat in an uncoordinated pattern.
Along with the abnormal rhythm, tachyarrhythmia causes a heart rate of more than 100 beats per minute (bpm) for an adult. A normal resting heart rate is between 60 and 100 bpm.
If you’ve just completed an intense aerobic workout, you should expect your heart rate to be elevated for a little while and then return to normal. In tachyarrhythmia, the heart rate accelerates for reasons unrelated to aerobic activity or other normal causes of a quickened heart rate.
Tachyarrhythmia isn’t one condition. There are several types of tachyarrhythmias, with each one representing a different problem with electrical conduction in the heart.
Because changes to your heart’s electrical conduction system can occur in a variety of places, it makes sense that there are different types of tachyarrhythmia. Examples of tachyarrhythmia include:
- Multifocal atrial tachycardia. Multifocal atrial tachycardia is a rare condition in which the atria send too many signals to the ventricles. It’s usually seen in people with cardiopulmonary conditions.
- Paroxysmal atrial tachycardia. Paroxysmal atrial tachycardia causes the atria to go in and out of atrial tachycardia.
- Paroxysmal supraventricular tachycardia. Paroxysmal supraventricular tachycardia occurs when a short circuit along the usual pathway of electrical signals in the heart causes the signal to speed up instead of following its normal, slower pattern. This type is also typically episodic.
- Sinus tachycardia. Sinus tachycardia occurs when the sinus node — the heart’s natural pacemaker — sends out signals that cause the heart to beat faster than normal. You may have a temporary acceleration of your heart rate due to intense exercise, caffeine, or other normal triggers. Sinus tachycardia can become a problem when it occurs without an obvious trigger, which is called inappropriate sinus tachycardia.
- Ventricular tachycardia. Ventricular tachycardia is a tachyarrhythmia that beings in the ventricles. This condition causes a heart rate of more than 100 bpm with at least three irregular heartbeats in a row. This can be life threatening.
- Atrial fibrillation. Atrial fibrillation is the most common type of heart arrhythmia, in which the two upper chambers of your heart (atria) are affected. This disrupts blood flow to the ventricles or the lower chambers, and then throughout the rest of your body.
- Atrial flutter. Atrial flutter is a type of abnormal heart rhythm. It occurs when the upper chambers of your heart beat too fast, causing the bottom chambers to also beat faster than normal.
Symptoms of tachyarrhythmia can vary, depending on the type of arrhythmia you’re experiencing. In general, the following symptoms are common to most kinds of tachyarrhythmia:
- heart palpitations (specifically the sensation that your heart is racing and beating much faster than normal)
- elevated pulse
- chest pain or tightness
- shortness of breath
Some people may not have any noticeable symptoms. Your tachyarrhythmia may be picked up while having your heart rate measured or when a doctor listens to your heart during a routine examination.
There are several tests a doctor may order to evaluate an elevated heart rate. This will help them look for any obvious problems with the heart that may have triggered your tachyarrhythmia. Some of these tests may include:
- Electrocardiogram (ECG). An ECG is a recording of your heart’s electrical activity. Electrodes are placed on your chest and send signals through wires to a machine that records the rhythm and rate of your heart.
- Holter monitor. A Holter monitor is a wearable device that can detect an arrhythmia any time during the time period you wear the device. It can be especially helpful if an ECG doesn’t happen to catch a tachyarrhythmia event while you’re at the doctor’s office.
- Cardiac event monitor. This is a small device you can clip to a belt or keep in a pocket for about 2 to 4 weeks. When you feel a tachyarrhythmia, you place the monitor against your chest to capture a brief ECG reading. Many devices will also autocapture the arrhythmia, even if you don’t push the button.
- Implantable loop recorder. This device records your heart’s activity like an event monitor, but it’s implanted under your skin. You or your doctor can program it to record an arrhythmia when it happens, or you can trigger the device to record with a remote.
- Mobile cardiac telemetry (live arrhythmia monitor). These devices are worn continuously to pinpoint irregular rhythms. They can then deliver data to you or your doctors immediately through a mobile app. Examples include the Apple Watch and the AliveCor mobile device.
Additional factors and tests a doctor might use to assess your condition may include:
- complete blood count
- electrolytes and urea
- liver and thyroid function
- blood glucose
- arterial blood gas
- drug screening
- pregnancy test
When making a diagnosis, a doctor will also review any other symptoms you’re having, as well as your personal and family medical history. They will also want to know how long you’ve been experiencing a fast heart rate, how long tachyarrhythmia episodes last, and what activities you’re doing prior to your heart rate accelerating.
The disruption to your heart’s electrical system can be triggered by seemingly harmless behaviors and mild health issues, as well as very serious medical issues. Anything that stresses the heart muscle can be problematic.
Conditions that can cause a rapid heart rate include:
- Postural orthostatic tachycardia syndrome (POTS). POTS describes a group of neurological conditions in which the body sends abnormal signals to the brain and heart when you change positions (such as sitting to standing). A common symptom of POTS is tachyarrhythmia.
- Wolff-Parkinson-White syndrome. Wolff-Parkinson-White syndrome is a congenital heart condition in which the heart has an extra electrical pathway. It can be a potentially serious medical condition. Medications may help ease symptoms, and cardiac ablation may be effective in destroying the abnormal pathway.
Some of the more common risk factors for tachyarrhythmia include:
For mild cases of tachyarrhythmia, treatment may not be necessary. However, if the condition worsens or is threatening to cause heart problems, a doctor may then prescribe any of several types of arrhythmia medications to restore a healthy heart rate. Types of medications include:
- beta-blockers, which help slow your heart rate and force of contraction by preventing adrenaline (epinephrine) from binding to beta receptors
- calcium channel blockers, which also help slow the heart rate and force of contraction
- antiarrhythmic drugs, which affect the electrical conduction in the heart
Cardiac ablation is another widely used treatment option. A doctor may use heat energy (radiofrequency ablation) or cold energy (cryoablation) to destroy a tiny portion of heart tissue believed to be the source of the abnormal electrical activity. This may be done using a catheter that is guided up to the heart through a blood vessel in the upper thigh or the forearm.
Similarly, a treatment called external cardioversion is often helpful when medications or other treatments have failed. In this procedure, two patches are placed on your chest. These are attached to a defibrillator that delivers an electrical shock to reset your heart rhythm. This is done under general anesthesia.
Internal cardioversion is less common. This procedure involves threading two catheters up through a blood vessel starting in the groin and ending at the heart. The catheters deliver a low-level electrical shock to the heart muscle in hopes of returning it to a normal rhythm.
If you have tachyarrhythmia, the condition may have no impact on your health, quality of life, or longevity. If your type of tachycardia is more serious and requires medication or a therapeutic procedure, you can still enjoy a long, healthy life — with the understanding that your heart condition is a permanent one.
You will need to work closely with a cardiologist, take your medications as prescribed, and make certain heart-healthy choices. This might mean giving up smoking or limiting caffeine and alcohol.