You may have heard the terms arrhythmia and dysrhythmia used in relation to heart health — but is there a difference?

Generally speaking, both of these terms mean the same thing. When someone has an arrhythmia or dysrhythmia, their heartbeat has an abnormal rate or rhythm.

Below, we’ll take a closer look at the terms arrhythmia and dysrhythmia. We’ll also explore different types of abnormal heart rates and rhythms and how they’re treated.

Arrhythmia and dysrhythmia refer to the same type of condition. This is a heartbeat that has an abnormal speed or rhythm.

The “a” prefix in arrhythmia means a lack or an absence of something. In this case, a lack of (normal) rhythm.

Meanwhile, “dys” is a prefix that means something is difficult or doesn’t work properly. The word “dysfunction” is an example of this. In the case of dysrhythmia, this can mean an abnormal rhythm.

As you can see, both terms generally refer to a heart rate with a speed or rhythm that’s different from what’s typically observed. Today, arrhythmia is the term that’s more commonly used.

Your resting heart rate is the number of times your heart beats in a minute while you’re at rest and relaxed. According to the American Heart Association, most people have a resting heart rate that’s between 60 and 100 beats per minute.

Sometimes, a resting heart rate can be faster or slower than normal. There are two terms associated with this:

It’s important to note that a slow heart rate may not always signal a health condition. In fact, people who engage in a high level of physical activity, such as athletes, often have a low resting heart rate.

With heartbeats, it’s not all about fast and slow though. Sometimes, the rhythm or sequence of the beats can be irregular as well. This can include beats that feel premature, irregular, or like your heart “skipped a beat.”

Your heart beats in response to electrical signals that are generated by the sinoatrial (SA) node. You can think of the SA node as your heart’s pacemaker. It’s found in the upper right part of your heart.

This electrical impulse passes through the upper chambers of your heart (atria) and then to the atrioventricular (AV) node. Specialized fibers allow this electrical impulse to then travel from the AV node to the lower chambers of your heart (ventricles).

When any part of this electrical signaling sequence is disrupted through changes in your heart tissue, an arrhythmia can occur. This can occur due to:

Now that you know what can cause an arrhythmia, let’s take a deeper dive into some of the different types of irregular heart rhythms.

Supraventricular arrhythmias

These types of arrhythmia happen in the upper chambers of your heart (atria). There are several different types of supraventricular arrhythmia.

Atrial fibrillation is the most common kind of arrhythmia. With atrial fibrillation, the atria contract very quickly and at irregular intervals. This causes them to be out of sync with the lower chambers of the heart (ventricles).

People that have atrial fibrillation are at an increased risk for several types of complications, such as:

Some additional examples of supraventricular arrhythmias include:

  • Atrial flutter. Atrial flutter is similar to atrial fibrillation in that the atria beat faster than the ventricles, causing the upper and lower chambers of your heart to be out of sync. However, it’s not as irregular as atrial fibrillation.
  • Atrial premature complex (PAC). PACs are a type of arrhythmia where premature heartbeats originate from the atria. When this happens, you may feel heart palpitations, or a skip.
  • Atrial paroxysmal tachycardia (PAT). Atrial paroxysmal tachycardia is a fast heart rate that originates from the atria. Paroxysmal means that the arrhythmia episode starts and ends suddenly. If the episode continues, it is called persistent atrial tachycardia. This usually means a number of skips occur in a row.

Ventricular arrhythmias

These types of arrhythmia occur in the lower chambers of your heart, known as the ventricles. There are several different types of ventricular arrhythmia. Some of the most common include:

  • Ventricular tachycardia. Ventricular tachycardia is a rapid heart rate that originates from the ventricles. This can be dangerous if it happens for longer than a few seconds. Ventricular tachycardia can also lead to the development of ventricular fibrillation.
  • Ventricular fibrillation. Ventricular fibrillation happens when the electrical signals that tell your heart to beat cause the lower chambers of your heart to quiver instead. As a result, your heart cannot pump blood to the rest of your body. This dangerous condition leads to sudden cardiac arrest.
  • Ventricular premature complexes (PVC). With PVC, a premature heartbeat is generated from the ventricles. This is usually a single skip.

Bradyarrhythmias

Bradyarrhythmias are associated with a heart rate that’s slower than 60 beats per minute (bradycardia). Examples of this type of arrhythmia include:

  • Sinus bradycardia. Sinus bradycardia is a type of bradycardia that originates from the SA node, which is the area of your heart that coordinates your heartbeat.
  • Heart block. Heart blocks are due to a problem with electrical signaling from your heart’s AV node. When this happens, electrical signals may not reach the ventricles effectively, causing a slower heart rate.

While some mild arrhythmias may not cause any health complications, more severe arrhythmias can. Some potential complications include:

  • Heart failure. Having an arrhythmia can make it harder for your heart to effectively pump blood to the organs and tissues of your body.
  • Stroke. In some types of arrhythmia, it’s possible that blood can pool in the chambers of your heart. This can increase the risk of blood clots, which can cause a stroke if they travel to your brain.
  • Sudden cardiac arrest. Some types of arrhythmia can cause your heart to suddenly stop. A sudden cardiac arrest can lead to death if it’s not promptly treated.
  • Dementia. Having some types of arrhythmia is associated with dementia and other types of cognitive problems.
  • Arrhythmias that get worse. It’s possible that an existing arrhythmia can worsen over time or lead to another type of arrhythmia.

Because some types of arrhythmia can cause potentially serious complications, it’s a good idea to make an appointment with your doctor if you experience arrhythmia symptoms, such as:

  • a pounding or racing heart that’s not due to physical activity or stress
  • a heart rate that feels slower than normal
  • frequent heart palpitations, which can feel like your heart is fluttering or has skipped a beat

Other symptoms may indicate that your heart isn’t pumping blood as effectively as it should, such as:

In order to diagnose arrhythmia, your doctor will first perform a physical examination. They’ll take your pulse and listen to your heartbeat.

Your doctor will also take your medical history. They’ll ask about:

  • your symptoms
  • lifestyle habits
  • whether there’s a history of arrhythmia in your family

While there are many tests that can help your doctor make a diagnosis, an electrocardiogram (ECG) or an ambulatory arrhythmia monitor is most often used to diagnose arrhythmia. An ECG measures the electrical signals that are made when your heart beats.

In some cases, your doctor may also order an echocardiogram. This test uses sound waves to create live images of your heart. These images can help your doctor see how your heart’s chambers are working and how your blood is flowing through your heart.

The treatment for an arrhythmia can depend on the specific type of arrhythmia you’ve been diagnosed with.

The terms arrhythmia and dysrhythmia both refer to conditions that affect the rate or rhythm of your heartbeat. Arrhythmia is the more commonly used term.

There are many different types of arrhythmias. While some may not cause any complications, others can lead to serious complications like stroke or sudden cardiac arrest.

Because some types of arrhythmia can cause potentially serious complications, it’s important to see your doctor if you have arrhythmia symptoms. Arrhythmia can be treated with medications, medical procedures, or lifestyle changes.