How could we improve it?

This article contains false or inaccurate information.

Please tell us what was incorrect.

Please note that you do not need to fill this detail if it's inconvenient for you. Click Send My Opinion below to continue reading our site.
This article doesn't provide enough info.

Please tell us what was missing.

Please note that you do not need to fill this detail if it's inconvenient for you. Click Send My Opinion below to continue reading our site.
Hmm... I have a question.

We’re unable to offer personal health advice, diagnosis, or treatment, but we welcome your feedback! Just type it in the box below.

If you're facing a medical emergency, call your local emergency services immediately, or visit the nearest emergency room or urgent care center.

Or copy link

Everything You Need To Know About Sinus Arrhythmia

Everything You Need To Know About Sinus Arrhythmia

The heart is one of the organs in your body that responds to everything you do and feel. However, the heart is also susceptible to many health conditions. According to the World Health Organization, cardiovascular diseases are the leading cause of death in both sexes all across the globe. Even the beating of the heart can be vulnerable to disease and disorders like sinus arrhythmia. What is sinus arrhythmia or sick sinus syndrome?

The Natural Pacemaker of the Heart

The part of the heart responsible for making heartbeats happen is the sinoatrial node (SA node). This node is the heart’s natural pacemaker. The SA node is a cluster of cells in the atrium of the heart, which sends an electrical impulse to the walls of the atrial. This causes the heart to contract. It plays important role of regulating heartbeats by constantly firing impulses.

What Is Sinus arrhythmia?

Sinus arrhythmia or sick sinus syndrome encompasses disorders in the beating of the heart caused by the malfunctioning of the SA node. Arrhythmia is a term that describes an irregular heartbeat.

Conditions under sick sinus syndrome:

Sinus Bradycardia

Sinus bradycardia is a type of sick sinus syndrome that is characterized by a slower than normal heartbeat. A person with sinus bradycardia typically has a heart rate of less than 60 beats per minute. A normal SA node should be able to fire at least 60 to 100 beats per minute.

A particular type of sinus bradycardia called physiologic sinus bradycardia. It is considered harmless, as it doesn’t cause any symptoms. This usually happens to athletes or children. However, sinus bradycardia that’s associated with other types of heart disease can be fatal. A slower than normal heartbeat can lead to reduced blood supply to the different parts of the body, leading to much more serious diseases or conditions.


Tachycardia is a condition where the heart beats faster than it normally would. A person with tachycardia usually has a heart rate of more than 100 beats per minute. Sometimes, a hastened heartbeat isn’t a sign of a disorder. The heartbeat can speed up due to many factors such as exercise or stress. However, tachycardia occurs even if there isn’t a reason for the heart to speed up.

The most common type of tachycardia is known as atrial fibrillation. This type of tachycardia is a “quivering” type of movement that results in the heart not being able to pump blood effectively.


This condition is a combination of both previously mentioned sick sinus syndromes. In Bradycardia-Tachycardia, the heart has an irregular rate that may be too slow or too fast.

Causes of Sinus Arrhythmia

Experts are still unsure about what causes sick sinus syndrome. One possible cause is age. Over the years, the SA node can accumulate damage that can cause it to malfunction and cause heart rate irregularities.

Other conditions that can result in sick sinus syndrome are:

  • Heart diseases such as coronary heart disease, cardiomyopathy, and other inflammatory conditions of the heart.
  • Certain medications for hypertension or Alzheimer’s such as antiarrhythmics or beta blockers.
  • History of a heart attack.
  • Trauma that results in scarring of the SA node, typically from heart surgery.
  • Excess thyroxine in the body resulting from hyperthyroidism.

Symptoms of Sinus Arrhythmia

Most of the time, sick sinus syndrome does not cause any notable symptoms. Most patients rule out the symptoms as unrelated to a heart condition.

Symptoms of this condition include:

  • Palpitation or feeling that your pulse is slower than it should be
  • Feeling lightheaded or dizzy
  • Breathlessness or dyspnea
  • Faintness or losing consciousness
  • Pain or discomfort that’s radiating from the chest
  • Exhaustion or fatigue

Complications of Sinus Arrhythmia

If left untreated, this condition can lead to irreversible damage of the heart tissue. This is because over time, irregularities in your heartbeat can affect the functions of the heart and other parts of the body.

Some complications of sick sinus syndrome are the following:

Treatment of Sinus Arrhythmia

Not all cases of sick sinus syndrome require treatment. In fact, many people can still lead long lives despite living with this disease. If the condition is a side-effect of medication, your doctor may take you off those and prescribe another medicine.

Doctors may prescribe blood thinners to reduce the risk of blood clots. Patients who have irreversible or undetermined causes of sick sinus syndrome may also have to wear a pacemaker.

A pacemaker is a device that is implanted in the chest, usually near the collarbone. The pacemaker will automatically detect if your heartbeat becomes irregular, and will send a signal to the heart to help correct its pace.

Learn more about Heart Health here.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Picture of the author
Medical reviewed by Hello Doctor Medical Panel
Written by Ruby Anne Hornillos
Updated Dec 29, 2020