Sick Sinus Syndrome



The sinus node sets the pace of the heart. It creates and sends signals that make the heart beat in a regular pattern. The sinus node's function may be disrupted by:

  • Problems within the heart tissue
  • Toxins, drugs, medicines, or trauma that affects heart tissue

Risk Factors

Sick sinus syndrome is fairly rare. It is more common in older people. Other things that may raise the risk are:

  • Family history of sinus node problems
  • Certain heart problems, such as:
  • Other conditions that can affect the heart such as:
    • Sarcoidosis
    • Amyloidosis
    • Scleroderma
  • Trauma to the heart from surgery
  • Certain medicines, such as:
    • Digoxin
    • Antiarrhythmics
    • Calcium channel blockers
    • Lithium
  • Vasovagal syncope



At first, sick sinus syndrome may not have symptoms, or the symptoms may come and go.

When symptoms happen, they may be:

  • Heart flutters
  • Fast, skipped, or pounding heartbeats
  • Feeling faint or fainting
  • Dizziness
  • Tiredness


Sick sinus syndrome is often not found unless there are symptoms. The doctor will ask about symptoms and past health. A physical exam will be done. To diagnose the condition, heart tests may be done, such as:

  • ECG—tests electrical activity of the heart
  • Holter monitoring—a device worn to measure heart activity over 24 to 48 hours
  • Electrophysiology study (EPS)—wires are passed into the heart to measure activity— used more often with severe problems



For those with no symptoms, treatment may not be needed. Over time, sick sinus syndrome can raise the risk of atrial fibrillation, heart failure, heart attack, or stroke. As a result, the doctor will need to monitor heart health.

Treatment may be needed if uneven heart patterns disrupt blood flow through the heart. Options may be:

  • Pacemaker—A device may be inserted to send signals to the heart. This will make the heart create a normal rhythm when needed. It is often used with slow heartbeats.
  • Medicine—May help control fast heartbeats or speed up slow heartbeats.

Underlying conditions may also need to be treated.


There are no guidelines to prevent sick sinus syndrome.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.