Sick sinus syndrome is a collection of heart rhythm disorders that include:
- Sinus bradycardia — slow heart rates from the natural pacemaker of the heart
- Sinus pauses or arrest — when the natural pacemaker of the heart stops working for periods of time
People with these disorders may also have other abnormal heart rhythms, such as:
- Atrial tachycardia — fast heart rate that starts in the upper chambers of the heart (atria)
- Bradycardia-tachycardia — alternating slow and fast heart rhythms
Bradycardia-tachycardia syndrome; Sinus node dysfunction
Causes, incidence, and risk factors
Sick sinus syndrome usually occurs in people older than 50. The cause is often scar-like damage to the heart’s conduction system.
In children, a common cause of sick sinus syndrome is heart surgery, especially on the upper chambers.
Sick sinus syndrome is uncommon. Sinus bradycardia occurs more often than the other types.
Tachycardias that start in the upper chambers of the heart may be part of the syndrome. These include atrial fibrillation, atrial flutter, and atrial tachycardia. A period of elevated heart rates is typically followed by very slow heart rates when the tachycardia ends.
Abnormal heart rhythms are often made worse by medications such as digitalis, calcium channel blockers, beta-blockers, and anti-arrhythmics.
Usually, no symptoms occur. Symptoms that do occur are may mimic those of other disorders.
Symptoms may include:
Chest painor angina Confusionor other changes in mental status Faintingor near-fainting Fatigue Dizzinessor light-headedness
- Sensation of feeling the heart beat (
palpitations) Shortness of breath, possibly only with activity
Signs and tests
Sick sinus syndrome may cause symptoms of
An intracardiac electrophysiology study (
Exercise testing has not been proven very effective as a screening tool.
You may not need treatment if you do not have any symptoms. Your doctor will review the medicines you take to make sure they are not making your condition worse. Do not stop taking any medication unless your doctor tells you to do so.
You may need a permanent implanted pacemaker if your symptoms are related to bradycardia (slow heart rate).
A fast heart rate (tachycardia) may be treated with medications. Sometimes a procedure called radiofrequency ablation is used to cure tachycardia.
The syndrome is progressive, which means it usually gets worse over time.
The long-term outlook is excellent for people who have a permanent pacemaker implanted.
- Decreased exercised capacity
- Fainting (syncope)
- Falls or injury caused by fainting
- Heart failure
- Poor heart pumping
Calling your health care provider
Call for an appointment with your health care provider if you experience spells of light-headedness, episodes of fainting, palpitations, or other symptoms.
Keeping your heart healthy by eating a well-balanced diet and exercising can prevent many types of heart disease.
It may help to treat related disorders. You may need to avoid some medications, based on your health care provider’s advice.
Many times, the condition is not preventable.
Related:Heart pacemaker – discharge, Stable angina, Heart pacemaker