What Is Sick Sinus Syndrome?

Sick sinus syndrome (SSS) is a condition that affects the heart’s natural pacemaker, called the sinoatrial (SA) node. The SA node controls the timing of each heartbeat. When it does not work properly, the heart may beat too slowly, pause unexpectedly, or switch between slow and fast rhythms.

SSS can develop from conditions that damage the heart’s electrical system. Common causes and risk factors include:

• Aging
• Coronary artery disease
• Previous heart attack
• Heart failure or cardiomyopathy
• Atrial fibrillation
• Certain heart medicines
• Hypothyroidism
• Inflammatory or inherited heart conditions

SSS is most common in older adults and is often linked to changes in the heart’s electrical system that occur with aging.

Symptoms

Some people with SSS have few or no symptoms at first. Others may notice symptoms that affect daily activities or exercise.

Symptoms may include:

• Dizziness or lightheadedness
• Fainting
• Fatigue or weakness
• Shortness of breath
• Heart palpitations
• Trouble exercising or staying active

How Is It Diagnosed?

Healthcare providers diagnose SSS by evaluating symptoms and monitoring heart rhythm. Because abnormal rhythms may come and go, testing may happen over several days or weeks.

Tests may include:

• Electrocardiogram (ECG)
• Holter monitor or event monitor
• Implantable loop recorder
• Stress testing
• Echocardiogram
• Electrophysiology studies in selected cases

These tests help providers identify abnormal heart rhythms and check overall heart function.

How Is It Treated?

Treatment depends on the severity of symptoms and the cause of the abnormal rhythm.

Providers may first adjust medicines that affect heart rate or treat related health conditions. If symptoms continue, many patients benefit from a pacemaker. A pacemaker is a small device placed under the skin that helps keep the heart beating at a steady rate.

Healthy lifestyle habits can also support heart health, including:

• Staying physically active
• Eating a heart-healthy diet
• Maintaining a healthy weight
• Controlling blood pressure and cholesterol
• Avoiding smoking

With proper treatment and follow-up care, many people with SSS are able to manage symptoms and stay active.