Most people with sick sinus syndrome have few or no symptoms. Symptoms may be mild or come and go — making them difficult to recognize at first. Signs and symptoms of sick sinus syndrome may include: 
A sensation of rapid, fluttering heartbeats (palpitations)
Chest pain or discomfort
Confusion
Dizziness or lightheadedness
Fainting or near fainting
Fatigue
Shortness of breath
Slower pulse (bradycardia)
