Function

• The sinus node is the area of the heart which produces the electrical impulses, similar to a pacemaker. It is responsible for controlling the rhythm of the heart, which is normally between 50 to 120 beats per minute (bpm).
  
  

Significance

• Conditions associated with sinus node disease are inappropriate sinus bradycardia (slow heart rate, not caused by medication); sinoatrial exit block (missed heartbeats); tachy-brady (fluxuating fast and slow heartbeats) syndrome; and sinus arrest and/or asystole (paused heartbeat).
  
  

Causes

• Diseases that are a contributing factor to sinus node disease include sarcoidosis (nodules); Chagas disease (parasitic infection); cardiomyopathy (heart muscle disease); amyloidosis (buildup of amyloid protein); and coronary artery disease.
  
  

Symptoms

• Individuals with sinus node disease can have the condition without any symptoms. Heart arrhythmia, tachycardia (increased heartbeat), palpitations (throbbing heartbeat), anxiety, syncope (fainting) and dizziness are sinus node disease symptoms.
  
  

Treatment

• The treatment options for sinus node disease include medications to treat the symptoms and implanting an artificial pacemaker to regulate the heart's rhythm.