Sinus node dysfunction can progress rapidly. It is also a chronic disease. When there is a complete AV block with episodes of asystole, patients experience syncope.

Cerebral stroke is an important potential complication to note, especially in patients with concomitant atrial fibrillation. These patients are treated with anticoagulation therapy. 

Survival rates are better for patients with sinus node dysfunction compared to patients with complete AV block. The survival in sinus nodal dysfunction depends on the presence of other comorbidities such as stroke, heart failure, and congestive heart disease.