Sick sinus syndrome is a group of heart rhythm problems due to problems with the sinus node that includes sinus bradycardia, sinus pauses, recurrent episodes of fast heart rate, tachy-brady syndrome, etc. Sick sinus syndrome most often occurs in elder people (greater than 50yrs). Most common cause of sick sinus syndrome in children is heart surgery on upper chambers. Coronary heart disease, high blood pressure, and aortic and mitral valve diseases may occur as comorbidity of sick sinus syndrome. Symptoms may include angina, Confusion ,fainting, fatique, dizziness. The diagnosis tools are ECG, holter monitor, event recorder, implantable loop recorder. Medicines like digitalis, calcium channel blockers, beta-blockers, and antiarrhythmics may alter the function of sinus node, People with sick sinus syndrome eventually need a permanent artificial pacemaker to maintain a regular heartbeat. Keyword: bradycardia, tachy-brady syndrome, holter, ECG, pacemaker