<unk>  is a collection of heart rhythm disorders that include:<unk>  bradycardia -- slow heart rates from the natural pacemaker of the heart<unk>  pauses or arrest -- when the natural pacemaker of the heart stops working for periods of time
People with these disorders may also have other abnormal heart rhythms, such as:
Atrial tachycardia -- fast heart rate that starts in the upper chambers of the heart (atria)
Bradycardia-tachycardia -- alternating slow and fast heart rhythms
Sick sinus syndrome
Siccardi syndrome
Aicardi syndrome
Adams-Stokes syndrome
Acute coronary syndromes
Stress cardiomyopathy
Obesity cardiomyopathy
Avasthey syndrome