There are several types of slow heart rates (bradycardias
or bradyarrhythmias). Each type carries a specific risk of complications and
treatment options. Some of the types are described here.
When a person has sinus
bradycardia, the heart rate is less than 60 beats per minute. This slow heart
rate might be normal. This type of slow heart rate is often seen in healthy,
Risk of complications? This type is not likely to cause complications, unless the heart rate is very
slow (less than 40 beats per minute).
Treatment. It rarely requires treatment unless it causes
symptoms. Then, a pacemaker may be implanted if there is no cause
that can be easily treated.
Sinus pause (also called sinus arrest)
sinus pause, the heart may miss one or more beats because its
natural pacemaker fails to activate the electrical
system throughout the rest of the heart.
Risk of complications? Yes, depending on the cause.
Treatment. If this occurs often or over an extended period of
time, a person may have symptoms now and then and need a pacemaker. If there
is an cause that is identified, that condition may be treated
Sick sinus syndrome
Sick sinus syndrome happens when the normal pacemaker of the heart (the sinus node) does not work
properly. Various irregular heart rates (arrhythmias) or combinations of
arrhythmias can happen. People with this syndrome can have
slow arrhythmias or a combination of fast and slow arrhythmias.
In tachy-brady syndrome, also called tachycardia-bradycardia syndrome, the
heart sometimes beats too quickly (tachy) and sometimes beats too slowly
(brady). This abnormal heart rhythm problem is often seen in people who have
been diagnosed with
atrial fibrillation. It can occur when the heart's
natural pacemaker is damaged.
Risk of complications?
Yes. You may have symptoms such as palpitations and lightheadedness. You might pass out. You might have a higher risk of stroke.
Treatment. Treatment may include a pacemaker to prevent the heart from
beating too slowly. Medicines might be used to prevent the heart from
beating too fast. Blood-thinning medicines are used to help prevent a stroke.
Heart block refers to an abnormality in the way
electricity passes through the normal electrical pathways of the heart. The
abnormality "blocks" the electrical impulse from continuing through the normal
pathways and usually results in a slower heart rate.
Olgin J, Zipes DP (2012). Bradyarrhythmias section of Specific arrhythmias: Diagnosis and treatment. In RO Bonow et al., eds., Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 9th ed., vol. 1, pp. 813–824. Philadelphia: Saunders.
Vijayaraman P, Ellenbogen KA (2011). Bradyarrhythmias and pacemakers. In V Fuster et al., eds., Hurst's The Heart, 13th ed., pp. 1025–1057. New York: McGraw-Hill Medical.
Primary Medical Reviewer
E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
How this information was developed to help you make better health decisions.