Bradycardia is defined as a slow heart rate or irregular heart rhythm. A healthy heart beats 60 to 100 times per minute, which is necessary to supply oxygen-rich blood to the body. Those with bradycardia experience a heart rate of less than 60 beats per minute, often resulting in dizziness, shortness of breath, and even fainting spells.

The causes of a slow heart rate may include underactive thyroid (hypothyroidism), an electrolyte imbalance, or medicines you may be taking for certain conditions. The treatment for Bradycardia depends on what is causing it, and your doctor will evaluate your current health status and medical history to determine the correct course of treatment.

Causes
Common bradycardia causes include:
-- A hereditary heart defect
-- Certain illnesses or heart medications
-- The natural aging process
-- Scar tissue from a heart attack
-- Sick sinus syndrome (eg, sinus bradycardia or sinus node dysfunction)
-- The heart's natural pacemaker is not functioning correctly
-- Heart block
-- The electrical impulse that travels from the upper to the lower chamber of the heart is irregular or blocked

Bradycardia Symptoms
When your heart beats too slowly, it is not supplying the body with sufficient oxygen. Your doctor will assess and diagnosis your heart condition, but slow heart rate symptoms may include:
-- Dizziness and fainting
-- Chronic lack of energy
-- Shortness of breath
-- Fainting

Risk Factors
Your risk of developing an abnormally slow heartbeat (bradycardia) is greater if you:
-- Have certain types of heart disease
-- Are taking certain medicines
-- Are age 65 or older
-- Have recently had heart surgery