Bradycardia may be caused by:
-
Normal responses to:
- Deep relaxation
- Being in excellent physical shape
- The heart’s natural pacemaker developing an abnormal rate or rhythm
- The normal electrical conduction pathway being interrupted
- Another part of the heart taking over as pacemaker
A risk factor is something that increases your chance for getting a disease or condition. Risk factors for bradycardia include the following:
- Advancing age
- Hypothyroidism
-
Drugs such as (most commonly used for):
-
Clonidine and other centrally acting alpha-2 adrenergic agonists (
high blood pressure
)
-
Cholinesterase inhibitors (
Alzheimer’s disease
)
- Calcium antagonists (high blood pressure, heart disease)
-
Digitalis and other cardiac glycosides (heart failure and
arrhythmias
)
- Lithium
- Beta-blockers (high blood pressure, heart disease), also used in some eye drops
- Exposure to certain toxins
-
Cardiac disease, such as:
- Heart attack
- Degeneration, calcification, or “wearing out” of the conduction system
- Congestive heart failure
- Valvular failure
- Heart conditions that are inherited or present at birth (congenital heart defects)
- Electrolyte imbalances (high or low potassium levels)
- Sleep apnea
-
Rarely seen with
lupus
or other collagen vascular diseases
- Head injuries
- Hypothermia
- Hypoglycemia
-
Infectious diseases, such as: