What Is the Main Reason for Bradycardia?

1. Sick sinus syndrome: Develops when the heart's natural pacemaker, the sinus node, fails to consistently initiate each heartbeat. The heart rate is slow and erratic because it beats at longer or intermittent intervals. Older adults are more likely to experience sick sinus syndrome, however, it can happen to anyone.
   • The following are risk factors for sick sinus syndrome:
     • Previous heart surgery
     • Atherosclerosis
     • Blood pressure medications
     • Age older than 70 years
2. Heart block: The electrical signal that contracts the atria (top chambers of the heart) does not always reach the ventricles. Heart block could be congenital or acquired (after a heart attack). 2:1 heart block occurs when the ventricles only contract once every two times the atria contract.
   • Complete heart block: The upper and lower chambers of the heart are unable to communicate with one another.
   • Congenital heart block: Present from birth
   • The following are risk factors for heart block:
     • Heart illness or a heart attack in the past
     • Exposure to specific poisons like lead or insecticides
     • Specific drugs, such as digitalis
     • Lyme disease
3. Electrolyte imbalances: Your heart rate could be impacted if you do not consume enough electrolytes, including calcium, magnesium, and potassium.
4. Infections: If the bacteria that most commonly cause streptococcal infections are not promptly treated, they can potentially harm your heart, particularly your heart valves.
5. Inflammation: Inflammation of the heart's pericardium (the sac that surrounds and cushions your heart), muscle (myocarditis), or inner lining (endocarditis).
6. Rheumatic heart disease and fever: When a bacterial illness, such as strep throat, is not treated right away, rheumatic fever may develop. A few years later, rheumatic heart disease develops because of rheumatic fever.
7. Drugs: Narcotic pharmaceuticals, lithium, beta-blockers, antiarrhythmic drugs, and antidepressants. Cannabis (marijuana), a substance used recreationally, can cause bradycardia.
8. Lyme disease: Brought on by bacteria transmitted through tick bites. This infection, also called borreliosis, might harm your heart if you wait too long to get treatment.
9. Chagas disease: Similar to Lyme disease but brought on by a parasite present in triatomine or “kissing bugs,” which are blood-sucking insects.
10. Other conditions include:
    • Severe hypothermia (cold) or hypoxia (not enough oxygen in the blood)
    • Obstructive sleep apnea
    • Hypothyroidism (underactive thyroid)
    • High pressure inside the skull (intracranial pressure)
    • Duchenne muscular dystrophy
    • Long Q-T syndrome
    • Scleroderma
    • Lupus
    • Anorexia nervosa (bradycardia may be brought on by this eating disorder due to poor metabolism)

Some may experience symptoms, fainting, or dizziness, due to bradycardia that need to be investigated and addressed.

The following indications and symptoms may result from slower than normal heartbeats (bradycardia), which may hinder the brain and other organs from receiving enough oxygen:

• Chest pain
• Confusion or issues with memory
• Unsteadiness or faintness
• Prone to easily getting tired during exercising
• Fatigue
• Syncope or fainting or nearly fainting
• Breathing difficulty
• Disturbed sleep

Bradycardia is frequently linked to heart disease of some kind that has damaged the heart tissue. Bradycardia can become more likely for any reason that raises the risk of heart issues. 

Heart disease risk factors include:

• Alcohol abuse
• Recreational drug use
• Psychological discomfort or stress
• Older age