Heart block, specifically complete or third-degree heart block, poses a significant threat to cardiac health due to its impact on the heart’s electrical conduction system. This condition disrupts the transmission of electrical signals from the atria to the ventricles, leading to potentially life-threatening complications if left untreated (American Heart Association [AHA], 2020).

Causes of Complete or Third-Degree Heart Block

Complete or third-degree heart block can arise from various factors, each influencing the heart’s electrical pathways differently:

  1. Degenerative Changes: As individuals age, natural degenerative changes within the heart’s electrical system can impair conduction pathways, contributing to heart block (Mayo Clinic, 2022).
  2. Heart Disease: Conditions like coronary artery disease, myocardial infarction (heart attack), and cardiomyopathy can cause structural damage to the heart muscle, affecting its ability to conduct electrical signals effectively (AHA, 2020).
  3. Congenital Heart Defects: Some individuals are born with congenital abnormalities in the heart’s electrical system, predisposing them to heart block later in life (Mayo Clinic, 2022).
  4. Medications: Certain medications, particularly those used to manage arrhythmias or hypertension, can interfere with normal heart conduction, leading to heart block as a potential side effect (Mayo Clinic, 2022).
  5. Inflammatory Conditions: Infections such as myocarditis or inflammatory diseases like rheumatic fever can inflame the heart tissue, disrupting electrical impulses and causing heart block (AHA, 2020).

Symptoms of Complete or Third-Degree Heart Block

The symptoms of complete heart block vary depending on its severity and the individual’s overall health. Common symptoms include fatigue, dizziness or lightheadedness, fainting (syncope), chest pain, and shortness of breath (Mayo Clinic, 2022).

Diagnosis of Complete or Third-Degree Heart Block

Diagnosing complete or third-degree heart block typically involves specialized tests to assess heart function and electrical activity:

Treatment Options for Complete or Third-Degree Heart Block

Treatment strategies for complete or third-degree heart block focus on restoring normal heart rhythm and preventing complications:

Prognosis and Long-Term Outlook

With appropriate treatment, many individuals with complete or third-degree heart block can lead normal lives. Pacemakers effectively manage heart rate and rhythm, allowing patients to resume daily activities with reduced risk of complications associated with untreated heart block (AHA, 2020).


Complete or third-degree heart block requires prompt diagnosis and treatment to prevent serious complications and improve quality of life. By understanding the causes, symptoms, diagnosis, and treatment options discussed in this article, individuals can take proactive steps in managing heart block and maintaining heart health. If you or someone you know experiences symptoms suggestive of heart block, seeking medical attention promptly is crucial for proper evaluation and care.

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American Heart Association. (2020). Heart block (AV block). Retrieved from

Mayo Clinic. (2022). Heart block. Retrieved from

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