Bradycardia (< 60 bpm)

CLINICAL DIAGNOSTIC MANUAL

Bradycardia, defined as a heart rate below 60 beats per minute (bpm), can be a challenging clinical phenomenon, with various causes potentially at play. Understanding these causes is crucial for accurate diagnosis and effective management. Below, we explore some of the most common causes of bradycardia and how to identify them.

Cause	Symptoms and Signs	Diagnostic Tests
Athlete’s Heart	Heart adaptation to training	Minimal symptoms, physiological bradycardia
Medications	Side effects of certain medications	Fatigue, dizziness, syncope
Sinoatrial Node Disease	Sinus node dysfunction	Dizziness, weakness, syncope
Ventricular or Supraventricular Bigeminy	Arrhythmias such as bigeminy	Palpitations, dizziness
Acute Myocardial Infarction	Acute myocardial infarction	Chest pain, fatigue, sweating
Hypothyroidism	Decreased thyroid function	Fatigue, cold intolerance
Hypothermia	Decrease in body temperature	Confusion, shivering, cold skin
Severe Electrolyte Imbalances	Electrolyte disturbances, especially low potassium levels	Muscle weakness, palpitations