Arrhythmia is a disorder in which the heart beats irregularly. It may be too slow or too fast.
Bradycardia is having a heart rate of <50 beats/minute that may not affect the hemodynamic status of some patients.
Clinically significant bradycardia is having a heart rate that is inadequate for the patient's current condition and may not be able to support life.
Tachycardia is having serious signs and symptoms that are often demonstrated at ventricular rates of >150 beats/minute.
Signs and symptoms related to rapid heart rate are altered sensorium, angina, shortness of breath, myocardial infarction, hypotension and other signs of shock (eg cold clammy skin, low urine output), heart failure or pulmonary congestion.


  • Arrhythmias are disturbances in the heart rhythm
  • May either be slower heart rate (bradycardia) or faster heart rate (tachycardia)



  • HR <50 beats/min (bpm)
  • May not affect hemodynamic status of some patients

Clinically Significant Bradycardia

  • HR is inadequate for the patient’s current condition & may be unable to support life

Contributing factors that should be identified & treated:

  • Hypovolemia
  • Hypoxia
  • Acidosis
  • Electrolyte imbalance
  • Hypoglycemia
  • Hypothermia
  • Toxins
  • Cardiac tamponade
  • Tension pneumothorax
  • Coronary/pulmonary thrombosis
  • Increased intracranial pressure (eg in trauma)

Serious signs & symptoms are often demonstrated at ventricular rates >150 bpm
Signs & symptoms related to rapid HR:

  • Altered sensorium
  • Angina
  • Hypotension
  • Shortness of breath (SOB)
  • MI
  • Other signs of shock (eg cold clammy skin, low urine output), heart failure (HF) or pulmonary congestion
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