Diagnostic criteria

  Heart rate < 50/minute.

  P wave is positive in D1 and D2.

  Every P wave is followed by a QRS complex.




Causes of sinus bradycardia

  During sleep

  Medications: beta blockers, verapamil, diltiazem, amiodarone, digoxine, ivabradine, clonidine,

      lithium, pyridostigmine

  Myocardial ischemia or infarction

  Hyperkalemia

  Increased vagal tone

  Athlete's heart

  Hypothyroidism

  Increased intracranial pressure

  Hypothermia

  Advanced age





ECG 1. Sinus bradycardia.

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ECG 2. Sinus bradycardia due to concomitant ingestion of bisoprolol and diltiazem.

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ECG 3. Sinus bradycardia during acute inferior myocardial infarction. The heart rate is approximately 25/minute.
Inferior leads show ST segment elevation.
Immediately after recording of the above ECG, the patient underwent coronary angiography which revealed 99% stenosis of
the proximal Right Coronary Artery (RCA).

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