A new Sinus Bradycardia Section has been added to the ECG Analysis Module on www.richacls.com. Below are some of the Key Learning Points (KLP)
Sinus Bradycardia: Introduction
Any rhythm less than 60 beats per minute can be labeled as bradycardia or called bradycardic.
The rule-of-ten rate measuring tool becomes less accurate with slow heart rates.
Sinus Bradycardia: Characteristics
- Since Sinus bradycardia is generated by the sinus node, it has the same characteristics as sinus rhythm except for the rate.
- The rhythm is regular.
- The heart rate is below 60 beats per minute.
- There is a P wave before each QRS complex.
- •P Waves will be the same shape.
Sinus Bradycardia: Normal-Abnormal
It is not uncommon to see heart rates below 60 beats per minute in athletes and individuals with good cardiac health
Sinus bradycardia is abnormal or symptomatic when the slow heart rate causes the cardiac output to drop below the body’s circulatory requirements, evidenced by low blood pressure and or cardiac shock symptoms; cool extremities, moist skin etc.
There are various situations which can cause symptomatic sinus bradycardia.
- Myocardial infarction
- Disease of the SA node
- Vagal stimulation
- Medications

