Bradycardias
Bradycardia is defined as a heart rate of below 60BPM in adults.
They can be classified based on the QRS complex (narrow or wide), presence and morphology of P waves, and the relationship between the P waves and QRS complexes.
- By itself, bradycardia shows no increased risk for mortality
- In patients with syncope or weakness, atropine can be used to reduce the vagal tone, and a pacemaker therapy can be a permenant solution.
Types
- Sinus bradycardia
- SA pause and arrest
- SA block
- Sick sinus syndrome
- AV block
Sinus bradycardia
- Regularly sinus rhythm but below 60BPM; clinically important when <45BPM.
- Physiological in many cases, can be seen during deep sleep and in athletes.
- Other causes include ischemia, antiarrhythmic drugs, increased vagal tone, and sick sinus syndrome.