Therapeutic target
Avoidance of complications (e.g., switching to a different heart rhythm).
Therapy recommendations
- Emergency: atropine (parasympatholytic) for severe bradycardia (heart rate too slow: < 40-50 beats per minute).
- Sinuatrial block is rarely an indication for drug therapy; symptomatic forms of sinuatrial block should be treated by pacing.
- Note on the three degrees of severity of SA block:
- 1st degree sinuatrial block is usually asymptomatic (without symptoms)
- SA block 2nd degree results in intermittent failure of conduction of sinus node impulses
- SA block 3rd degree leads to the fact that the sinus node impulses are not transmitted to the atrial myocardium at all; as a result, substitute rhythms (e.g., AV nodal rhythm) occur.
