Sinoatrial node
Territory
The pacemaker, lying subepicardially at the junction of the superior vena cava and right atrium near the top of the crista terminalis.
Traced from the start
Detail
- Supplied by
- SA nodal artery (RCA 60%, circumflex 40%)
- On ischaemia
- Sinus bradycardia, sinus pauses, junctional escape, atrial fibrillation
When it goes wrong
Sinus node ischaemia in inferior MI
Sinus bradycardia with hypotension; treat with atropine, usually settles with reperfusion
Practise this structure
2 questions in the bank tagged Cardiac Conduction.
A 24-year-old man presents with two hours of palpitations. He is alert, has no chest pain, and his blood pressure is 124/76 mmHg. The radial pulse is regular at…
Foundations · common
A 46-year-old labourer is freed after six hours trapped beneath a collapsed brick wall. Both thighs are tense, swollen and tender, and he cannot move his toes.…
Foundations · middle twist