Rhythm strip findings of nodal ischaemia
ECG leads / veins
Not a lead group but the rhythm consequences of nodal ischaemia. Inferior MI produces sinus bradycardia, sinus arrest, junctional rhythm and Wenckebach or complete heart block with a narrow escape; anterior MI produces bundle branch block progressing to infranodal complete heart block with a wide escape.
Traced from the start
- Right (anterior) aortic sinus
- Left (posterior) aortic sinus and left main stem
- Right coronary arteryLeft circumflex artery
- Sinoatrial nodal artery
- Left anterior descending (anterior interventricular) artery
- Atrioventricular nodal arterySeptal perforating branches of the LAD
- Sinoatrial nodeAtrioventricular node and His bundle
- Rhythm strip findings of nodal ischaemia
Detail
- SA node ischaemia
- Sinus bradycardia, sinus pauses, atrial fibrillation
- AV node ischaemia
- PR prolongation, Mobitz I (Wenckebach), complete heart block with junctional escape 40 to 60/min
- Infranodal (septal) injury
- New RBBB, bifascicular block, Mobitz II, complete heart block with ventricular escape 20 to 40/min
When it goes wrong
Symptomatic bradycardia or nodal AV block in inferior MI
Atropine 600 micrograms IV, transcutaneous pacing if refractory; reperfusion usually restores conduction
Mobitz II or complete heart block in anterior MI
Temporary transvenous pacing without waiting; atropine is ineffective below the node
Practise this structure
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