arrhythmias involving the AV node Flashcards
what are the main causes of AVN conduction disease? 8
- ageing process
- acute MI
- myocarditis
- infiltrative disease- amyloid
- drugs
- calcific aortic valve disease
- post-aortic valve surgery
- genetic
name 2 drugs which may cause AVN conduction disease
b blockers
Ca channel blockers
name some genetic conditions that can cause AVN conduction disease?
lenegre’s disease
myotonic dystrophy
what are the ECG features of 1st degree block?
prolongation of the PR interval >0.2
what is the treatment for 1st degree block?
no treatment just long term follow up
what are the ECG features of 2nd degree mobitz type 1 block?
progressive lengthening of the PR interval, eventually resulting in a dropped beat
what are the ECG features of 2nd degree mobitz type 2 block?
Usually 2:1, or 3:1, but may be variable
what treatment is indicated for mobitz type 2
permanent pacing
what are the ECG features of 3rd degree block?
the atria and ventricles generate impuklses independently of each other
what happens to the heart rat in 3rd degree block?
it stays regular
what may happen to the ventricles in 3rd degree block as a result of complete block which is very dangerous?
they may sometimes go into standstill - this is asystole and the patient does not survive
why do many people not go into asystole in 3rd degree block?
most people have automaticity in the ventricles so there may be a escape rhythm
