Blonder - AV Block Flashcards
Is a 1st degree AV block rate dependent or independent?
Rate dependent
What is the physiologic significance of the prolongation of the PR interval in 1st degree AV block?
Loss of atrial kick effect for ventricular filling
Major causes of AV Block
Increased vagal tone
Fibrosis and sclerosis of conduction system
Ischemic heart disease
Cardiomyopathy/myocarditis
Congenital heart disease
What major classes of drugs can cause AV blockade?
Ca++Ch Blockers, esp the non-DHPs like verapamil and diltiazem
β-blockers
What is the difference between 3rd degree AV block and AV dissociation?
In 3rd degree AV block, atria and ventricles are each going at their own rate and V-rate is slow
In AV dissociation, atrial conduction firing at its intrinisc rate, but V-rate is very fast (vtach) and overdriving the atria
What is syncope with a 3rd degree AV block called?
Stokes-Adams attack