Cardiac Flashcards
1st degree HB: AV node conduction
Prolonged but intact
ECG for 1st degree HB
Prolonged PR consistently, otherwise regular
What HB can be treated with atropine
First, Second type 1, block must be above bundle of his
2nd degree HB
One or more but not all sinus impulses blocked
2nd degree HB type I (site of dispruption
AV node
PR interval: 2nd degree HB type 1
lengthens until lost in QRS or blocked impulse
Type II 2nd degree HB site of disruption
AV node or lower
PR interval in type II 2nd degree HB
constant except when blocked. Some P waves with no QRS
2:1 2nd degree HB
2 p waves for every QRS
Third degree HB
Complete block with no conduction
Rhythm in 3rd degree HB
Junctional or Ventricular escape rhythm
P wave and QRS in 3rd degree HB
have no relationship, independent of each other, at rates of pacing cells
Tx for 3rd degree HB
Pacing, Dopamine, E
S/S bradycardia (5)
hypotension Alt Mental status Shock Ischemic chest pain Acute HF
Tx for bradycardia
Pacing, atropine
Bradycardia on CO
Decreased HR = Decreased CO = decreased perfusion
Tachycardia on CO
inc O2 demands increase HR
Equation for CO
HRxSV
SV
amount of blood ejected with each contraction
what is HR determined by
ANS/PNS/SNS
what HR decreases CO
> 200
3 components of SV
Preload
Afterload
Contractility
Preload
Blood volume returning to heart
more preload = ___ SV
more
what affects preload
venous return
Afterload
Opposition of blood leaving heart
more afterload = ___ SV
less
What does angiotension do
Vasoconstriction
purpose of angiotension inhibitor
decrease BP through vasodilation, reduce Na/water retention
effect of calcium on heart muscle
decreases contractility
purpose of Ca channel blockers
slow conduction to increase contractility
How do vasodilators decrease CO
decrease cardiac workload so decreased HR/CO
How do diuretics work
block Na absorption
Rhythms to cardiovert
Atrial tachycardia SVT Aflutter Afib VTach with pulse
Rhythms for Defib
Vtach no pulse
Vfib
Rhythms that need pacing
Sinus arrest Junctional escape Ventricular escape AV block Asystole