Cardiac Monitors Flashcards
Name 3 bipolar leads
I, II, III
Name 3 limb leads
aVF, aVR, aVL
causes of R axis deviation
COPD, acute bronchospasm, Cor pulmonale, PHTN, PE
Causes of L axis deviation
chronic HTN, LBBB, AS, AI, MR
What reflex may initiate sinus arrhythmia?
Bainbridge. increased venous return stretches the right atrium and SA node causing the HR to increase
WPW is a/w?
atrial-ventricular reentry. (occurs when accessory pathway joins the atrium to the ventricle- Kent’s bundle)
What are 2 ways to disrupt reentry circuit?
- slow conduction velocity through circuit
- increase refractory period of the cells at the location of unidirectional block
What is the most common cause of tachyarrhythmias?
reentry pathways
How can ischemia cause a reentry pathway?
conduction velocity through the affected region is too slow
How can Epi cause a reentry pathway?
It shorted the duration of the refractory period
Drugs to avoid with antidromic AVNRT
adenosine, digoxin, CCBs, BBs, & lidocaine
What is the tx of choice for a fib in WPW?
Procainamide bc it increases the refractory period in the accessory pathway
What is the most common tachyarrhythmia a/w WPW?
orthodromic AV nodal reentry tachycardia (90%)
conditions that prolong QT interval
hypokalemia
hypomagnesemia
methadone
droperidol
ondansetron
amio
hypertrophic CM
bradycardia
what are 2 immediate tx for torsades de pointes
Mag & cardiac pacing
List 5 pathophysiologic conditions that can cause failure to capture
hypokalemia
hyperkalemia
hypocapnia
hypothermia
MI
what ecg change is a/w intracranial hemorrhage?
peaked T waves
Where does atrial repolarization occur on the ecg?
QRS
What is the tx for BB overdose?
glucagon 50-70 mcg/kg q 3-5 min followed by 2-10mg/hr infusion
If lead I is pointing up and aVF is pointing up, what axis does it have?
Normal (2 thumbs up)
If lead I is pointing down and aVF is point up, what axis does it have?
Right axis deviation (Reaching towards each other)
If lead I is pointing down and aVF is pointing down, what axis does it have?
Extreme right axis deviation (2 thumbs down)
If lead I is pointing up and aVF is pointing down, what axis does it have?
Left axis deviation (Leaving each other)
