Med-Surg 3 Exam Notes – Comprehensive Study Guide, Flashcards &
NCLEX-Style Questions – 100% Toetsgericht
LAATST BIJGEWERKT 2025
Dysrhythmias are a disorder of the
conduction of electrical impulse within the heart
irregularities cause disturbances in
Heart rate
heart rhythm
both
dysrythmias can cause __ effect
hemodynamic
dysrhytmias are diagnosed by __ & named according to
ECG
site/origin
SA node firing rate vs AV junction, node, bundle of his firing rate
SA: 60-100 bpm
AV: 40-60 bpm
purkinje network firing rate
20-40 bpm (intrinsic)
electrical stimulation vs. mechanical stimulation
electrical = depolarization
mechanical = systole
electrical relaxation vs. mechanical relaxation
repolarization
diastole
sympathetic nervous system stimulates
incr. in HR, conduction thru AV node, myocardial contraction
(pos. chronotropy, dromotropy, inotropy)
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parasympathetic nervous sytem stimulates
reduce HR, AV conduction, myocardial contraction
EKG rhythm strip analysis info
HR
rhythm
impulse conduction time intervals
(NOT pumping action, BP, C.O.)
see pt laying on the floor, 1st thing you do
shake pt to see if they wake up
p wave shows & length
atrial depolarization
<0.11 sec
PR interval length
0.12-20 sec (3-5 lil boxes)
QRS complex
ventricular depolarization
(<0.12 sec)
pt comes in with chest/upper ab pain what do you do
ECG within 5-10 min
ST segment represents
early ventricular repolarization
-isoelectric
-flat
(look to see if it elevates/depresses)
T wave represents
ventricular repolarization (resting phase)
peaked t wave suggests & protocol
=hyperkalemia
-labs for potassium, BUN, Cr