Cardiac Arrhythmias Flashcards
(21 cards)
tachycardia
fast HR
bradycardia
slow HR
supraventricular arrhythmia
involves atrium or AV node
ventricular arrhythmia
involves His-Purkinje system or ventricles
Arrythmias result from
-alterations of impulse formation, impulse conduction, or both
AP of pacemaker cell (SA node)
What usually sets the HR?
SA node
latent pacemakers
- aka ectopic pacemakers
- have potential to act as pacemakers if necessary (if SA node slows or fails to fire or if conduction abnormalities block normal wave of depol from reaching them)
- AV node and bundle of His
overdrive suppression
cell pop w/ fastest intrinsic rhythm preempts other automatic cells from spontaneously firing and also directly suppresses their automaticity
p wave
atrial depolarization
p-q segment
AV node and His-Purkinje system activation
QRS
ventricular depol
QRS duration
time required for ventricular depolarization
normal QRS duration
<0.12s
What can cause widened QRS?
bundle branch block
two causes of wide QRS (>0.12s)
* supraventricular beat conducted with aberrancy (bundle branch block)
* ventricular tachycardia
normal sinus rhythm
60-100bpm
sinus tachycardia
>100 bpm
sinus bradycardia
<60bpm
determining HR with big box technique
300, 150, 100, 75, 60, 50
systematic approach to ECG interpretation
- What am I looking at?
- single lead rhythm strip
- simultaneous recording of 2 or more ECG leads
- 12 lead ECG - What is HR?
- What is hapening in the atria?
- What is happening in the ventricles?
- Are atrial and ventricular activity related?
