Atrial Rhythms Flashcards
where do atrial dysrhythmias originate?
from atria tissue NOT the SA node
what are the atrial rhythms?
premature atrial contractions, atrial tachycardia, aflutter and afib
what are PACs?
premature atrial contractions that are single ectopic beats originating from atrial tissue
what happens in a PAC?
the atria contract earlier than expected
what is a PAC also called?
an ectopic focus b/c site of impulse formation is outside of the normal conduction system and acts as a pacemaker
when does a PAC occur?
when an ectopic focus fires an impulse faster than the SA node
what rate can atrial tissue fire at?
250-300x/min
what would the rhythm be for a rhythm with a PAC?
irregular d/t PAC or underlying regular with ___# of PACs
what is different about a PAC on a waveform?
the P wave will be different; avoid using for calculating atrial rate
what are causes of PACs?
- simulants (alcohol, caffeine, tobacco)
- hypoxia
- electrolyte imbalances
- cardiac ischemia
- cardiomyopathy
what are implications to O2 supply and demand with PACs?
- in healthy individuals there are no significant effects
- if there are frequent PACS in the context of underlying heart disease, the pt’s CO and O2 supply will decrease and HR will increase which can lead to aflutter or afib
- arterial BP drops when there is a PAC d/t drop in CO and SV
interventions for PAC
check pt (ABCs). check electrolytes and correct if needed. call doctor if concerned
what happens in atrial tachycardia?
irritable atrial ectopic focus fires rapidly and causes atria to contract rapidly (150-200x/min)
what is different about the ecg strip in atrial tachycardia?
you will not be able to see the P waves, and therefore cannot calculate an atrial rate or PR interval
what are the oxygen supply and demand implications for atrial tachycardia?
increased HR causes:
1) increased myocardial/O2 demand leading to ischemia and tissue damage
2) decreased VFT = decreased CO
3) decreased coronary perfusion time = decreased contractility
