CARDIAC ARRHYTMIAS Flashcards
normal PR segment
40-60
What is the origination of U waves?
depolarization of Purkinje fiber
normal PR interval
0.12-0.20 sec
normal QRS
<0.12
SA node discharge
60-100 / min
AV node discharge
40-60 /min
ventricular tissue discharge
20-40 /min
in SINUS ARRHYTMIA
rate INCREASE AS………………….
the patient breathes in
in SINUS ARRHYTMIA
rate DECREASE as ……………………….
breathes out
RATE is usually …………………… in SINUS ARRHYTMIA
60-100(MAYBE SLOWER)
what is SINUS ARREST?
stop of sinus rhythm,new rhythm starts
what is SINUS PAUSE ?
one dropped beat is a sinus pause
Premature Atrial Contraction (PAC)
- One P-wave for every QRS(P-wave may have different morphology on ectopic beat, but it will !!!!! be present)
- Single ectopic beat will disrupt regularity of
underlying rhythm - Rate will depend on underlying rhythm
- Underlying rhythm must be identified
- Classified as rare, occasional, or frequent
PAC’s based on frequency
Atrial Fibrillation
– No discernable p-waves(The atria are not depolarizing effectively, but fibrillating)
_Rhythm is grossly irregular
_If the heart rate is <100 it is considered controlled a-fib, if >100 it is considered to have a “rapid ventricular response”
_– AV node acts as a “filter
atrial tachycardia
140-250 Heart rate
atrial flutter
250-400
_more than one p wave (sawtooth)
3:1 p wave for each QRS
junctional Rhythms
- Rhythms that originate at the AV junction
- Junctional rhythms do not have characteristic p-waves.
Premature Junctional Contraction (PJC)
– P-wave can come before or after the QRS
complex, or it may lost in the QRS complex
* If visible, the p-wave will be inverted
– Rhythm will be irregular due to single ectopic beat
– Heart rate will depend on underlying rhythm
– Underlying rhythm must be identified
– Classify as rare, occasional, or frequent PJC based on frequency
Accelerated Junctional Rhythm
_rhythm is regular
_HR 60-100 / min
