Test1: week3-4 Flashcards
where is the cardiac cycle measured from?
Start of p wave to the end of T wave
what is a normal length of the QRS complex?
0.08s-0.12s
what is a normal duration of a pr interval?
0.16-0.2s
what would a wide qrs complex indicate?
originates from the ventricles
what does a narrow QRS complex come from?
from the atria
how is ST depression Identified?
S-T segment >0.5mm below the baseline–> indicates electrolyte imbalances ( hypokalemia) and ischemia.
How is S-T elevation identified?
S-T segment >1mm above the baseline indicates MI
What is a normal QT interval?
0.36-0.44s
what is the rate of the SA node?
60-100 bpm
what is the rate of the AV?
40-60bpm
What is the rate of the Bundle of HIS?
40-60bpm
what is the rate of the purkinji fibers?
20-40bpm
how to identify SVT
- narrow complex
- no discernable p waves
- tachy rate at 200-250bpm
- regular rhythm
how to identify PSVT
SVT that Stops and starts
what is Wolf-Parkinson White?
a type of re-entrant SVT caused by an accessory pathway, has a slur on the QRS complex, increasing rate.
What is a sinus pause/arrest?
the SA node fails to make an impulse causing one missed complex followed by a beat.underlying normal rhythm.
Can sinus pause/arrest cause an syncopal episode?
Yes, if there is a significant pause in conduction it can result in reduced blood flow.
what is sinus exit block?
a missed beat caused by conduction disorder ( ex:hyperkalemia)
What is atrial tachycardia?
like sinus tach but originates from the AV node with typical rate <150bpm.
what is PAT
Paroxysmal atrial tachycardia, that originates from one atrial fochi ( consistent p waves)
what is MAT
Multifocal atrial tachycardia where the impulses originate from different areas of the atria ( different p wave morphologies)
- common in COPD/cardiac pt
what is atrial fib?
Disorganized and fast conduction of the atria that is irregularly irregular, no discernable p waves, and narrow complex.
why are afib pt on anticoagulation medication?
they are unable to pass the full vol of blood from atria to ventricle leading to stasis of blood–> clots that can get into circulation.
what rates can atrial conduction cells get up to?
200-250bpm
what is atrial flutter?
originates from 1 atrial fochi that is regular, sawtooth pwaves, with abnormal ratios, it can be fast or slow, narrow complex
What is wap
wondering atrial pacemaker that is the slower version of MAT
- narrow complex, irregular rhythm, different p wave morphology
What is a junctional rhythm?
originates from the av node, none-inverted-retrograde pwaves, pace of av 40-60bpm.
what is accelerated junctional rhythm?
underlying regular rhythm, rates between 60-100bpm, inverted-absent-retrograde pwaves
what is junctional tachycardia?
underlying regular rhythm, absent-retrograde-inverted pwaves, >100bpm,
when the fochi originates from the center of the av node the impulse enters the atria and ventricles _______
simontaneously
when a fochi enters the atria at the top of the AV node the impulse enters the atria _____ and the ventricles ________
artia–> first
Ventricles –> second
Pacemaker near the bottom of the AV node will enter the ventricles ____ and the atria _____
ventricles –> 1st
atria–> 2nd
what is a PAC?
premature atrial complex, originates from a different atria fochi than the SA node, junctional pwave, preceds next beat, underlying regular rhythm
what is a PJC?
pre-junctional complex, originates from the AV junction, occurs before next beat and followed by a compensatory pause, junctional pwaves, narrow complex and normal PR interval
what are the 2 types of artifact?
somatic tremor: skeletal muscle
60 cycle interference: near by electrical appliances
what is Idoventricular rhythm?
when the all other nodes fail so the ventrile take over. rate of the ventricles ( 20-40bpm), wide complex, no p waves, regular
what is accelerated idioventricular rhythm?
idioventricular rhythm at 50-200bpm
what is a PVC?
Premature ventricular complex, usually associated with svt, junctional p waves, big “ugly” qrs, can be unifocal or multifocal, proceds next expected beat.
What is a PVC r on t?
when a PVC occurs on the relative refractory period—> sends heart into vf-vt-asystole
what is torsade des pointes?
Vf and vt twisting down the paper, rates of 200-250bpm, occurs when multiple ventricular sites are firing
what is refractory vf?
constant vf even after 3 shocks
what is ventricular fibrillation?
unorganized and rapid quivering of the ventricles, no discernable pwaves, qrs, or t waves.
what characterizes a 1st degree heart block?
Constant PR interval, 1:1 p:QRS, PR interval>0.20s (prolonged),
“if R is far from P then its….”
1st degree
what is another name for snd degree type 1?
mobitz 1 or wenkebach 1
what is 2nd degree block type 1 characterized by?
variable Pr interval, variable P:qrs ratio, Pr gradual increases until a beat is dropped,
what is second degree type 2 characterized by?
mobitz2/wenkebach2, Constant PR interval, variable P:QRS ratio, dropped beat!
If some p waves don’t get through then you have….
mobitz 2
What is 3rd degree block characterized by?
Complete av dissociation, varied pr intetval, varied p:qrs ratio, P waves appear to be “marching” through, bradycardic
If the P’s don’t agree then you have…
3rd degree
how does a demand pacemaker work?
When the natural heart rate decreases to a threshold of 60bpm then it takes over pacing
What is a ventricular pacemaker?
Identified by a verticle line before the QRS, initiated when natural conduction is slowed to its threshold
What is a dual chamber or atrio-ventricular pacemaker?
identified by a linear line before P wave and one before qrs. Innervates conduction when the natural pace its the slowed threshold
What are some complications of pacemakers?
Runaway pacemaker, dislodged node, fractured wire etc.
