cariophysiology EKG rhythms... not blocks Flashcards
(42 cards)
sinus rhythm heart rate
60-100
sinus arrhythmia: cause
ANS changes pacing upon respiration.. its normal
three types of atrial irregular rhythms
wandering pacemaker
multifocal atrial tachycardia
atrial fibrillation
wandering pacemaker characteristics - 4
irregular rhythm cagegory
- P wave shape changes
- atrial rate is less than 100
- irregular ventricular rhythm
multifocal atrial tachycardia characteristics - 4
irregular rhythm category
- p wave shape changes
- atrial rate is over 100
- irregular ventricular rhythm
atrial fibrillation characteristics - 3
irregular rhythm categorm
- continuous chaotic atrial spikes
- irregular ventricular rhythm
escape rhythm =
automaticity focus escapes overdrive suppression and PACES at its intrinsic rate
escape beat
automaticity focus TRANSIENTLY escapes overdrive suppression to emit ONE BEAT
atrial escape rhythm characteristics - 3
- normal sinus rhythm then sinus arrest
- the escape rhythm has a different P shape
- new pacing at 60-80 bpm
junctional escape rhythm characteristics - 4
- normal sinus rhythm then sinus arrest
- NO P wave, OR NEGATIVE P wave because this pacing is from AV node
- aka idiojunctional rhythm
- new pace is 40-60bpm
ventricular escape rhythm characteristics - 5
- normal sinus rhythm then sinus arrest
- regularly spaced P waves, but they don’t make QRS
- wide QRS because
- aka idioventricular rhythm
- new pace is 20-40 bpm
atrial escape beat characteristics
same as atrial escape rhythm, but it only happens for one beat because the SA node misses a cycle
AV junctional escape beat
same as juncitonal escape rhytm but it only happens for one beat
ventricular escape beat
same idea as ventricular escape beat EXCEPT….
this happens when both the SA node and the AV node are suppressed (usually by parasympathetics)
when it escapes, the QRS is HUUUUGGGEEE
premature atrial beat characteristics - 4
- premature P wave (because its irritable)
- therefore, prematue QRS
- the premature wave is from an ATRIAL focus, so the P wave looks different from normal
- premature beat resets the system so the subsequent beats line up with the premature one
what sometimes happens with a premature atrial beat
sometimes, the ventricle isn’t totally REpolarized from the last beat so its wide. we call this “aberrant ventricular conduction”. the wide QRS is ONLY for the premature beat
nonconducted premature atrial beat - 3
- the SA node paces, but the AV node decides its not ready yet, so you get NO QRS and T
- the SA node paced, so its STILL the boss
- this looks dangerous (like a block) but is not
atrial bigeminy
when a premature atrial beat keeps tagging along on the end of a normal beat
premature junctional beat
- irritable AV junction fires prematuely
- sometimes makes the P wave negative
- can get a squggly QRST if one of the bundle branches is still trying repolarize
- this is different from ventricular escape because its NOT WIDE
- this usually resets the SA node via retrograde atrial depolarization
AV (junctional) bigeminy
when one premature junctional beat keeps tagging along the end of a normal beat
what causes a juncitonal focus irritable
low oxygen
low potassium
pathology
cocaine
examples of low oxygen that causes junctional focus irritability
airway obstruction
air with poor O2
poor oxygenation in lungs (pneumothorax or embolus)
poor coronary blood supply
example of pathology that causs junctional focus irritability
mitral valve prolapse, stretch, myocarditis
what should you know about cocaine and hearts
- it can make either ATRIAL OR JUNCTIONAL foci irritable
- can cause a coronary spasm…. hypoxic heart in addition to irritable heart
- thats not really a great combo.