Rapid EKG III Flashcards
premature atrial beat
irritable atrial foci
-produces P’ wave earlier than expected
reset rhythm
SA node will pace one cycle length after a premature beat
-bc dominant center depolarized by premature beat
reality - first cycle after PAB lengthened - due to PS on SA node
premature atrial beat with aberrant ventricular conduction
widened QRS
-one bundle branch is not completely repolarized when PAB sends signal
non-conducted premature atrial beat
has no QRS complex following
-will see reset pacing
atrial bigeminy
auto foci fires PAB after each cycle
- couples to end of normal cycle
- process repeats
- see a couplet
atrial trigeminy
auto foci fires PAB after each two cycles
-group beatings in patterns
premature junctional beat
irritable junctional foci firesa
- right bundle branch - more likely to be in refractory
- can lead to aberrant ventricular conduction
- may see inverted P’ wave
- before, during, after QRS complex
- retrograde atrial depolarization
aberrant ventricular conduction
- signal fired before both bundle branches are repolarized
- results in widened QRS
-right bundle branch - slower to recover
junctional bigeminy
premature junctional beat with each sinus cycle
-see absent or inverted P’
junctional trigeminy
premature junctional beat coupled with every two sinus cycles
-see absent or inverted P’
irritable ventricular
low O2
low K
pathology - mitral valve prolapse, stretch, myocarditis
premature ventricular contraction
sudden wide QRS complex
-opposite polarity of the sinus QRS
**often with hypoxia
compensatory pause
not resetting
-but it is the repolarization of ventricles
interpolated PVC
sandwiched between two normal beats
-no pause and no rhythm disturbance
slender QRS
due to simulataneous depolarization of both ventricles
pathologic PVCs
six or more per minute
ventricle bigeminy
PVC couples to single cycle
ventricle trigeminy
PVC couples to two cycles
ventricle quadrigeminy
PVC couples to three cycles
ventricular parasystole
ventricular foci with entrance block
- can’t be overdrive suppressed
- paces at its own rate
-see pacing at its own rate with PVC
very irritable ventricular foci
can emit consecutive stimuli
run of three or more PVCs
ventricular tachycardia
sustained VT
sustained ventricular tachycardia
-VT lasts longer than 30 seconds
runs of PVCs
multifocal PVCs
severe cardiac hypoxia
- distinct QRS complexes
- multiple irritable ventricle foci
barlow syndrome
mitral valve prolapse
-can cause PVCs
floppy valve that billows into left atrium during ventricular systole
more in females
- slender, chest deformity
- dizzy spells
- anxiety prone
- after age 20
theory - chordae tension from valve prolapse stretches ventricular foci
R on T phenomenon
PVC falls on T wave
- hypoxia or hypokalemia
- dangerous
-extends purkinje repolarization further
paroxysmal tachycardia
rate 150-250
flutter
rate 250-350
fibrillation
rate 350-450
paroxysmal tachycardia
sudden irritable foci paces rapidly
-atrial, junctional, ventricular
epinephrine
irritable atrial/junctional foci
hypoxia and low K
ventricular foci irritable
paroxysmal atrial tachycardia
rapid rate 150-250
- irritable atrial foci
- P’ waves not like sinus
PAT with AV block
more than one P’ for every QRS
- digitalis excess or toxicity
- 2:1 ratio of P’:QRS
digitalis
- can make atrial foci irritable
- also inhibits AV node
paroxysmal junctional tachycardia
- rapid rate 150-250
- irritable junction foci
- lacking P’ wave
- or P’ before, during, after QRS
may cause aberrant ventricular contraction
-somewhat widened QRS
AV nodal reentry tachycardia
continuous reentry circuit develops
-AV node and lower atria
-foci - near coronary sinus
supraventricular tachycardia
irritable foci in both atrial and junctional paroxysmal tachycardia
-because above ventricles
-Tx is similar - umbrella term is used
paroxysmal ventricular tachycardia
- rapid rate 150-250
- sudden irritable ventricular foci
- enormous rapid PVCs
- SA node can still be pacing atria
- AV dissociation
AV dissociation
SA depolarization to atria
- finds ventricular receptive
- produces normal appearing QRS
- capture beat***
- among the VT
also - atrial depolarization -finds receptive AV node
- ventricular depolarization only goes so far - meets ventricular depolarization from ventricular foci
- fusion beat***
confirm diagnosis of VT
confirm diagnosis of VT
capture and fusion beats