EKG stuff Flashcards
What is a holter monitor?
a portable EKG unit that CONTINUOUSLY records heart signal for about a day (25 hrs)
- pt presses button when theres symptoms or when theyre intentionally exercising
reasons to use a holter monitor
- palpitations
- SOP
- syncope
BIG boxes on EKG time
little boxes on EKG time
- .2 seconds = 5mm
- .04 seconds = 1mm
What does the PR interval represent & why is it important
the PAUSE at the AV node
for refractory interval
What does the QT interval represent
the time it takes to depolarize and repolarize the VENTRICLES
Isoelectric Conditions (baseline) should occur what 3 times ?
- after P wave
- After QRS
- After t wave
What does it mean if there is ST elevation? Depression?
Elevation: Myocardial infarction
Depression: Myocardial ischemia
What is the path and vector of depolarization in the heart
- SA node
ATRIA - AV node
PAUSE - Bundle of His
- Bundle branches
APEX - Perkenjie fibres
BASE
Vector must go down and to the L bc more muscle mass on left (towards L ventricle)
What can wandering baseline be due to?
- loose wires
- moving clothes
- poor prep of electrode on skin
60 Cycle interference ???
- produced by wall current
- superimposed on tracing
Normal amplitude for P, QRS, and T wave
-P : upright and symmetrical
- QRS : R is always first upward deflection
- T : upright and symmetrical
Explain what each thing represents :
P wave
PR interval
QRS
ST Wave
T
QT Interval
P wave: produced by atrial depolarization
- PR interval: pause in AV node; time between atrial depolarization and ventricular depolarization
- QRS: ventricular systole/depolarization AND HIDDEN atrial repolarization
- ST Wave: ventricular depolarization/diastole
- T : ventricular repolarization
- QT Interval: time for depolarization and repolarization to occur
What does inverted T wave represent?
Myocardial Ischemia
Pacemaker rates
SA node: 60-100 bpm
AV node: 40-60 bpm
Ventricular cells/Bundle of His: 40-60 bpm
Bradycardia vs tachycardia cause
Bradycardia < 60 ; caused by enhanced SV or BETA blockers, TBI
Tachycardia >100 ; normal w/ exertion
Ectopic Foci
an area in the heart that can generate a depolarization signal
- other than SA or AV
what part of the heart is the workhorse of the heart
bottom L Ventricle
what does a magnitude of > 1/3 QRS complex represent
an old MI
What is R’ (R prime?)
- second upward deflection indicating abnormality when one ventricle depolarizes later than normal
what nerve slows HR below 100bpm?
vagus
How is HR increased?
by decreasing vagal and increasing sympathetic inputs
What is regular rhythm (time and boxes) ? whats the analogy that it looks like?
PR Interval
QRS Complex
PR interval: .1-.2 seconds OR 3-5 small boxes
QRS Complex: .01-.1 seconds 1.5-2.5 small boxes
LOOKS LIKE A PICKET FENCE
Regularly Irregular
EKG not the same every time; there IS a PATTERN
Irregularly Irregular
- what is it usually?
no consistent pattern; changes from one cardiac cycle to the next
- usually A Fib
Sinus Arrhythmia
Cause: increases w/ inspiration
Tx: goes away w/ activity
Sinus Pause
damage to SA node
Cause: infection, infarction, sick sinus syndrome, ischemia
Sinus pause vs Sinus arrest
Sinus pause : <2 sec
Sinus arrest: >2 sec !STOP and REPORT!
Wandering atrial pacemaker
when there is more than one node initiating heart beat
PAC Premature atrial contraction
beats that occus earlier than normal and are generated by ectopic foci in the atria
Cause: stress, nicotine, alcohol, caffine
Atrial Tachycardia
when theres 3+ PACs in a row w/ increased HR
Cause: pH issues, hypoxia
Tx: beta blockers, holding breath, valsalva maneuver
PAT - Paroxysmal Atrial Tachycardia
sudden increase in HR w/ normal looking complexes
Cause: digital toxicity
Atrial Flutter
Multiple depolarization of atria caused by ectopic focus rate >250x/min
Sawtooth pattern with F waves- no p waves
Atrial Fibrillation
no real pacemaker
no p wave
Tx: anticoagulant - warfarin
Artial Issues all have normal ____
QRST complexes
Significant Q represents
previous MI
Escape beat vs repeated beat
Junctional Tachycardia
no p before qrs
- faster than 100
Premature Ventricle Contraction PVC
- wide unbalanced QRS
- occurs when ectopic focus originates from an impulse in one of the ventricles
- VERY SLOW conduction therefore giving large and weird
Psysiological consequences of a PVC (hint: SV AND BP
a weak contraction when BP drops
increased preload and SV
bc frank starling effect
- pvc feels like pause followed by a stronger beat
What to do if you see V FIB
stop and call code
stop and get defib
what to do if you see V Tach
stop pt and see if it resolve
get help if it doesnt
Bigeminy PVC
when every other beat is a PVC
Trigeminy PVC
when every 3rd beat is PVC
Couplet
When 2 pvcs are paired together
Automaticity
altered pacemaker functionC
Conduction:
- blocks
- abnormal propagation of AP
First Degree Block
pr interval longer than .2 sec
- 5 little boxes or 1 big box
depolarizes slowly
Second Degree Block: Mobitz type 1 (Wenckebach)
- AV becomes more refractory w/ beats
- PR interval lengthens
- AV node fails
DROPS QRS
Second Degree Block: Mobitz type 2
- AV node slow to repolarize
- blocks on next beat
- AV node recovers
- 2:1, 3:1 ratio of P:QRS
REGULARLY DROPS QRS
Third Degree Block
no relationship between P and QRS
- separate rates and rhythms for the atria (p waves) and ventricles (QRS)
Bundle Branch Block
one, both or part of one bundle branch conducts slowly
- qrs wider than .12 (3 little boxes)
Wolff Parkinson White
- depolarization of atria and pause at AV node
BUT theres an alternate pathway it takes without pause - causes delta shaped wave
- can cause tachycardia
Atrial PAC
nodial or av PJC
Ventricle:
atrial: weird P wave
ventricle:absent p after qrs or short pr interval
junctional: p wave hidden, t missing
