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EKG rhythms questions and answers
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Normal Sinus Rhythm โโ 60 - 100 bpm
all complexes normal and evenly spaced (P, QRS, T)
Sinus Arrest โโ- SA node doesn't fire
- notice absence of P-wave for a complete cycle (a missed cycle)
Sinus arrhythmia โโall complexes normal but rhythmically irreg
- normal finding (esp in young pts) that has to do with breathing (rate: inhale-increase, exhale- decrease)
Sinus Bradycardia โโ<
normal sinus rhythm
Sinus Tachycardia โโ>100 (100-150)
normal sinus rhythm
Wandering atrial pacemaker โโHint: try never to pick this
- impulse originate from varying points in atria
- variation in P wave contour, PR-I, PP-I and thus RR-I
P wave vs T wave โโP generally smaller than T
MAT (multifocal atrial tachy) โโ- impulse originates at diff places in atria so P waves diff and
intervals might not be consistent
Atrial Fibrillation โโA: 350-450 (atria quivering)
- irreg-irreg rhythm (R-RI=irreg)
unsure/no P-wave (non-distinguishable)
- irreg rhythm BUT reg QRS!
Danger: increase the risk of thromboemoblic events don't convert unless occurring less than 48 hrs, if don't know pt need to be put on thrombolytics)
Atrial Flutter โโA: 250- 350
Premature junctional contractions (PJC) โโ- premature slightly widened QRS
- +/- inverted P', before or after QRS, sometimes disappears w/in QRS
Premature atrial contractions (PAC's) โโ- originates suddenly in irritable atrial foci
- P' is earlier than expected and diff shape than P (often have a pause following PAC)
- can occur in Bigeminy, Trigeminy, Quadgeminy pattern
Supraventricular Tachycardia (SVT)
aka
Paroxysmal atrial tachycardia (PAT) โโ150-250 "sudden rapid heart rate"
- an irritable atrial focus discharging
- very fast and EVEN!
- +/- inverted P waves
- P often overlaps prior T wave
First-degree AV block โโ- PRI >5 boxes/.20 sec
(consistent but long)
- normally get bradycardia here
Second-degree block: Mobitz Type I Wenckebach) โโ"walk it back"
- PRI gradually lengthens then drops QRS "grouping and then a miss"
- typically pattern exists
(constant P-P interval, QRS is what is moving back)
- not really serious or dangerous
Second-degree AV block: Mobitz Type II โโ- normal PRI then sudden drop of QRS
- P wave doesn't always produce QRS
- P-R interval is constant (diff from 3rd degree)
- no hint just drops out -> is serious and dangerous pt needs tx!
- tend to be every other, so drops HR by 1/2) --> def bradycardia (rate=40bpm)
Third-degree AV block (complete block) โโrate around 40's
- no relationship b/t P waves and QRS complexes (QRS slower than P rate)
- P-P reg (atrial reg) & R-R reg (vent reg)
but NOT connected (i.e P-R inconsistent)
- no P waves (from vent foci)
- Wide QRS
(serious, death like rhythm)
- called "dying heart" rhythm...occasional ventric beat b4 death (asystole)
Accelerated idioventricular rhythm (AIVR) โโ40-
- occur in short burst, usually following MI
- mostly asx with no progression to vtach / vfib
Ventricular tachycardia โโ150-250 (>120 from onysko)
- ventricle irritated and moving fast
- rapid, bizarre, wide QRS complexes
- 1 large QRS after another!
(in vtach pt may not have pulse)
Ventricular Flutter โโ250-
- smooth sine-waves w/ similar amp
- can lead to deadly arryth
goes right into vfib
Tosades de Pointes โโFlutter 250-
- type of vtach, can lead to vfib
- ribbon like fashion (hallmark: up and downward deflection of QRS)
- d.t hypomagnesium
Ventricular Fibrillation โโ350-
- "chaotic"
- mult vent foci rapidly discharging -> erratic vent rhythm
- no identifiable waves
- RESPOND IMMEDIATELY!
- no pulse or perfusion, pt=dead
R atrial hypertrophy โโtall P waves! (in lead II, III, and aVF)
cause: pulm HTN, COPD, Pulm emboli
A block in the Bundle Branch produces a delay in depol of the ventricle that it supplies
(note: can't read ischemia b/c BBB distort this)
if have L & R BBB = complete block
R Bundle Branch Block โโ- wide QRS >3 boxes (0.12)
- V1/V2 "bunny ears" (2-R waves)
(V1/2/3 all up)
- common, doesn't have much path assoc
L Bundle Branch Block โโ- wide QRS >3 boxes (0.12)
- V5/V6 "bunny ears" (2-R waves)
(V1/2/3 all down)
- not as common, more patho
Myocardial Infarction (MI) โโIschemia: inverted Twave
Injury: ST seg elevation
Necrosis: Q wave present
- area of infarct doesn't conduct electrical activity
- infarction=cell death
(A MI (heart attack is) when blood vessels that supply blood to the heart are blocked, preventing enough oxygen from getting to the heart. The heart muscle dies or becomes permanently damaged)
Ischemia โโ- T wave inversion
- Ischemia is caused by a decrease in oxygen to the myocardial tissue (hypoxia/diminished blood supply)
- can still save heart cells/reverse
Injury โโST segment elevation (a sign of acute injury going on presently) (look for sad face)
- Injury indicates the acuteness of an infarct (acute or recent)
- occlusion of circumflex artery
Posterior wall โโsince no post lead look in V1 for unusually large R wave
- occlusion of right coronary artery
Angina pectoris โโ...
Unstable angina โโ...
Digitalis Effect โโ- shortened QT interval
- characteristic down-sloping ST depression (SCOOPING ST seg)
Hypercalcemia โโShort/absent QT segment
(tooo healthy --> short QT (skinny))
Hypocalcemia โโ(not healthy (not taking vit like Ca++) so look like a hipo which is large ->
long QT)
Hyperkalemia โโtall, peaked and narrow T
severe --> flattening of P wave, wide QRS, and tall T='sine wave'
Hypokalemia โโ- flat T present
- depressed ST seg
- U wave to prominent U wave
Lown-Ganong-Levine Syndrome โโAV node by passed, so short PRI
P adjacent to QRS
Pacemakers โโpacemaker spike (may be small; sometimes missed)
- not supraventricular so wide QRS
Pericarditis โโST segment elevated in ALL leads
T wave: may be elevated off the baseline
- Lup/Rdown = Left axis deviation
- Rup/Ldown = Right axis deviation
- Specific axis degrees: determine type of deviation, choose most iso-electric line and go to that line on the circle chart. Go 90 degrees into the good quadrant (the one you know you're in) and that will tell you the exact degrees.
Axis pic โโ
Wide QRS โโVtach, PVC, 3o AV block, BBB
Rate 40's โโ3o AV block, 2o AV block type II, or ventricular rhythm
