ECG Flashcards
Limb lead reversal
negative p-wave, qrs and twave in lead 1
Low voltage
def
<5mm Limb leads
<10mm in ALL precordial leads
Hypocalcemia
prolonged QT
because of lengthened flat ST segment without change in duration or morphology of T wave
Prolonged QT
> 1/2 RR interval
not reliable with tachycardia (>100bpm)
Aflutter with pause
can see aflutter which spontaneously breaks -> sinus pause and suddenly a junctiona escape beat followed by sinus node recover (ie sinus bradycardia etc) - sinus node dysfunction has prolonged sinus node recovery time
Digitalis toxicity
Regularized afib
aflutter with 3rd deg AVB and junctional tachycardia
prominent U-waves
Junctional rhythm
40-60bpm
Jnc Tach
> 60bpm
more likely to occur with inferior MI
Normally conducted beat after paced beat
can have twave inversion and not sensitive for ischemia so do not code ischemia changes
Failure to sense
look for premature v-pace beat (
T wave memory
T wave changes looking like ischemia persist for several days after patietn returns to normal AV conduction and v activation after prolonged 100% pacing time (or after WPW with pathway ablation now conducting through normal AV conduction system
RVH with pulm HTN/PE
Tall R wave V1
Acute PE
S wave in I (RAD from LPFB)
Q wave III
inverted T in III
Accessory pathway localization
Step 1: QRS Transition
-R/S transition before V1 (Tall R wave V1)/RBBB pattern = left sided pathway
-later than V2 (>V2) S wave in V1, LBBB = right sided pathway
-Transition V1-V2=septal
Step 2: Delta wave polarity
-positive in 2/3 leads = anterior
-negative in 2/3 lead= posterior/inferior
Brugada pattern
h/o syncope
Type I pattern (dx of brugada): J-point elevation >2mm with COVED donwloping ST segments
Type 2: J-point nelevation >2mm and saddleback shaped ST segment elevation >1mm
SCN5A
a/w threating VT arrythmias and SCD
Resemble RBBB but lacks QRS morphology c/w RBBB in other leads ie wide slurred S waves in I and V6
Electrical alternans in patient with cancer
code electrical alternans
pericardial effusion,
SR
LPFB
RAD
small r wave in I, aVL
small q in lead III
RBBB
QRS>120ms
rsR’ complex V1
wide slurred S waves I, V6
RBBB
QRS>120ms
rsR’ complex V1
wide slurred S waves I, V6
T wave inversion opposite to terminal deflection of QRS in V1, V2 - not case with V3-6 - suggests ischemia
does not interfere with ECG dx LVH or Q wave MI
LBBB
QRS >120ms
V1 - rS (tiny R, big S - wide) with ST elev and discordant twave ie upright while S is down)
or deep QS (no r)
R waves in lateral leads (I, V5,6) M shaped, notched, monophasic or RS)
Dextrocardia vs limb lead reversal
Limb lead reversal - normal R-wave progression
Dextrocardia - REVERSE R wave pgoression (starts out big)
DO NOT CODE AXIS
Dextrocardia vs limb lead reversal
Limb lead reversal - normal R-wave progression
DO NOT CODE AXIS - technical error with lead placement
Dextrocardia - REVERSE R wave pgoression (starts out big gets smaller)
DO CODE RAD…neg qrs I, postiive in aVF
R&L Arm lead reversal
transposition of leads II, III
Transposition of leads avR and avL
Precordial lead reversal
Unexplained decrease in R wave voltage in 2 consecutuive leads (ie V1, V2) with return to normal progression in following leads (V3-6)
Mobitz I - wenkebach
PR interval immediatly before non-conducted P-wave is longer than PR interval immediately following non-conducted P-wave
at level of AV node - narrow QRS
Group beating -> RR interval constant, PR interval prolongs till drops a QRS then resets…
Mobitz II
PR intervals constant with random drops of conduction
below level of node - wide QRS
LOOK FOR GROUPED BEATING…
Posterior wall MI
horizontal or downsloping ST segemnt depression with upright T waves in V1-3 with or without prominent R wave in these same leads (with or without equivalent of Q waves for posterior wall)
Digoxin toxicity
DO NOT CODE without
sagging ST depression with upward concavity -> digitalis effect
Junctional rhythm/tach
regular R-R interval no p-waves, NARROW complex
more likely with inferior MI
Prolonged QTc
> 470ms male
480ms female
Normal QT <1/2 preceeding R-R for HR 60-100 -
When measuring use lead with longest QT
WPW
if v-rate >200, QRS >120ms
Posterior MI
can’t be coded with RBBB
LAD
can’t be coded with Q wave MI (inferior?)
SVT
r’ at end of QRS complex = retrograde atrial depolarization -> best seen in V1
Acute cor pulmonale
needs sinus tach/afib - ie change in rhythm AND
right ventricular strain ie T wave inversions V1-3, ST dep
RAE
Upright 2 wave >2mm in leads II, III and aVF or >1.5mm V1,V2, RAD
LAE
notched p-wave duration >120ms
Terminal portion of p-wave in V1 >1mm deep >0.04s (1 box) duration
LAD
positive in I, neg in aVF
RAD
negative I, positive in aVF
RVH
RAD Dom R wave V1 >7mm R V1 +S V5/6 >10.5 rSR' V1 R'>10mm Secondary downsloping ST dep and T wave inversion in RIGHT precordial leads right atrial abnormality (RAE) R/S ratio in V1 or V3r >1 or R/S in v5/6 <1
Lateral MI
I, aVL
Anterior/anteroseptal
V1, V2 AND V3
ST changes of ischemia/injury
DO NOT CODE if other Q wave MI coded
LAFB
LAD qR I, avL rS in II, III, aVF QRS 80-110 ms aVL R wave >45ms avL R wave can be >11mm but no LV strain pattern so no LVH
VPC
look for compensatory pause after
QRS initial direction DIFF from QRS during SR
Sinus arrhythmia
PP intervals vary by >0.16 sec (4 small boxes)
LVH
S V1 + R V5 >35 R wave aVL+ S wave V3 >28 M >20 F S wave V1 or V2 > 30 R wave in V5 or V6>30 Max R wave + Swave in precordial leads >45
Prominent U wave
check II, V5 >1.5mm HYPOKALEMIA LVH CAD Drugs
WPW with afib
do not coce LVH, Q wave MI, ST-T chages, axis shift or IVCD
irregularity with delta wave
Afib
atrial activity seen in right precordial/inferior leads
WPW
think WPW if v rate >200/min and QRS > 120ms
initial slurring QRS
QRS>120ms
DO NOT CODE LVH/RVH
myocardial ischemia/infrction (if need to code non-specific ST changes)
PR<120
QRS >120
secondary ST chagnes opp direction of QRS
THINK WPW if afib/flutter is a/w QRS that is variabl ein width and rate >200
Dextrocardia
neg P-QRS-T in I, avL, positive P-QRS-T in avR
BUT
Reverse precordial R wave progression -> gets smaller
CODE RAD
Torsades
Find prolonged QT
Find QRS superimposed on T started NSVT (R on T)
V-rate 150-300 (200-280)
sinisoidal cycle of changing amplitude and polarity (twisting)
QRS morphology varies beat to beat
Ashman’s Phenomenon
Single wide QRS beat with RBBB morphology occuring in afib after short RR preceeded by long RR -> beat encountered a bundle that wasn't repolarized (refractory) so Wide QRS Afib Aberrant conduction (Ashman's) Aberrant conduction usually RBBB since RBB has longer refractory period than LBB
Hyperkalemia
narrow based tall peaked T wave QT shortening >6.5 1st deg AVB flat wide P wave, pwave dissappearance ST dep >7.5 - no p waves, LBBB/RBBB IVCD -> sinisoid (sinoventricular conduction) VT/VF/IV rhythm, asystole
Anterior or anteroseptal
V1-3
Anterolat
V4-6
Lateral
high lateral - I, aVL
ST/T changes c/w myocardial ischemia
ST dep WITHOUT Q waves
Anterior or anteroseptal
V1-3
Q in V1 makes it anteroseptal
Q wave MI acute or recent
Q waves and ST elev or depression
Lateral
high lateral - I, aVL
Q wave in JUST aVL does NOT qualify as lateral MI
When coding acute Q wave MI or ST-t of Injury
DO NOT CODE ST/T wave of ischemia (don’t code for ST depressions if concurrent ST elev alone or ST elev and Q waves
When coding acute Q wave MI or ST-t of Injury
DO NOT CODE ST/T wave of ischemia (don’t code for ST depressions if concurrent ST elev alone or ST elev and Q waves
Acute cor pulmonale
NEED RV strain to code this!
RAD - down in I, up in aVF
RAE - P wave in III >2.5mm
RVH - tall dominant R wave in V1 (R>S, R wave >7mm), R wave in V1 + S wave in V5 or 6 >10.5
rSR’ in V1 with R’>10mm
Secondary downloping ST depression and twave inversion in right precordia leads
RAE
ST/T changes of RVH -
RV Strain ST seg depression V1-3,
borderline LAE
S1Q3T3 (deep prom Swave in I, W wave in III, Twave inversion or lfat in III
Acute cor pulmonale
NEED RV strain to code this!
RAD - down in I, up in aVF
RAE - P wave in III >2.5mm
RVH - tall dominant R wave in V1 (R>S, R wave >7mm), R wave in V1 + S wave in V5 or 6 >10.5
rSR’ in V1 with R’>10mm
Secondary downloping ST depression and twave inversion in right precordia leads
RAE
ST/T changes of RVH -
RV Strain ST seg depression V1-3,
borderline LAE
S1Q3T3 (deep prom Swave in I, W wave in III, Twave inversion or lfat in III
Sinus tach, afib, aflutter, atach and first deg AVB
PE vs IWMI
PE doesn’t have Q wave in II (just in III)