ECG from My first ECG handbook Flashcards
LQTS risk score to diagnose congenital long qts
> = 3.5
QTc to diagnose congenital long qts
> = 500 ms in the absence of secondary cause for long qt
or
480-499 + unexplained syncope in the absence of secondary cause for long qt and absence of pathogenic mutation
Qtc to diagnose short Qt
<= 330 ms
or if QTc < 360 ms with > 1 of the ff
> pathogenic mutation
> FMhx of SQTS
> FMHx of SCD age < 40
> Survival from a VT/VF episode in the absence of HF
PVC found inserted between 2 sinus beats without alteration of sinus rate, that is not followed by a compensatory pause
interpolated PVC
Onset of QRs to its peak that favors VT
> = 50 msec
RP interval that favors SVT
<= 100 msec
QRS duration that favors VT
140 ms
What sign signifies RSr’ pattern in VT
Marriott’s sign
What sign corresponds to the notching of the S wave near its nadir
Josephson
What sign corresponds to distance from onset f QRS to S wave nadir > 100 ms
Brugada sign
Where do you place the RA lead in lewis leads?
Manubrium
Where do you place the LA lead in lewis leads?
5th ICS R parasternal border
Where do you place the LL lead in lewis leads?
right lower costal margin
St depression of ____ in 2 contiguous leads may signify acute mi
> = 0.05mv/ 0.5 mm
T wave inversion of ___ in 2 contiguous leads may signify acute mi
> = 0.1 mV/ 1mm with a prominent R wave or R/S >1
STEMI criteria for all leads except V2-v3
> = 0.1 mV elevation in 2 contiguous leads
STEMI criteria for v2-v3 in women
> =0.15mV or 1.5 mm
STEMI criteria for v2-v3 in men < 40 yrs old
> = 0.25 mV or 2.5 mm
STEMI criteria for v2-v3 in men > 40 yrs old
> = 0.2 mV or 2 mm
Duration of p wave (lead ii) : PR segmet ratio in Left atrial abnormality
> 1.6
Expected axis of terminal p wave in left atrial abnormality
-30 to -90
Prominent initial positivity in lead v1 or v2 of ____ may be expected in right atrial abnormality
> =1.5mm
Increased area under the initial positive portion of the p wave in lead v1 to _ is expected in Right atrial abnormality
> 0.06 mm/sec
Expected rightward shift of mean p wave axis to ____ is seen in right atrial abnormality
> 75 deg
R peak time of ____ in V5 and V6 but normal in V1-v3 is expected in CLBBB
> 60 ms
S wave of greater duration than R wave or > ____ in I and v6 is seen in CRBBB
> 40 ms
Normal r peak time in v5 and v6 but > ___ ms in v1 is seen in CRBBB
> 50
What constitutes sgarbossa criteria
ST sement elevation >=1 mm and concordant QRS - 5 points
ST sement depression >=1 mm in v1-v3 - 3 points
ST segment deviation >= 5mm and discordant with QRS
duration of q wave in v2-v3 that may signify prior MI
> =0.02sec or QS complexes
Q wave ___ sec and ___ mv deep may signify prior MI
> = -.03 and >=0.1mv
r wave ___ sec in v1 and v2 and R/S >1 with a concordant positive t wave in the absence of conduction defect may signify prior MI
> =0.4s
In the myocyte action potential, Phase 0 represents
rapid depolarization phase where Na enters the cell
In the myocyte action potential, Phase 1 represents
early rapid REpolarization phase which is a balcne between Ca entering and K leaving the cells
In the myocyte action potential, Phase 2 represents
plateau phase which occurs because of Ca entering through slow channels
In the myocyte action potential, Phase 3 represents
final rapid repolarization where K enters the cell
In the myocyte action potential, Phase 4 represents
Resting membrane potential
In the pacemaker action potential, Phase 4 represents
Spontaenous depolarization due to inward depolarizing Na current (If)
In the pacemaker action potential, Phase 0 represents
Depolarization phase caused by inward movement of long lasting (L type_ Ca channels to reach potential threshold of -40mV
at ___ mV, transient (T type) Ca channels open causing further depolarization
- 50mv
In the pacemaker action potential, Phase 3 represents
Repolarization phase caused by inward movement of K
At the end of the repolarization in the pacemaker action potensial, the membrane potential is ____ mv
-60mv
Lead v4 is placed along the
L mid clavicular line
Lead v5 is placed along the
L AAL
Lead v6 is placed along the
L mid axillary line
What is Eithovens law?
At any given instant the potential in lead II is equal to the sum of potential in lead I and III
Most useful lead to look at when considering RV infarction
V4R