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
Lead v7 is placed along the
left posterior axillary line
Lead v8 is placed along the
mid scapular line
Lead v9 is placed along the
left paravertebral line
normal duration of p wave
0.12 s
normal amplitude of p wave
< 0.25 mV
By convention deflections on the ECG that are greater than ___ mV are referred to in capital letters
0.5 mV or > 5 mm
QT represents
total ventricular activation and repolarization
Qt varies as much as ___ s
0.05 to 0.065s
QT interval is best determined in the lead with ____
longest QT interval (usually V2, V3) without a u wave
Usual amplitude of u wave
< 0.1 mV in height
U waves are sually largest in leads ___
v1 and v2
Axis deviation of tricuspid atresia
LAD
Axis deviation of ostium primum ASD
LAD
Axis deviation of pectum excavatum
RAD
Axis deviation of VSD
RAD
Axis deviation of ASD
RAD
Axis deviation of ventricular arrhythmia
Extreme
Amplitude of R in V1 to qualify for RVH
> = 7 mm or >5 mm if R/S >1
Amplitude of S in V5 or V6 to qualify for RVH
> = 7 mm
Amplitude of S in V1 to qualify for RVH
< 2 mm
Amplitude of R in V5, V6 to qualify for RVH
< 3mm
Duration of the notch of p wave to qualify for LAA
> 40ms
Most common IVCD
LAFB
Most common cause of marked LAD
LAFB
Percent of people with LBBB with no heart disease
10%
Type of MI related to PCI
4a
Troponin must be >5x the 99th percentile of URL
Type of MI related to stent thrombosis
4b
Type of MI related to CABG
5
Troponin must be >10x the 99th percentile of URL
Pathologic q waves occur within ___ hrs of MI
6-16h
When do you consider RV infarction (STE in what leads)
STE in V1 or STE in III>II
Most common correctable cause of AF
Hyperthyroidism
2 ddx for long RP
Atrial tachycardia, Atypical AVNRT
Most likely diagnosis for short RP < 90 ms
AVNRT
Most common type of arrhythmia
Sinus arrhythmia
Most common form of pSVT
AVNRT
Another term for Typical AVNRT
Slow -fast type
More common (>80% of AVNRT)
Percentage of wide complex tachycardia caused by VT
80%
Mechanism of AIVR in digitalis intoxication
Triggered activity
Most likely mechanism of VT in the absence of structural heart disease
Abnormal automaticity or triggered activity
Most likely mechanism of VT WITH structural heart disease
Re entry
ECG stages of pericarditis
Stage I - diffuse concave upward STE with PR depression
Stage II - resolution PR depression
Stage III- T wave inversion
Stage IV- normal
ST/T of acute pericarditis
> 25%
ECG changes of hypothermia occur at body temperatures at ___
< 34C
Osborne waves are most prominent in which leads
v2-v5
most common ECG changes in cerebrovascular accident
diffuse deep inverted t waves
First ECG change in hyperkalemia
tall, peaked, symmetrical T wave
K level that causes widening of QRS
K> 6.5 mmol/l
K level that may cause dec p wave amplitude and prolonged PR, possible AV blocks
K > 7 mmol/l
most common ECG finding in PE
sinus tachycardia
Lead reversal that causes inversion of lead I and positive p and t in avr
LA/RA
Lead reversal that causes inversion of p and t waves in inferior leads with negative QRS in III and avf
RA/LF
Lead reversal that causes flat line in lead III
LA/RF
most common mode of dual chamber pacemaker
DDD
Name of mode with asynchronous firing
VOO
Class I Indications for ICD insertion in ventricular arrhythmia
Survivor of cardiac arrest by VF/VT without reversible cause
Structural heart disease with spontaneous sustained VT
Unexplained syncope with hemodynamically significant VT or VF during EPS
Class I Indications for ICD insertion in heart failure
LVEF <= 35% in NYHA II and III and has not had an MI within 40 days
LVEF <= 30% in NYHA I > 40 days post MI
Non sustained VT due to prior MI with LVEF <=40% and inducible VF or sustained VT in EPS
other term for biventricular pacing
Cardiac Resynchronization Therapy
Class I indications for CRT
If NYHA II,III and IV +
LVEF <= 35%, QRS >=150 ms, LBBB, NSR
Most SCDs are attributable to ____
CAD
In CAD, what is the major determinant of inc risk of SCD
LV dysfuncion
In CAD, short term risk of SCD is associated with
acute ischemic phase of MI
In CAD, long term risk of SCD is associated with
myocardial scarring, remodeling, cardiomyopathy and HF
Mechanism of SCD in HF or dilated CM
tachyarrhythmia (VT/VF) or non shockable bradyarrhythmia or asystole
Major gene mutation associated with ARVC
Plakophillin 2
Mutation assoc with Brugada syndrome
SCN5A
Mutation assoc with Catecholaminergic polymmorhic ventricular tachycardia
heterozygos missense mutations in RyR2 as well as mutations in calsequestrin gene
Associated arrhythmia with WPW
AVRT and AF with preexcitation
Abnormal q wavesin inferior and lateral walls reflect _____
septal depolarization of the hypertrophied myopathic tissue
Apical variant of HCM may have these ECG findings
LAD, deeply inverted t waves
DOC for HCM
beta blocker and non DHP CCB
