Chapter 4- ECG Flashcards
***Hexaxial (Limb) Leads look into what plane? ______Triangle, include leads ____ , ___ and _____These leads are
look in frontal plane) – Einthoven’s triangle – Leads I, II, III Bipolar pos and neg poles
*****aVR, aVL, aVF • Unipolar What does the letter stands for?
• aV = “augmented voltage” • R = Right arm • L = Left arm • F = Foot
****Precordial Leads look into what plane? what are the leads?
look in transverse plane – v1 through v6
***Lead II
Conduction system pointing toward lead II
**** I, aVL: lateral
Lateral
**** II, III, aVF:
inferior
**** aVR:
superiomedial
What are the precordial leads
V1-V6
****Anterol septal looks at
V1, V2
*****Antero apical
V3, V4
*****Anterolateral
I, aVL, V5, V6
*****Interior
II, III, aVF
****Anteroseptal wall infarct include
V1-V4
*****Lateral wall infarct include
I, avL, V5, V6
*****Inferior wall Infarct include
II, III
QRS axis should be between _____to ______
-30 to +90, represents average direction of ventricular depolarization in frontal plane based on leads I and II
________represents abnormality
Deviation
***Right axis deviation ***Left axis deviation
> +90 degrees
***Causes of left axis deviation (ILLeftANL)
Inferior wall MI Left anterior fascicular block LVH
****Causes of Right axis deviation (RAleftPo)
RVH Acute R heart strain Left posterior fascicular block
****How to determine MEAN QRS AXIS ? The more perpendicular the axis is to a lead,
****the more isoelectric the QRS complex will be
P wave abnormalities (ATRIAL ENLARGEMENT)
Best seen in Lead II & V1
P wave abnormalities *****Lead II views which axis ? what plane ATRIAL ENLARGEMENT in _____leads what plane?
RA depol. almost immediately followed by LA depol. Both superimposed. Perpendicular axis FRONTAL V1 Transverse
STEP to find Axis deviation
- FIND ISOMETRIC LEAD 2. FIND LEADS PERPENDICULAR TO ISOMETRIC LEAD
***Best to look for atrial abnormalities
Lead II and V1
***Ventricular abnormalities best seen in ___and ____
V1 and V6
**** Right Ventricular Hypertrophy
RIGHT AXIS DEVIATION Wide R in V1 Deep S in V6
*****LEFT Ventricular hypertrophy
LEFT AXIS DEVIATION Right axis deviation Deep S in V1 Tall R in V6
***BBB best seen in ____and ______ .
V1 and V6
****RBBB in ______ you will see ____ “______”
V1; RSR’; RABBIT EARS V6 prominent S with late R depolarization
***LBBB in ______ you will see ______
V1; prominent S V6 notched R (similar to rabbit ear)
***ST elevation is
First sign of MI STEMI (ST elevation myocardial infarction
****Pathologic Q waves Develop where? They are _____ Occur in ______ Do NOT INDICATE _____
In leads overlying infarcted tissue Permanent evidence of MI Groups of leads When injury occurred, could be acute or years ago
***Explain pathological Q waves
Dead infarcted tissue under lead has no electrical activity and act as a window for lead to see opposite side of the heart depolarizing away from lead causing downward deflecting pathological Q wave
LA or RA enlargement

RA enlargement

LA vs RA enlargement

LA enlargement
