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
