5- Intro To 12 Leads Flashcards
2 types of leads
Hexaxial (Limb)
Precordial (Chest)
Locations for the precordial leads
V1- 4th ICS R of sternum V2- 4th ICS L of sternum V3- Between V2 and V4 V4- 5th ICS mid clavicular V5- Between V4 and V6 V6- 5th ICS mid-axillary
Name the charges of RA, LA, LL and the polarity of them all
RA -
LA -,+
LL +
Bipolar polarity
Name the charges of AVR, AVL, AVF and the polarity of them all
AVR +
AVL +
AVF -
Unipolar polarity, augmented voltage
Augmented vectors R, L, F
What is the polarity of the precordial leads
Unipolar
What does each lead look at
1 - Lateral
2 - Inferior
3 - Inferior
AVR - None
AVL - Lateral
AVF - Inferior
V1 - Septal V2 - Septal V3 - Anterior V4 - Anterior V5 - Lateral V6- Lateral
6 step process of reading a 12 lead
- Calibration
- Determine the rhythm
- QRS assessment
- Hypertrophy
- Axis deviation
- Ischemia/Infarction
What to look for with calibration
The box is 10 tall and 5 wide
What to look for with the QRS
R wave progression
What is proper progression of the R wave from V1-V6
V1- Down V2- Down V3- Biphasic V4- Biphasic V5- Up V6- Up
6 causes of poor R wave progression
LBBB (very late) LAFB Certain WPW’s (early) RVH LVH Anterior MI (old MI)
How to determine axis deviation and the 4 kinds
I and AVF
Normal I up AVF up
Left I up AVF down
Right I down AVF up
Extreme right I down AVF down
7 causes of L Axis Deviation
- Normal in obese, old, or pregnant patients
- Emphysema
- LVH
- LAFB
- Inferior MI
- LBBB
- VTach
5 causes of R Axis Deviation
- Emphysema
- RVH
- LPFB
- RBBB
- VTah
2 causes of Extreme R Axis Deviation
- Bifasicular heart block
- VTach
How to confirm a bundle branch block (2)
- Wide QRS or “rabbit ears”
- V1 up or down from jpoint
The cause of LBBB
MI, new onset LBBB = MI
Causes of RBBB (5)
- Anteroseptal MI
- Pulmonary embolism
- CHF
- HTN
- Myocarditis/Pericarditis
Characteristics of a Left Anterior Fascicular block (3)
- LAD
- Q wave in I, R wave in III
- Common to have RBBB
Characteristics of a Left Posterior Fascicular block (2)
- RAD
- R wave in I, Q wave in III
Signs of RAE (2) and 3 causes
- Teepee shaped PWave
- V1 biphasic wave
Causes
-COPD, PE, Pulmonic HTN
Signs of LAE and 2 causes
-Wide or notched/double humped PWave
Causes
- HTN
- LVHF
Signs of RVH
- Rs pattern
- RAE
- RAD
-Not RVH if:
RBBB, Posterior MI
Signs of LVH
V1 or V2 - deflection
Plus
V5 or V6 + deflection
