Day 2 Flashcards
Review the etiologies of bundle block.
- Iatrogenic (ablation, cardiac surgery)
- Endocarditis
- Ischemia
- Age-related degeneration/sclerosis
- Sarcoidosis
- Chagas disease
Define maven.
(n.) A person who is an expert in some field
Example: “She is a grammar maven.”
________ causes left-axis deviation.
Left anterior fascicle block
You see Q waves in aVL, II, and III. There is left-axis deviation. What is the cause?
IMI with LAFB (“the pupu platter”)
What is the “small-f flitter sign”?
Inverted P wave in aVL, suggestive of COPD
An axis greater than 120º is one of two things: ____________.
- Left posterior fascicle block
- Right ventricular hypertrophy
RVH is much more common.
LPFB causes _______-axis deviation.
right
Why does an RBBB lead to the RSR’ formation?
The wave passes to the left ventricle first and then the right ventricle.
In RBBB, there is abnormal QRS and abnormal __________.
T waves: they are generally inverted; if they are normal, then that is worrisome
A QRS greater than ________ is diagnostic of complete RBBB (if other features are present).
120 mS
If the QRS is > 120 mS, then the diagnosis is incomplete RBBB.
With a RBBB, you need to subtract the ________ to evaluate the axis.
terminal S wave (the post-block section of the QRS)
Describe the rule of III vs. II.
- If the R wave in III is greater than in II: axis >90º
- If the R wave in III is the same as in II: ~90º
- If the R wave in III is less than in II: <90º
If the R is greater than R’ in a RBBB (that is, the first R is larger than the second R), then it is likely a ______________.
superimposed posterior infarction
Interpolated PVCs are PVCs that _____________.
don’t interrupt the rhythm
In LBBB, list the axis orientations in order of best to worst prognosis.
- Normal
- LAD
- RAD
What is the “small f Flitter” sign?
Inverted P wave in aVL indicates vertical heart with likely COPD
When you assess axis in a person with a BBB, you need to ______________.
consider only the pre-BBB section of the QRS complex
So if lead I has an upright R and then an inverted, wide S, only consider the R because the S is an artifact of the RBBB.
Rate-related BBB occurs with ___________.
tachycardia
The more common type of bifascicular block is _____________.
LAFB and RBBB
LPFB and RBBB is the less common type.
When the R is greater than the R’ in V1-V3, you must consider ______________.
RBBB with older posterior MI
List the three ways you can diagnose an old MI in someone with a LBBB.
- Cabrera sign: a Q wave with a notch on the right side
- Chapman sign: an R wave with a notch on the right side
- Q waves in I and aVL: old anteroseptal
Chapman and Cabrera just tell you that there was an MI somewhere.
What are the criteria for diagnosing an acute MI in LBBB?
Sgarbossa criteria:
• > 1 mm of ST elevation that is concordant with the QRS complex
•> 5 mm of ST elevation that is discordant with the QRS complex
•ST depression in V1-V3
