Lecture 17: Normal ECG Part I and II Flashcards
Label these on an EKG PR segment PR interval ST segment QRS interval QT interval Equivalent time and voltage between large and small boxes
Ok
What are the characteristics of a normal P wave?
Upright in 1,2, V4-6, aVF
Inverted in aVR
Variable in the rest
What are the characteristics of a normal P-R interval?
Length should be 0.12 - 0.2 s
What are the characteristics of a normal QRS?
Length 0.5 - 0.10 s
What are the characteristics of normal Q waves?
<0.03s
What characterizes a narrow Q wave? What leads are these read as normal?
1-2 mm
1, aVL, aVF, V5-6
What are the characteristics of a normal ST segment?
Compare to PR segment baseline, shape
How much can ST segment be elevated in standard leads?
How about precordial leads?
<1 mm
<2mm
An ST depression >1/2 mm means?
An ST prominent ST elevation means?
- subendocardial injury/ischemia
- epicardial injury/ischemia
What are the characteristics of a normal T wave?
Upright in 1-2, V3-6
Inverted in aVR
Variable in other leads
How much can a T wave be elevated in standard leads?
How about precordial leads?
<5mm
<10mm
What can QT abnormalities mean?
What can T wave abnormalities mean?
What does ST elevation mean?
What does Q/QRS abnormalities mean?
- MI, injury or ischemia
- STEMI, MI, hyperkalemia
- MI
- necrosis
What Is the axis reading? 1 = +, aVF = + 1 = +, aVF = - 1 = -, aVF = +1 1 = 1 -, aVF = -
Normal axis (0/-30 to +90)
LAD
RAD
Extreme axis deviation
What are 2 ways to calculate rate?
- Use QRS alignment and count
- Divide 300 by number of large boxes
What is always important to keep in mind when seeing EKG abnormalities?
.
Correlate with history, more alarming if there are symptoms like CP etc.. Some healthy people just have abnormal waves
What does a wide P wave mean?
What does a prominent P wave mean?
P mitrale - left atrial enlargement
P pulmonale - pulmonary disease
What does prominently depressed ST segment mean?
What does flat ST segment mean?
What does prominently elevated ST segment mean?
- CAD
- ischemia
- MI (but can also be normal depending on person, correlate with hx)
What needs to be present for normal sinus rhythm reading?
What leads are best for reading these?
P waves before QRS
2 and V1
If P-R is normal length, what does that mean?
If QRS is normal length, what does that mean?
- No AV block
- No bundle branch block
If P waves appear after QRS, what does that mean?
If P there are no P waves, what does that mean?
- SVT, junctional rhythm
- Afib, flutter, vtach
Draw the 12 axis schematic including the areas of positive and negative deflection
Ok
How do you determine the precise axis?
Look at 1 and aVF.
Measure boxes from baseline above and below and add them.
Graph the deflections (+ is toward the lead, - is away from the lead).
Where they meet is the precise axis.
