Click to download
ELECTROCARDIOGRAM REVIEW
by Nincy Samuel, Western PA student

When reading an EKG, it is vital to have a systematic approach!
- Determine Cardiac Rhythm
- Is the rhythm regular or irregular?
- Identify atrial activity
- Determine P-QRS relationship
- Measure heart rate
- Is the rate normal? (60-100 bpm) bradycardia (<60bpm)? Or tachycardia (>100 bpm)?
How to determine heart rate: count the number of small squares (0.04 secs) between two QRS complexes

5 small boxes between the 2 QRS complexes |
300 bpm |
10 small boxes |
150 bpm |
15 small boxes |
100 bpm |
20 small boxes |
75 bpm |
25 small boxes |
60 bpm |
30 small boxes |
50 bpm |
35 small boxes |
43 bpm |
40 small boxes |
37 bpm |
- Evaluate P wave morphology
- Inspect P waves in lead II and VI for right and left atrial enlargement
- What is the amplitude? Duration? Direction?

- Assess PR, QRS, and QT interval
- PR interval- normal is 0.12-0.20 seconds. Is it short or prolonged?
- Short PR intervals (less than 0.12 second) indicate that the impulse originated somewhere other than the SA node. This variation is associated with junctional arrhythmias and preexcitation syndromes.
- Prolonged PR intervals (greater than 0.20 second) may represent a conduction delay through the atria or AV junction due to digitalis toxicity or heart block – slowing related to ischemia or conduction tissue disease.
- QRS interval- normal is (less than or equal to 0.10 seconds.
- Make sure to check for a bundle branch block!

- QT interval- what is the duration? Normal QT is less than or equal to one-half of the R-R interval (if HR is normal
- )

- Determine Mean QRS Axis
- Normal is between +90 degrees and -30 degrees
- Is there left or right axis deviation?
- Check leads I and aVF!



- Evaluate QRS Complex, ST and T wave Morphologies
- Is a Q wave present? If it is, what is the distribution?
- Q waves are normal at a width of <0.04 seconds and height of <1/3 of the QRS complex


- Is the QRS amplitude normal? Increased? Or decreased?
- Check for left or right ventricular hypertrophy!



- Is the ST segment elevated, depressed, or isoelectric?
- Check for ischemia, infarction, pericarditis, metabolic/chemical abnormalities!

- Is the T wave upright or inverted?

- Is the amplitude increased or diminished?
- Identify Abnormal ECG Pattern
- Myocardial ischemia and infarction
- Cardiac chamber enlargement and hypertrophy
- Arrhythmias and conduction disturbances
- Miscellaneous patterns (e.g., pericarditis, WPW syndrome, electrolyte imbalances, drug effects)

References:
Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine
Clinical Cardiology Made Ridiculously Simple (Edition 4)
Rutgers PANCE/PANRE Review Course
http://www.medskills.eu/index.php/wiki/en/cellular/chest%20pain/heart%20and%20blood%20vessels/ecg%20presentation/
http://www.teaems.com/ekg-review.htm
Fitsweb.uchu.edu
l
Leave a Reply