ECG interpretation - Download as DOC by 99x64kq9


									ECG evaluation-
Record your measurements on the write up page (last page) where you will mount your
ECG strip for viewing

Remember to run through this checklist as you first scan any ECG:

      Orient the paper strip right side up

      Identify the paper speed, sensitivity, and confirm that you are reading lead II

      Identify the R waves, then the P to the left, and the T to the right

      Check rate using the R waves and paper mark--Is the heart rate too fast or too

      Check the R—R interval --Is the rhythm regular or irregular?

      Check the P waves—Are the P waves visible and do they all look alike?

      Check the QRS--- Do the QRS waves all look alike? Are any of the QRS waves
       wide or bizarre looking?

      Check the relationship between the P and QRS—Is there a P wave for every
       QRS? Is the P-R interval normal and consistent?

As you prepare to write up the measurements, take these steps:

   1. Determine rate- there are several methods but try this one

       10 or 20 method- usually there are regular hash marks at the top or bottom of the
       strip (not the lead markers)
               Count the number of complexes that occur in 3 seconds
               At 50 mm/sec paper speed, the hash marks are 1.5 sec apart
               At 25 mm/sec paper speed, the marks are 3 sec apart

              Multiply the number of complexes in 3 seconds by 20= heart rate
       Or     Multiply the number of complexes in 6 seconds by 10= heart rate

   2. Determine if rhythm is regular or irregular: check the R-R intervals

       Paper and pencil method- take a piece of paper and line up the edge across two R
       waves. Mark a notch on the paper at the top of each R wave peak. So you will
       have 2 marks on the edge of your paper that shows you how far apart those R
       waves are. Use this to compare the spacing between the other R waves. The marks
       should line up fairly closely to the other R waves. If not, the rhythm is irregular.

Now find a representative PQRST to make your specific measurements:
   3. Evaluate P waves- this gives us information about the atria

       Are the P waves visible and do they all look alike?
       Are the P-P intervals regular – use the paper and pencil method to check
       Record the height and width of a representative P wave
       if the P waves are not uniform, note a range of measurements for height and width

   4. Evaluate QRS waves- this gives us information about the ventricles

       Do they all look alike?
       Record the height and width of a representative QRS wave
       If the duration (width) is greater than 0.06 sec than there is abnormal conduction
       in the ventricles

   5. Evaluate P-QRS relationship using the PR interval- this tells us if the atria and
      ventricles are working together or if there is a heart block

       Is there a P wave for every QRS?
       Is there a QRS for every P wave?
       Are the P-R intervals all the same?
       Record the P-R interval

   6. Evaluate T wave- this gives information about the repolarization or relaxation
      phase of the ventricles
      Sometimes electrolyte problems, calcium imbalances, drug reactions, or
      ventricular muscle hypoxia will change the T wave and associated measurements

       Record the height of the T wave- it should be no greater than 25% of the R wave
       Observe the S-T segment- if it is 0.2 mv above or below the baseline, record it
                                      if below- it is “depressed”, if above- it is “elevated”
       Record the Q-T interval width- longer than normal is important information,
       especially if the animal is on medication

   7. The big picture- look over an entire strip and view for unusual elements, weird
      waveforms, patterns, or artifacts.
      Artifacts- respiratory, electrical interference, muscle tremors, purring

8. Now you have enough information to know if your patient has a normal rhythm or not!
If you answered no to any of the above questions- there may be an arrhythmia. Plus, any
abnormal measurements give information as to the type of arrhythmia present, possible
causes, and if there is heart enlargement. Neato!!
ECG Lead II in the dog                     Name____________________________

Paper speed is at ______________ sensitivity is at ___________________

Tape ECG strip here

   1. Heart rate __________________ Is the heart rate normal or abnormal?______________

   2. R-R intervals are regular or irregular?____________________

   3. P waves: height____________(max 0.4 mv) width ___________(max 0.04 sec)

       P waves are WNL and uniform? _____________________

   4. QRS waves: height___________(max 3 mv) width__________(max 0.06 sec)

       QRS waves are WNL and uniform?_________________________

   5. P-R interval: width______________(0.06-0.13 sec)
                                        (or at 50 mm/sec paper speed: 3-6 1/2 boxes)

       Is there a P wave for every QRS? __________

       Is there a QRS for every P wave?___________

       Are the P-R intervals WNL and uniform?_____________

   6. T wave height ____________________

       Is the T wave height 25% or less than the height of the R wave?___________

       Is the S-T segment isoelectric, depressed, or elevated?_____________________

       Q-T interval: width _______________(0.15- 0.25 sec)

       Q-T interval is WNL? __________________

   7. Any artifacts or unusual waveforms? ___________________________________

   8. You now know that this ECG tracing is basically: a. Normal or b. Not perfectly normal

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