ECG INTERPRETATION HALLMARK OF THE TRAINING PART 2

3.T wave 

The T wave indicates the repolarisation of the ventricles. 

Follows the QRS complex. Take note of T waves which have a 1.downward (negative) deflection ischemic changes indicates  or 2. tall, pointed peaksT waves- indicates hyperkalemia

 
Sometimes we see a U wave.
4.The U-wave is a small upright, rounded bump. When observed, it follows the T-wave.indicates Late repolarisation of the ventricles.

 

 
    STEP 4.INTERVALS

I -PR INTERVAL

The PR Interval indicates AV conduction time.   

The interval is  from where the P wave begins till  the beginning of the QRS complex.  

Count the small boxes  to determine PR Intervals. 

Normal PR  interval is 0.12 to 0.20 seconds (3 to 5 small boxes) 

This interval shortens with increased heart rate.
 

Evaluate if PR Intervals are constant or varying across the EKG strip. 

If they vary, determine if the variations are a steady lengthening until the point where an expected QRS does not appear.

PR Interval questions to address:

• Does the PR-Interval fall within the norm of 0.12-0.20 seconds/120-200 ms?


• Is the PR-Interval constant across the ECG tracing?

II-QT INTERVAL

The QT interval represents the time of ventricular activity including both depolarization and repolarisation. Measured from the beginning of the QRS complex to the end of the T wave. 

Normal, the QT interval is 0.36 to 0.44 seconds (9-11 boxes). The QT interval will vary with patient gender, age and heart rate. 

Criteria-Another guideline is that normal QT Intervals is less than half of the R-R Interval for heart rates below 100 bpm.

Abnormalities associated.-LONG QT SYNDROME.