8 steps in ECG reading

Interpreting an EKG rhythm strip: An 8 step method You You can master the interpretion of an ECG rhythm strip through practice. By developing a consistent approach you will be sure to include all the pertinent data in your analysis. This 8-step method will help you  n ECG waveform waveform has three three basic elements! elements! the " wave# the the $%& comple'# and and the T wave. These elements can be further divided into a "% internal# ( wave# &T segment# and $T interval.

Step I Evaluate the P wave. The P wave represents the depolarization of the atria. (Depolarization occurs as the impulse passes through the muscle tissue.) )bserve the " wave*s si+e# shape# and location in the waveform. ,f the " wave consistently precedes the $%& comple'# the & sino-atrial node is initiating the electrical impulse.

Step II Evaluate the atrial rhythm The " wave should occur at regular intervals# with only small variations associated with respiration. (sing calipers# you can easily measure the interval between " waves# or the "-" interval. Compare the "-" intervals.

Step III Determine the atrial rate /or a 0uic1 count# add the number of " waves in two

2-second segments and multiply by 34. To be more accurate# count the small s0uares between the ape'es of two " waves. Each small s0uare e0uals 4.45 second6 3#744 s0uares e0ual 3 minute. ivide 3#744 by the number of s0uares you counted to get the atrial rate.

4 Calculate the duration of the PR interval.

Count the small s0uares between the beginning of the " wave and the beginning of the $%& comple'. 9ultiply that number by 4.45 second. The normal interval is between 4.3: and 4.:4 second# or between three and five small s0uares wide. ,f the interval is wider# there is a delay in conduction of the impulse to the ventricles.

7 Evaluate the ventricular J rhthm (se calipers to measure the %-% intervals. "lace the calipers on the same point of the $%& comple'. ,f the %-% intervals remain consistent# the ventricular rhythm is regular.

6 etermine  the ventricular rate ; (se the same formula for calculating the atrial rate &tep 2# but count the small s0uares between the two % waves. lso chec1 that the $%& comple' is! shaped appropriately for the lead you*re monitoring.

< Calculate the duration of the !R" comple# 

Count the s0uares between the beginning and the end of the $%& comple' and multiply by 4.45 second.  normal $%& comple' is less than 4.3: second. &ome references specify 4.4= to 4.34 second as the normal duration for the $%& comple'.

$ Calculate the duration of the !T interval  Count the number of s0uares from the beginning of the $%& comple' to the end of the T wave. 9ultiply this number by 4.45 second. The normal range is 4.2= to 4.55 second# or > to 33 small s0uares wide.