e. QRS Complexes. These complexes represent ventricular depolarization.
The QRS complexes should be of equal duration.
Here is an analysis of the parts of the QRS complex.
(a) Q waves are a negative deflection on the oscilloscope. They follow
the P waves.
(b) R waves are a positive deflection on the oscilloscope, and they
follow the Q waves.
S waves are a negative deflection on the oscilloscope following the
Figure 2-10. Electrocardiograph waves, segments, and intervals.
(2) Check the measurement of the QRS complex. The complex should be
less than 0.12 seconds. See if the measurement is within normal limits. See if all the
QRS complexes look alike. If there are any unusual QRS complexes, determine if they
are associated with ectopic beats (abnormal heartbeats).