Q is a negative (downward) deflection.
R is the positive (upward) deflection and the highest point seen on the
S is a negative (downward) deflection seen on the oscilloscope.
(5) T is the positive deflection seen on the oscilloscope occurring after QRS
complex. T represents the repolarization of the heart.
c. Switch on the synchronizer.
d. Yell, "Clear." before beginning.
e. Administer the initial shock of 200 joules. Some abnormal rhythms may be
converted with shocks as low as 10 joules.
f. Press and hold the discharge buttons on the paddles until the defibrillator
delivers the countershock.
g. If the initial countershock is not successful, use higher levels of energy on the
h. If ventricular fibrillation occurs, follow this procedure:
Turn off the synchronizer.
Charge to between 200 to 300 joules.
Figure 3-8. Electrocardiogram.