e. Studies now also include the examination of both sides of the heart
simultaneously through the transthoracic introduction of two needles, one in each
f. The patient is taken to the fluoroscopy or cardiology department for the study.
The entire procedure may last from 1 to 3 hours. The procedure is a painless one. The
patient is prepared as follows:
Solid foods are withheld. Liquids are permitted up to 3 hours prior to the
Diphenhydramine and Valium may be given 30 minutes prior to the
A systemic antibiotic may be administered prophylacticly to prevent
(4) After the procedure the patient is returned to his nursing unit, remaining
flat in bed for 24 hours or more. The vital signs and insertion site are checked every 10
minutes during the first hour, then every 30 minutes for 3 hours. The patient may be
nauseated following the procedure.
a. The electrocardiogram (ECG or EKG) is a graphic recording of the electrical
impulses produced in association with the heartbeat. Impulse formation and conduction
produce weak electrical currents that spread throughout the entire body. By connecting
certain points on the body to a recording instrument, these currents can be recorded as
a graphic representation of the heartbeat, measured against time. Time is expressed
on the special ECG graph paper by vertical and horizontal lines.
b. Normally, each heartbeat is represented as five major waves: P, Q, R, S, and
T. The Q,R, and S waves all represent the same portion of the heart and are referred to
as a unit: the QRS complex.
(1) The P wave represents atrial depolarization. The QRS complex
represents ventricular depolarization.
(2) The QRS complex represents the impulse traveling through the
ventricles, at which time there is no heart contraction.
(3) The T wave is produced by electrical recovery of the ventricles, at which
time there is no heart contraction it represents ventricular repolarization.