1-13
1-13. INTRAVENOUS ANGIOCARDIOGRAPHY
This is a procedure in which an opaque medium is injected into a vein followed by a rapid series of x-ray pictures taken of the course of the medium through the heart, to the lungs, back to the heart, and out through the aorta. The dosage of contrast media is calculated according to the kilograms of body weight. The solution is injected through a large bore (12 gauge) needle held in position in the vein, usually by a "cut down." Speed of injection is imperative, since the solution must pass through the heart in a large bolus to make possible a good examination. The solution is injected after the patient has been instructed to inhale deeply. The inspiration is held for the entire series of x-rays.
a. This diagnostic method is recognized for precision in detecting congenital cardiac defects. Individual chambers of the heart are visualized, pathways for the blood stream are demonstrated, and chamber enlargement can be seen.
b. The opaque medium may cause a flushing sensation as it flows through the body. If necessary, the studies may be conducted under mild anesthesia. After one complete circulation, the opaque media is so diluted that it is no longer visible by x-ray.
c. No special preparation of the patient is necessary unless anesthesia is to be given. In that event, food may be withheld prior to the studies. A record of the patient's weight should be sent to the x-ray department with him.
