Passage of a long, flexible tube into the heart chamber through a vein is called cardiac:

Question

Quizplus · Accepted Answer

Cardiac catheterization involves passing a long, flexible tube (catheter) into a heart chamber through a vein, making this the correct choice. Echocardiography uses ultrasound to create images of the heart and Electrocardiography measures the electrical activity of the heart. Resuscitation involves trying to revive a person who has stopped breathing or whose heart has stopped beating.

Passage of a Long, Flexible Tube into the Heart Chamber