Cooperative study on cardiac catheterization. Alterations in cardiac catheterization techniques during the course of the study.
D000790:Angiocardiography; D006328:Cardiac Catheterization; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging; D006801:Humans; D008722:Methods; D011182:Postoperative Care; D011183:Postoperative Complications; D011300:Preoperative Care