Over the long run, however, the policies of the one-drop rule and segregation, in conjunction with other factors such as a long tradition of racial nationalism and white liberal support, generated a counter-reaction that led to a very different form of racial politics.
Learn about these ultrasound-like tests of the heart -- and find out what to expect -- here. Cardiac Catheterization. Cardiac catheterization -- also called a coronary angiogram -- means running a catheter into your heart. It's done to help doctors see what's going on in there, and whether they need to operate. Here's where to learn about it.
Heart biopsy. If your doctor is taking a sample of heart tissue (biopsy), the catheter will usually be placed in the vein in your neck. Less often, it may be placed in your groin. A catheter with a small, jaw-like tip is used to obtain a small sample of tissue from your heart.