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.
The test shows the size and shape of your heart and how well your heart chambers and valves work. Echo also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and heart muscle damage caused by lack of blood flow. Echo might be done before and after a stress test (see below). A stress echo can show how well blood is flowing through your heart.