Dozens of tests can measure the health of your heart and your entire cardiovascular system. Some reveal the health of your arteries. Others monitor your hearts electrical activity. And additional tests can gauge the functioning of your heart valves and how strongly your heart beats during exertion.But some tests use radiation. Some of these screenings are quite expensive, and are covered by insurance only in certain circumstances. And, perhaps most importantly, many cardiac tests are useful only for specific patients. An expensive and powerful cardiac test may not reveal anything useful for you and your physician.