U.S. Vice President Dick Cheney was admitted to a hospital yesterday for undergoing an advanced test of his heart and the implant that regulates his heartbeat. A spokesman for Cheney said the Vice President was taken to the George Washington University Medical Center in Washington on Friday Morning, where he is undergoing a physical exam, electrocardiogram, an echocardiogram and a stress test. While the spokesman said the tests were routine, interest is always high in the heart-health of the Vice President, who has had four heart attacks. Cheney's last check-up, in May 2004, revealed his health was fine.