Good day from New York. For a second Saturday in a row a "routine" medical procedure involving one of this nation's leaders is making news. A week after president Bush's colonoscopy, vice-president Dick Cheney went briefly under the knife today to have a battery replaced in his implanted heart monitoring device. The device is designed to deliver a potentially life-saving shock to the heart if it ever went out of rhythm. The VP has suffered four heart attacks. On the broadcast tonight we'll be talking to a distinguished cardiologist, who will explain how the procedure is done, how the device works, and what risks are involved.

Our white House correspondent John Yang will tell us about a Bush administration plan to sell arms to Saudia Arabia and several other moderate Arab governments. The sale is considered a way to contain Iran, but it is not expected to sail through Congress. As John will explain, there is some uneasiness on Capitol Hill over Saudi Arabia's role in the war in Iraq.

We have more video and eye witness accounts of that disasterous collision in the skies over Phoenix Friday involving two TV news helicopters. NBC's Pat Dawson will look at the crash and the story that put those two choppers over the same piece of real estate -- a high-speed car chase. Could this accident become another reason many police departments are re-evaluating their policies regarding when, and when not to chase a fleeing car?

Also tonight, Lee Cowan reports on today's tearful memorial for the Connecticut mother and her two daughters who were brutally murderded in a home invasion this week.

Plus, Andrea Mitchell reports on how a newspaper item that mentioned senator Hillary Clinton's cleavage, has become a part of her efforts to appeal to women voters.

We'll look for you tonight on NBC Nightly News.