In Moscow in 1996, a doctor's visit changed history

It was the fall of 1996, and Boris N. Yeltsin was running for re-election as Russia’s first president in the post-Soviet era. But he faced a crisis far more threatening than any opponent: he was desperately ill.

Mr. Yeltsin had had a heart attack. He was experiencing chest pain from angina. He needed a coronary bypass operation. But his Russian doctors said he could not survive such surgery.

For independent advice, Mr. Yeltsin reached out to an American doctor as renowned in Russia as he was in the United States: Dr. Michael E. DeBakey, the pioneering Houston heart surgeon.

Dr. DeBakey agreed to go to Moscow, and after examining Mr. Yeltsin he determined that the Russian leader could indeed survive a bypass operation. It was not widely noted in the obituaries for Mr. Yeltsin, who died last week at 76, but that consultation very likely saved his presidency, if not his life.

In doing so, it changed the course of history. Among other things, if Mr. Yeltsin had not been re-elected, he would never have had the opportunity to reach deep into the Russian bureaucracy to select Vladimir V. Putin, then an obscure functionary, as his successor.