Boris Yeltsin's brave and troubled heart took its first rest Tuesday in nearly 66 years.
Chilled by a cocktail of tube-fed drugs, it grew weaker and beat more slowly until the spikes on the electronic heart monitor flattened to a horizontal line. The heart collapsed into the Russian president's chest, and the most crucial hour of his long-needed heart bypass surgery began.
For the next 68 minutes, while a mechanical heart-lung pump kept oxygenated blood flowing through Yeltsin's anesthetized body, Dr. Renat Akchurin took the future of this volatile country into his skilled hands.
Akchurin stitched five detours around gummed-up parts of Yeltsin's coronary arteries. The operation--aimed at restoring a normal flow of blood and oxygen to the heart muscle and thus lowering his risk of stroke or another heart attack--was later termed by Akchurin "sufficiently successful."
Here is a look at what ailed the Russian president, what was done to fix it and what dangers he still faces in recovery.
Plaque buildup caused by arteriosclerosis narrowed three branches of Yeltsin's left coronary artery--the artery that serves the main pumping chamber of the heart--and fully blocked his right coronary artery. This constriction led to myocardial ischemia, an inadequate supply of blood and oxygen to the heart muscle.
The president was hospitalized twice last year for what the Kremlin called acute episodes of ischemia. He put off needed surgery to run for reelection and suffered a mild heart attack in late June--a fact kept secret until after his July 3 victory in the runoff election.
Yeltsin was later diagnosed as having stunned myocardium: His restricted blood flow prevented parts of his heart muscle from contracting properly. But doctors said last week that his heart showed no major scars or lasting damage and was strong enough to withstand surgery.
Akchurin performed the surgery at the Moscow Cardiological Center's Finnish-built, high-tech operating theater, aided by 11 Russian doctors who have worked with him as a team for 14 years.
They opened Yeltsin's chest with a scalpel, parted his breastbone down the middle with a power saw and activated the heart-lung pump.
Each bypass vessel was fashioned out of healthy but expendable tubes taken during the operation from Yeltsin's body--a piece of a leg vein and a mammary artery. The surgeons knew they had to install at least three bypasses but were able to do five.
Leaving one end of the mammary artery attached indirectly to the heart, the doctors pulled the other end loose from Yeltsin's ribs and grafted it onto one of the narrowed branches of the left coronary artery downstream from the blockage.
The piece of vein removed from the leg was cut into four shorter tubes. One end of each tube was grafted to the aorta, the inch-wide artery that carries all blood away from the heart; the other end was grafted to a coronary artery.
These bypass vessels, no wider than soda straws, were grafted by microscopic sewing in which Akchurin's hand guided tiny curved needles with tweezers as long as chopsticks. A microscope more powerful than the jeweler-type loupes worn by most heart surgeons enabled him to use needles and sutures that were far thinner--and, he says, created seams that are more durable--than usual in heart surgery.
Then came the tensest moment--reviving Yeltsin's heart.
Taking the patient off the heart-lung machine allows blood to flow again into the heart. About one-third of such patients in Russia need additional stimulus--such as electric shock--to get the heart pumping again. Yeltsin did not.
Yeltsin regained consciousness after the operation but is not out of danger.
Bypass surgery subjects the heart and lungs to trauma. Yeltsin remained on a respirator until doctors could determine that his lungs could work again on their own.
Doctors must also monitor his heartbeat, which was somewhat weaker than normal before surgery, and his blood pressure--to make sure they recover and remain at normal levels.
Blood clotting is another potential side effect; it could cause a stroke. Irregular blood pressure can put a strain on the kidneys and liver. Yeltsin's age adds to the risk of complications.
The first 72 hours after the operation will be the greatest period of risk for the Russian leader.
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Yeltsin's Bypass Surgery
Russian President Boris N. Yeltsin, originally scheduled for three bypasses, underwent five bypasses in a Moscow hospital early Tuesday. The surgery was intended to correct myocardial ischemia, a condition that restricts the flow of oxygen to heart muscles and can presage a heart attack.
Bypasses: Saphenous vein taken from leg and mammary artery taken from inside upper rib cage were used to replace the blocked arteries.
Right coronary artery: Fully blocked
Left coronary artery: Three branches narrowed
Mammary artery: Used for one of the left coronary bypasses
Saphenous vein: Cut into four pieces, used for the remaining bypasses
Sources: Stephen Lange, cardiac surgeon; Bloomberg Business News, staff and wire reports