CORPUS CHRISTI, Texas - The 78-year-old lawyer who was shot by Vice President Dick Cheney in a hunting accident has some birdshot in or touching his heart and he had "a silent heart attack" Tuesday morning, hospital officials said.

The victim, Harry Whittington, was immediately moved back to the intensive care unit for further treatment, said Peter Banko, the administrator at Christus Spohn Hospital Corpus Christi-Memorial in Texas.

Banko said doctors conducting a regular checkup on Whittington Tuesday morning discovered an irregularity in the heartbeat caused by a pellet, and they performed a cardiac catheterization around 10 a.m. EST. Whittington was in stable condition after treatment and expressed a desire to leave the hospital, but Banko said they would probably keep him for another week to make sure that more birdshot does not move to other vital organs.

Cheney watched the news conference where doctors described Whittington's complications. Then the vice president called him, wished him well and asked if there was anything that he needed.

A statement from Cheney's office said, "The vice president said that he stood ready to assist. Mr. Whittington's spirits were good, but obviously his situation deserves the careful monitoring that his doctors are providing."

Cheney, an experienced hunter, has not spoken publicly about the accident. Critics of the Bush administration called for more answers from Cheney himself.

The dustup over the accident and when it was made public "is part of the secretive nature of this administration," said Senate Democratic Leader Harry Reid of Nevada. "I think it's time the American people heard from the vice president."

The accident was fodder for jokes on late night TV and early Tuesday at the White House, before news surfaced about problems with Whittington's heart.

A Texas Parks and Wildlife Department report issued Monday said Whittington was retrieving a downed bird and stepped out of the hunting line he was sharing with Cheney. "Another covey was flushed and Cheney swung on a bird and fired, striking Whittington in the face, neck and chest at approximately 30 yards," the report said.

The department found the main factor contributing to the accident was a "hunter's judgment factor." No other secondary factors were found to have played a role.

Hospital officials said they knew that Whittington had some birdshot near his heart ever since Cheney accidentally shot him Saturday evening while aiming for a quail. The pellet always was at risk of moving closer since scar tissue had not had time to harden and remain in place, they said.

They said they are not concerned about other birdshot — widely estimated to be between six and 200 pieces — that might still be lodged in Whittington's body. Cheney was using 7 1/2 shot from a 28-gauge shotgun.

The doctors said Whittington did not experience classic symptoms of a heart attack, but they estimate that he probably had a minor one around 7:30 a.m. EST. They said they decided to treat the situation "conservatively" rather than conduct surgery to remove the pellet. They said he could live a healthy life with it left in place.

Asked whether the pellet could move further into the heart and become fatal, hospital officials said that was a hypothetical question they could not answer. But they said they are extremely optimistic that he will recover.

The shot was either touching or embedded in the heart muscle near the top chambers, called the atria, they said. Two things resulted:

_It caused inflammation that pushed on the heart in a way to temporarily block blood flow, what the doctors called a "silent heart attack." This is not a traditional heart attack where an artery is blocked. They said Whittington's arteries, in fact, were healthy.

_It irritated the atria, caused an irregular heartbeat known as atrial fibrillation, which is not immediately life-threatening. But it must be treated because long-term it can spur blood clots to form. Most cases can be corrected with medication.

White House physicians who attended to Whittington at the scene after Cheney accidentally shot him helped advise the course of treatment, the hospital officials said.

Whittington had initially been placed in intensive care after the accident. He had been moved to a "step-down unit" Monday after doctors decided to leave several birdshot pellets lodged in his skin rather than try to remove them.

The accident raised questions about Cheney's adherence to hunting safety practices and the White House's failure to disclose the accident in a timely way.

The Texas Parks and Wildlife Department gave Cheney and Whittington warning citations for breaking Texas hunting law by failing to buy a $7 stamp allowing them to shoot upland game birds. A department spokesman said warnings are being issued in most cases because the stamp requirement only went into effect five months ago and many hunters weren't aware of it.

Cheney's office said Monday night in a statement that Cheney had a $125 nonresident hunting license and has sent a $7 check to cover the cost of the stamp.

Katharine Armstrong, a witness to the accident and owner of the ranch where the shooting occurred, said Whittington made a mistake by not announcing that he had walked up to rejoin the hunting line after going to retrieve his bird, and Cheney didn't see him as he took a shot.

Several hunting safety experts agreed in interviews that it would have been a good idea for Whittington to announce himself. But every expert interviewed stressed that the shooter is responsible for avoiding other people.

Bush was told about Cheney's involvement in the accident shortly before 8 p.m. Saturday — about an hour after it occurred — but the White House did not disclose the accident until Sunday afternoon, and then only in response to press questions.

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