WASHINGTON -- President Bush's irregular heartbeat was caused by an overactive thyroid, his doctors said yesterday, describing the finding as very good news because it means the president can be treated for the condition and cured.
Chief White House physician Burton Lee announced last night ** that blood test results received yesterday afternoon confirmed earlier suspicions that Mr. Bush is suffering from hyperthyroidism, which caused too many hormones to flow into his bloodstream and apparently upset the rhythm of his heart.
Testing will continue over the next few days to determine the best approach to treatment, the president's doctors said at a press conference at Bethesda Naval Hospital.
Dr. Kenneth Burman, a thyroid specialist called into the case, said treatment could take one of four forms: a radioactive iodine drink; pills to counter the effects of excess thyroid activity; surgery; or simply waiting for an inflammation, usually transient, to subside.
But Dr. Lee said the prospects of surgery in Mr. Bush's case are "basically nil."
"The president's medical team is very pleased by this turn of events," Dr. Lee told reporters. "We are now facing a medical problem that we trust will be easily treatable and resolved within a short period of time."
Until then, the president will continue to wear the portable heart monitor with which he was outfitted Monday night to detect any recurrence of the racing, erratic beat he developed while jogging Saturday afternoon.
Electrode pads affixed to Mr. Bush's chest and connected by wires to a pager-sized device on his belt pick up electrical impulses from his heart and transmit them by radio wave to a monitor near the Oval Office, where nurses maintain a 24-hour watch. The device is so sensitive that the president must turn it off when he is discussing national security issues, for fear spies will be able to hear what he's saying.
"Back to normal, and I'm feeling great," the president said at a photo session with senators yesterday morning before his hyperthyroidism was diagnosed. "Same old me."
Dr. Lee said there had been "a lot of small clues" in recent weeks that the president had recently developed hyperthyroidism. For example, Mr. Bush usually has trouble losing weight because of his hearty appetite, but "within the last week or two, he has lost three or four pounds more than anyone would have expected," the doctor said.
Despite all the extensive medical testing Mr. Bush has undergone over the last decade -- as president, vice president and presidential candidate -- he has never before been tested for hyperthyroidism, Dr. Lee said.
The doctor said Mr. Bush, 66, will undergo a thyroid scan, a diagnostic procedure that does not involve surgery, to help his doctors decide what course of treatment he should follow.
The doctors had said from the outset that there was no evidence of a heart attack, nor any sign of underlying heart disease that may have triggered the arrhythmia Saturday. But they sounded pessimistic at a press conference Monday morning about ever finding a cause, and suggested Mr. Bush might spend the rest of his life taking medication for the condition.
As it now turns out, the president falls among the 5 percent to 10 percent of patients experiencing such heart irregularities for which a treatable cause is found.