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.
Mr. Bush will also continue to take the two drugs his doctors prescribed over the weekend that ultimately returned his heartbeat to normal, where it has remained since Monday morning.
"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.
Mr. Bush had also complained of feeling weak during a jogging outing about two weeks ago, which the White House doctor now sees as another hint of the condition that he estimated to be about 6 to 12 weeks old.
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.
Ironically, the president has been diagnosed with an ailment very similar to that suffered by his wife, whose overactive thyroid had its most severe effects on her eyes.
Mr. Bush used to tease his wife about glowing in the dark when she was taking radioactive iodine treatments.
Yesterday he was full of jokes about his own condition.
"Welcome from the bottom of my former fibrillating heart," he told a Rose Garden audience at a small-business awards ceremony.