On CBS News' Face The Nation, the Democratic presidential hopeful and former New Jersey senator said he will continue his bid through the major primaries in March.
"I'm in this campaign for the duration," he said.
Bradley trails Vice President Al Gore in polls for Monday night's Iowa caucuses. In New Hampshire, the two Democrats are in locked in a statistical dead heat in polls for next week's primary.
"Iowa is a very difficult state to penetrate," Bradley said. The former basketball star said he wasn't well known when he began campaigning in Iowa. Still, Bradley added he could withstand losses in both Iowa and New Hampshire, because so far he has raised as much money as the Vice President.
Asked about the irregular heartbeat problem that's given him trouble lately, Bradley said "It doesn't interfere with my campaign (or) my schedule, doesn't interfere with my enthusiasm for the job (of President), nor my ability to do the job."
"I look at it as a nuisance. That's about it," he added.
Also on Sunday, Bradley won an editorial endorsement from The Des Moines Register, Iowa's largest newspaper. The endorsement said Bradley's "compelling vision and fundamental decency" set him apart from Gore.
But the latest Register poll of likely Democratic caucusgoers puts the Vice President at 56 percent and Bradley at 28 percent. Thirteen percent of those questioned were not sure who they support, while three percent were uncommitted.
The poll of 600 Democrats has a margin of error of plus-or-minus four percentage points.