A championship in hand, the Miami Heat faces a new challenge: establishing a dynasty, both on the court and financially.

In professional sports, champions rise and fall, only to be quickly forgotten. Quick: Who won the World Series two years ago?

But some teams obtain gold-standard status through sustained performance and national cachet. (Think Lakers, Yankees, Celtics and Patriots). It carries them past one year’s triumph or disappointing season to link the team’s name to a certain exalted era. A question for the Heat: Will the franchise be the Miami Dolphins of the 1970s (prolonged excellence) or the Florida Marlins of the 1990s?

“It could be like when the Heat won [the championship] last time. Demand for tickets went way down, because the thrill of the chase was gone,’’ said Miami ticket broker Michael Lipman. “Or, they could be like the old Bulls and Lakers, and become a dynasty. Brokers made millions on those teams.”

The time between now and next year’s playoffs will test the staying power of Heatmania. For fans, a question is whether they will have to pay even more for seats in an arena that already charges some of the league’s top prices.

The Heat’s bottom line also gets particular attention in cash-strapped Miami-Dade County, which has yet to collect any money in a profit-sharing deal with the team now playing its 12th season in the tax-subsidized arena.

For sure, the Heat’s second championship in six years will spark a windfall for the team. But the Heat’s championship victory over Oklahoma City offers a particularly tricky case, experts said, given the high expectations that followed LeBron James’ arrival in 2010 and the sense of destiny denied when the team lost last year’s finals to Dallas.

According to Forbes magazine’s annual ranking of professional sports teams, the Miami Heat saw its value increase from $363 million to $457 million since 2010, when James and Chris Bosh joined Dwyane Wade as the Heat’s so-called Three Kings.

Under Forbes’ formula, the Heat is the sixth most valuable NBA franchise, behind, in order, the Lakers, Knicks, Bulls, Celtics and Mavericks.

The 26 percent spike in the wake of the LeBron signing raises a question: How much higher can it go?

“This will be a more modest increase,” said Patrick Rishe, a sports business analyst and economics professor at Webster University. “The arena has been pretty full, and if local media deals and sponsorships are locked in for a few years, this lessens the size of the value spike.”

Still, the Heat has gone from a team playing below its potential to reaching it — and matching the haughty prediction James made shortly after defecting from Cleveland that “not five, not six, not seven,” but even more championships would be his.

OFFSEASON BUZZ

David Samson, president of the Miami Marlins, said winning matters more financially than the hype surrounding a hot, newly assembled team — even one as grandiose as the Heat.

“The offseason buzz is when you sign LeBron and Bosh. It ends quickly if the team doesn’t win,” said Samson, whose Marlins won the World Series in 2003. (Their first title, in 1997, was under different ownership.) “But when you win a title, you have a much longer-lasting, almost permanent buzz. The buzz that Miami had when they signed LeBron is nothing compared to the buzz they have now."