Undated (AP) _ Dan Quayle stood an irregular heartbeat away from the presidency last weekend - and may have caused many of his countrymen's hearts to lose a beat or two as well.

An unscientific survey across the country finds few people who think the vice president is ready to step in as president. Many wish President Bush would find another running mate in 1992.

But few think Bush will, even after the erratic heartbeat he suffered that for the first time in his presidency raised questions about his staying power in one of the most demanding jobs in the world.

To be sure, Quayle has some supporters. ''I think he's very competent,'' says Domenic Nicastro, 25, a cafeteria cook in Tulsa, Okla. ''Just from what I've read about him, if he were to become president, he would keep up the work President Bush has done. They both have the same personal views.''

But Tyrone Bailey of Chicago, manager of a Michigan Avenue shoe shop, is more skeptical - and apparently more typical.

''Qualified to be president?'' Bailey asked in mock disbelief. ''He's qualified to be president of the Boys' Club, not the country 3/8 Be for real.''

And in Salt Lake City, law secretary Anita Major says the first thing she said when she heard about Bush's troubles concerned Quayle: ''We don't want him at the top.''

The comments seem to conform with polling results that suggest that confidence in Quayle, never high, is falling.

A year after Bush selected Quayle, then the junior senator from Indiana, as his running mate, 52 percent of voters questioned in a poll called him unqualified to take over the presidency.

In a Washington Post-ABC News poll conducted Sunday, 57 percent of those interviewed said Quayle was unqualified to move up.

Fifty-four percent in the Post-ABC poll and 51 percent in a USA Today poll published Tuesday said Bush should find a different running mate in 1992.

Still, Americans are fair-minded, and through their comments in this street corner inquiry by AP reporters around the country ran a give-him-the-benefit- of- the-doubt qualification to their general misgivings.

Martha Jones, who recently returned from a stint as a Peace Corps volunteer in Gambia, was visiting the Folk Artery, a crafts shop in Santa Fe, N.M. She said the very same questions being asked about Quayle's qualifications had been asked about Harry Truman when he suddenly inherited the presidency from Franklin Roosevelt in 1945.

''He was a hat salesman 3/8'' she recalled of Truman, the ex-haberdasher. ''We couldn't believe anybody would pick him for vice president.''

''He's got more sense than people give him credit for or Bush wouldn't have picked him,'' said Evelyn Rotier, an owner of a restaurant near Vanderbilt University in Nashville, Tenn.

Between bites of a Chinese meal, Susan Miller, a paralegal in Hartford, Conn., said Quayle suffers from image problems.

''I think he can do the job, but a lot of people have put him down so much that I don't think enough people have enough confidence in him,'' she said.

Leroy Paige, 49, bellhop captain at the Tremont Plaza Hotel in Baltimore, called Quayle ''a standback'' - someone who hangs back and lets others take responsibility and get the glory. As did others, he noted that he heard little about Quayle during the Persian Gulf crisis.

Bruce Fulton, cutting hair at Ferg's Barber Shop in Des Moines, Iowa, asked a reporter, ''Do you want my opinion or everyone else's that has come in here today talking about it?''

He offered his: ''He's been getting a bum rap by the press because he's so young and doesn't have much experience. I think he's going to surprise people.''

New Orleans taxi driver John Warden thought Quayle is ''not a John Kennedy or a Robert Kennedy and he's sure not a George Bush.'' But still: ''If Bush is healthy and runs again, four more years might help Quayle mature.''

''He's a puppet vice president,'' said carpenter Dave Cirino, renovating an office in Philadelphia. ''Do they impeach for incompetence?'' asked Loretta Hinton, an insurance agent assistant taking a smoking break outside an office building in Raleigh, N.C.

Whatever their own opinions, few thought Bush would be likely to drop Quayle if he runs for re-election next year.

''Why change horses?'' asked John Branon, stage doorman at New York's Broadway Theater.

Cindy Merrill, staffing the information desk at a shopping mall in Springfield, Mass., said Bush would hurt himself politically to drop Quayle in 1992. ''That would show he was wrong in the first place,'' she said. ''That would undermine a lot of people's faith in him.''

''Obviously he was selected for a reason,'' added data communications analyst Ron Thomas, another smoker taking a break, this one outside the Transamerica building in downtown Los Angeles. ''I don't think Bush just picked him for popularity.''

Gloria McMahan, a legal assistant in Columbia, S.C., said Quayle probably wasn't qualified to be president, but she had no qualms about him running for re-election as vice president.

Why?

''It doesn't mean a hoot and a holler,'' she said.