Improv, says Howie Mandel — who balances 200 tour dates a year with two TV shows — is like a roller coaster: “The scarier the loops, the more you want to get on again.”

Translation: When the Canadian comedian takes the stage, he won’t know what the act is going to entail any more than audiences will.

Q:This is a good time to be you, with “Deal or No Deal” on network TV and in syndication, and “Howie Do It.”

A: Who would’ve dreamed “Deal or No Deal” would take me to those heights? I thought it would actually take me to those depths.

Q. Is it frustrating to watch people pass up free money?

A. As a kid who came to America because I wanted to pursue something, I understand that the difference between this country and most other countries is that we have a “go for it” attitude. … By the same token, when there’s a person I’m standing eye to eye with, and they’ve told me they’re in debt, and they have no health insurance, and the banker is offering them $250,000, and then they adamantly go, “No deal,” it’s hard for me not to throttle them.

Q. You can’t say a thing.

A. I can watch it at home and scream at the TV, and say everything I wanted to say.

Q. You’re talking about “Adult ADHD” in TV spots. How has the condition affected you?

A. I’ve been promoting a Web site, AdultADHDIsReal.com — and that’s the whole point. I don’t think that people know it’s real. … It’s hard for me to focus for any period of time, even in a conversation with my own child. I’ll hear them go, “Daddy, look at me, you’re not listening!” And I’m not. And God knows, I just want to focus and not have my mind wander.

Q. You were hospitalized recently for an irregular heartbeat. How has that colored the last few months for you?

A. I was up (in Toronto) shooting “Howie Do It,” and for insurance reasons I got a checkup … The way they correct it is, they defibrillate you. But before anesthesia, you can’t eat … I had worked all day, and I ended up passing out. So, as I stand before you on stage, I’ll wear a constant heart monitor. It’s got these little wires, like on an EKG, and it transmits information directly to my doctor’s office. If I feel like my heart’s irregular, I press a little button, it goes to him, and then he calls and says: “Howie, don’t worry. You’re fine.”