Coffee and Caffeine FAQ

I heard an interview a few years ago with a so called "coffee expert" on NPR and he said that the amount of caffine is determined by how the coffee is brewed. He stated the longer the coffee brews the more caffine results. He said perked is the strongest then drip and espresso from a pump machine (20 seconds). What I've read here is that it has less caffine but only in lesser portions than regular coffee. Someone please clear this up for me. I love espresso and full flavored coffees but my cardiologist says I need to drink decaf. :-(